clarification lot c technical list no.01 sr. ref clause ... · ref clause / page description...
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Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
1 Vol. 1 of 2;
Part 2: Employer’s
requirement;
Section IV: Bidding
Forms
Page 167 For LOT C, in Price Schedule of
Lamu 400/220kV Extension, the
capacity of transformer is 1 X
90MVA 400/220/11kV
However Technical Data Sheet
describes the capacity (Page 167
of 206) as :
• Rated Power at site conditions
(ONAF2 or OFAF) – 450MVA
(150MVA/ph)
• Rated Power at site conditions
(ONAN) 240MVA (80MVA/ph)
Please clarify which one shall
The rated power shall be as follows:
• (ONAF) 90MVA
• (ONAN) 45MVA
2 Vol. 1 of 2;
Part 2: Employer’s
requirement;
Section IV: Bidding
Forms
Price Schedule
for Lot C
According to ‘Lamu 400/220kV
Substation 400kV Single Line
Diagram’, there is no measuring
point.
But there is ‘Tariff Metering System’
in the Price Schedules of Lot C
Lamu 400kV. There is a Lot ‘220kV
– The Metering Panel (Two Panel)
Main & Backup Panel’ in the
‘Schedule No.1 Plant and
Mandatory Spare Parts from Abroad
– Item No 5.11’ and ‘Schedule No.2
Plant and Mandatory Spare Parts
from Abroad – Item No. 18.12’
Please confirm whether there is a
Lot ‘220kV – The Metering
Panel’?
If there is a Lot ‘220kV – The
Metering Panel’, which
measuring point should be?
Metering panel not required for 220kV.
3 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Substation
Control System
– Page…….
Substation Control System and
Telecommunications
Please make sure Lamu and
Hindi Substation using with SCS
or RTU? Please state the existing
Lamu 400/220kV Substation and
Hindi 220kV Substation Control
System or RTU and
Telecommunications
RTU at Hindi.
Lamu is not constructed, therefore for tendering pupose
bidders may assume SCS is installed.
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
1 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
4 Vol. 1 of 2;
Part 2: Employer’s
requirement;
Section IV: Bidding
Forms
Price Schedule
for Lot C
There is ‘Tariff Metering System’ in
the Price Schedules Lot C Nairobi
East. There are 4 Lots ‘400kV – The
Metering Panel (Two Panel) Main &
Backup Panel ‘ and 4 Lot ‘220kV –
The Metering Panel (Two Panel)
Main and Backup Panel’ in the
‘schedule No.1 Plant and
Mandatory Spare Parts from Abroad
– Item 5.10 and 5.11’ and ‘Schedule
No.2 Plant and Mandatory Spare
Parts from Abroad – Item No. 18.11
and 18.12’.
But according to ‘Nairobi East
400kV Substation Single Line
Diagram’ there are 4 measuring
points. According to ‘Nairobi East
400/220kV Substation Single Line
Diagram’, there are 5 measuring
points.
A total of 9 measuring points in this
substation, that is 18 energy meters
and one ‘400kV – The Metering
Panel’ and two ‘220kV – the
Metering Panels’.
Please make sure the quantity of
the ‘400kV – The Metering Panel’
and ‘220kV – The Metering
Panel’.
There are 4 measuring point at 400kV and 5 measuring
points at 220kV.
5 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
12.5 -Metering
Cubicle
According to ‘Procurement
Documents Volume 2 of 2- 12.5.2’.
‘Main and Check meters may be
housed in the same cubicle’, but
there are ‘ The Metering panel (Two
Panel) Main & Backup Panel’ in the
‘Schedule No.1 Plant and
Mandatory Spare Parts from Abroad
– Item No 5.10 and 5.11’ and
‘Schedule No.2 Plant and
Mandatory Spare Parts from Abroad
– Item 18.11 and 18.12’
Please confirm that Main Checks
meters should be housed in one
metering cubicle or two?
One panel for 400kV and 2 panels for 220kV.
2 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
6 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Appendix B Existing Telecom and OPGW
System
Having an overview of the
documents that we have
downloaded, we notice that the
Vol 2- Appendix B – Existing
Telecom and OPGW System is
missing
Information is attached in the addendum.
The following drawing shall be used for the purpose of the
tender:
A. Common for all Substation 1KHD636398
7 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Appendix A Plan and Sectional Tender
Drawings
Can you please provide plans
and sections of Lamu 400kV
Switchyard, Hindi 220kV
Substation and Koma Rock
220kV Substation?
Revised substation layout will be uploaded as addendum.
8 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Status of Substation Land Is the land requisition for Nairobi
East 400kV Substation site and
the resettlement on the
responsibility of the Employer or
not?
Yes.
9 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Clause 19.5 &
Clause 19.11
Water Supply for Substation In Clause 19.5, Volume 2 of 2 of
Lot C, water for the substation is
taken by drilling well, while
Clause 19.11 states that water for
the substation is from local tap
water. Please confirm the water
source for the substation.
When ever possible, the water shall be from the main
water supply source. However, in absence of the main
water supply pipe, bidders shall assume the well is
required. The provision of water shall be at the
Contractor's expense
10 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Nairobi
East/Lamu
Fire figthing Can you please confirm if water
fire-fighting system shall be
provided or not?
Water firefighting system shall not be used inside the
Control building.
3 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
11 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Reactive Compensation for Auto-
Transformers
Please clarify the configuration
plan for reactive compensation of
Nairobi East 400kV Substation:
(1) whether the two circuits of
outgoing lines to Lamu require
high resistance (on the drawings
provided, each outgoing line is
with 100MVar parallel line of high
resistance)? (2) a 4×300MVA
transformer is added in the new
Nairobi East 400kV Substation,
for which only two voltage
classes of 400/220kV are
provided, whether a capacitor
shall be installed to compensate
the reactive loss of transformer?
Please clarify the installation
position and capacity.
Details are shown in the SLD and follow accordingly.
12 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Safety & Stability Control Device Design of the safety and stability
control device is related to the
systemic projects of the State
Grid of Kenya, which is not only
applicable to the new and added
substations in this bidding.
Please clarify whether the design
of safety and stability control
device is included in this scope of
bidding? If it is, in which Lot
included?
Clarification not clear.
13 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Appendix A Transformer Capacity At Lamu substation there is need
to construct another new
400/220kV transformer, whose
capacity is about 90MVA, but in
the TECHNICAL SCHEDULES
the capacity is 450MVA
(150MVA/ph), please clarify
which one is right?
Refer to item no. 2
4 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
14 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Appendix A Transformer Capacity In new NAIROBI EAST
Substation the capacity of
transformer is 450MVA,but in the
TECHNICAL SCHEDULES the
capacity is 300MVA, please
clarify which one is right?
The 400/220/11kV Transformers shall be as follows:
• Rated (ONAF2 or OFAF) 300MVA (100MVA/ph)
• Rated (ONAN) 180MVA (60MVA/ph)
15 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Appendix A Drawing (Existing
Telecommunications and OPGW
System)
N/A The following drawing shall be used for the purpose of the
tender:
A. Common for all Substation 1KHD636398
16 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Appendix A i) Please provide us the distance
between Koma rock 220kV
substation and the Nairobi east
220kV substation, for we need to
evaluate the connection works of
the 220kV busbars.
ii) For Nairobi East 400/220kV
Substation, please provide us the
bay width of the 400kV and
220kV switchyard.
iii) For Nairobi East 400/220kV
Substation, is the 220kV
switchyard far away from the
400kV switchyard? where shall
be the control building located,
and also the staff quarter? there
is no overall plan of the whole
substation.
i) and ii) Refer to tender drawings as specified in item 15.
Howerver it’s the responsibility of the Contractor to design
the substations.Bay width shall be determind by
Contractor.
iii) The sizes of the proposed buildings are indicated in the
tender specification and schedule no. 4 of the price
schedules. The contractor to propose a suitable
location and this shall be shown in the proposed bid
drawings.
5 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
17 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Clause No. 1.4 The terminal points, the
connections between the 400kV
terminal towers and the
substation gantry structures are
included in Lot C, but we have
checked the bidding document of
Lot A, Clause 1.4, the
connections has been divided
into the work scope of Lot A. so
the two documents are conflicting
with each other. in our opinion,
the connections shall be in the
work scope of transmission
line(Lot A), please clarify.
The connections for the transmission lines scope is right
upto the gantries. The down droppers and clamps shall be
provided by the substation contractor. The bonding of the
ground wire to the substation earth grid shall be
responsibility of substation Contractor.
18 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Price Schedule
for Lot C -
Nairobi East
Substation
Item 11.1, Item 10.5, Item 10.6 The quantity these equipment in
the Price Schedule and the
bidding drawings are
contradicting. Please clarify.
Price schedule is corrected and revised schedule is
attached in the addendum.
19 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Price Schedule
for Lot C -
Nairobi East
Substation
Please clarify the different
application of the price schedule
Item 26.8(Substation perimeter
fence including security) and Item
26.9(Substation perimeter fence).
26.8 is the Substation perimeter fence with the security
system - security camera connected to Control Center in
Nairobi
26.9 Second layer fence.
20 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Price Schedule
for Lot C -
Lamu 400kV
Substation Ext.
Item 1.3, Item 1.4, Item 1.6, Item
2.3, Item 2.11, Item 2.13
The quantity these equipment in
the Price Schedule and the
bidding drawings are
contradicting. Please clarify.
Price schedule is corrected and revised schedule will be
uploaded in the addendum.
6 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
21 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Clause 1.2.2 The substation work at Lamu 400kV
will comprise the followings:
i. Extension of existing 400 kV
switchyard to accommodate a
transformer feeder bay
ii. Supply, install and commission
One (1) 400/220 kV 90 MVA
transformer
iii. Supply, install and commission
Two (2) x 100 MVAr line connected,
switchable shunt reactors on
Nairobi East 400kV OHL lines.
But after we checked the Price
Schedule of Lamu, we found that
there are several item that should
not in the scope of Lot C, we
think these items shall be
conducted by others. Please
clarify. These items are listed
below for your reference.
Item 26.8 Substation perimeter
fence including security
Item 26.13 Substation gatehouse
Item 26.14 Substation control /
relay building
Item 26.17 Sewage System
Item26.18 Carpark
Item31.6 Single Unit staff house
Item31.7 Double Unit staff house
Item31.9 Access road outside the
sub station
and also, for the items these are
not listed here , we assume that
we only conduct the works
related to the 400/220kV
transformer and the 400kV shunt
reactors.
These are required. However price schedule is revised
and will be uploaded as addendum.
22 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Clause 1.6 (G) Wind Load “For design purposes a basis
wind speed of 39m/s shall be
assumed.”
Please confirm our following
understanding:
According to IEC-60286, the
basis wind speed of 39m/s is the
10-min wind speed at 10m above
ground and with a 50-year return
period.
The Basic Wind Speed 39m/s is the 3s gust. This has to
be converted to Reference wind speed i.e into 10-min
average speed.
23 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Substations mentioned in Lot A
and Lot B are not in accordance
with substations mentioned in Lot
C, please clarify it. There are two
overhead feeders to ISINYA, and
is ISINYA included in Lot C?
From Nairobi East 400kV, there are: 2 x 400kV OHL to
Lamu and 2 x 400kV OHL to ISINYA. The description on
the Lot A and B to be corrected.
7 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
24 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
The bid document mentioned that
the 220kV busbar of NAIROBI
EAST should be joint to KOMA
ROCK 220kV busbar, then how?
Is this part included in Lot C? If it
is, please provide the layout of
the two substations.
The existing KOMA ROCK substation is construted by
others and it is not part of Lot C scope. Revised
substation layout will be uploaded as addendum.
25 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Price Schedule
for Lot C -
Lamu 400kV
Substation Ext.
Item 10.1 Please clarify the item of 10.1
mentioned in Price
Schedules_Lot C_Lamu
400kV.xls is correct or not.
No requirements for new LVAC board. Revised price
schedule attached.
26 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
The manufacturer lists and the
information of control and
protection devices in extension of
existing substation.
The existing substations (Lamu 400kV and 220kV Koma
Rock) are not constructed yet and thus this information is
not available.
27 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
If there is any difference required
in the BOQ, technical
requirements, drawings, such as
the quantity and capacity of the
power transformer, which
requirement could we follow?
Where there are descrepancies please clarify.
28 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Short-circuit current: It is 50kA for
400kV and 40kA for 220kV in
Section J of Schedule of
Technical Particulars, but we
think 40kA for 400kV and 31.5kA
for 220kV is enough
(because this is the HV
equipment requirement), please
clarify.
Please comply as required.
8 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
29 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
The 400kV transformer type in
LAMU substation: In TECHNICAL
SPECIFICATIONS and
Price Schedules_LotC_Lamu it is
auto-transformer, but for tender
drawing legend, it is an
ordinary three-phase transformer
but not auto-transformer. Please
clarify.
It's Auto-Transformer. The revised SLD will be uploaded
in the addendum.
30 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
400kV Disconnector type:
According to the attachment
drawings, the disconnector is
horizontal center break type.
Whether can it adopt three-
column horizontal rotary
disconnectors.
The information shown in the tender drawings are for
tendering pupose only. The offerered plant items shall be
inline with the requirements in the specifications.
31 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Earthing conductor size: It is said
“Main earthing system shall
comprise complete set of copper
tapes (300 mmsq)” in Section 7
of Price Schedules, we think the
earhing conductor size should be
calculated based on IEEE 80 and
submitted to owner for approval
but not confirmed 300 mmsq
now. Please clarify.
For the purpose of the tendering please use the size
specified.
32 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
In Price Schedules_Lot C_NE,
the 220kV CT quantity maybe
changes from 21 to 24.Please
clarify.
In Price Schedules_LotC_Lamu,
the quantity of 400kV
Disconnector with one earth
switch maybe changes from 2
to7, and the quantity of 400kV
Disconnector with two earth
switches
Maybe changes from 3 to 0.
Please clarify.
Price schedule is corrected and revised schedule will
uploaded as addendum.
33 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
In Lamu SLD " PE " equipment is
shown which is not available in
the price schedule. Please clarify
this item.
SLD is corrected and revised SLD will be uploaded in the
addendum.
9 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
34 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Please provide the soil resistivity
and soil bearing capacity value ,
water table level of Nairobi east
substation.
The bidders shall assume the conditions based on their
experience and hence the reason for the site visits. Soil
resistivity and soil bearing capacity value , water table
level measurements is part of the design scope of the
contractor.
35 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Please provide the plot area
available for constructing the
proposed green field substation.
The available plot area is approximately 1500m x 300m.
The proposed substation footprint for 400kV and 220kV is
given in the tender drawings.
36 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Please provide the overall plot
plan indicating the location of
control room, DG building (if
any), gate house , staff housing
units, store , control room.
Bidders shall propose the plan as per the requirement in
the Technical Specification and bid documents. The
design of substation including the layout plan is part of
Contractor's scope.
37 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Kindly provide survey details in
the form of contour level or in the
form of .CSV file and site co-
ordinates for layout boundaries
Bidders shall undertake this work upon contract award.
For the purpose of the tendering the bidders shall assume
based on their experience. This will be part of contractors
scope.
38 Vol. 2 of 2;
Part 2: Employer’s
requirement;
Section VI:
Technical
Specifications For
Substation and
Overhead Line
Termination
Please provide us the details of
rooms required for the control
room.
The bid documents are clear on the requirements
10 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
39 Lot
C_Appendix
C.1_schedule 1
of Technical
Particulars_NE
ast_Rev 1,
Page 45 of 206
Please furnish the Rated Voltage
– MOA of 220kV surge arrester.
As per Bidding Document Volume 2 of 2, Section VI,
Technical Specifications , section 7.1 paragraph 1 Bidders
are expected to carry out insulation studies which will
produce the required surge arrester characteristics. For
the tendering purpose the bidders shall propose a
standard rating e.g. 198kV.
40 Lot
C_Appendix
C.1_schedule 1
of Technical
Particulars_NE
ast_Rev 1,
Page 193 of
206
Please furnish the discharge
current of 108kV, Class 4
lightning arrester to be mounted
near the neutral reactor.
For the tendering purpose the bidders shall propose a
standard rating.
41 Price schedule
1 Quantity
mismatch KET-
2014-D-
001_Nairobi
East 400kV
SLD &
Protection Rev
3
As per price schedule 1 item 10.5
Earthing transformer - 3 Nos
As per SLD
Earthing transformer - 4 Nos
As per layout
Earthing transformer - 4 Nos
Please confirm the actual
requirement.
Price schedule is corrected and revised schedule will be
uploaded in the addendum.
42 Price schedule
1 Quantity
mismatch KET-
2014-D-
001_Nairobi
East 400kV
SLD &
Protection Rev
3
As per price schedule 1 item 10.6
Neutral earthing resistor - 3 Nos
As per SLD
Neutral earthing resistor - 4 Nos
Please confirm the actual
requirement.
Price schedule is corrected and revised schedule will be
uploaded in the addendum.
43 Price schedule
1 Quantity
mismatch KET-
2014-D-
001_Nairobi
East 400kV
SLD &
Protection Rev
3
As per price schedule 1 item 11.1
Bank of 3 Nos of 100 MVA single
phase autotransformer - 3 Nos
As per SLD
Bank of 3 Nos of 100 MVA single
phase autotransformer - 4 Nos
As per layout
Bank of 3 Nos of 100 MVA single
phase autotransformer- 4 Nos
Please confirm the actual
requirement.
Price schedule is corrected and revised schedule will be
uploaded in the addendum.
11 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
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Clarification Lot C Technical List No.01
44 Price schedule
1 Quantity
mismatch KET-
2014-D-
001_Nairobi
East 400kV
SLD &
Protection Rev
3
As per price schedule 1 item
12.12
Externally mounted CT's for 3 x
Interbus transformer bays
As per SLD
Externally mounted CT's for 4 x
Interbus transformer bays
Please confirm the actual
requirement.
Price schedule is corrected and revised schedule will be
uploaded in the addendum.
45 Price schedule
1 Quantity
mismatch KET-
2014-D-
001_Nairobi
East 400kV
SLD &
Protection Rev
3
As per price schedule 1 item
12.13
11kV AIS busbar - 3 Lots
As per layout
11kV AIS busbar - 4 Lots
Please confirm the actual
requirement.
Price schedule is corrected and revised schedule will be
uploaded in the addendum.
46 Price schedule
1 Quantity
mismatch KET-
2012-D-002
Nairobi East
220kV SLD
Rev 2
As per price schedule 1 item 2.10
220kV Single phase current
transformer - 21 Nos
As per SLD
220kV Single phase current
transformer - 24 Nos
Please confirm the actual
requirement.
Price schedule is corrected and revised schedule will be
uploaded in the addendum.
47 Price schedule
1 Quantity
mismatch KET-
2014-D-
001_Nairobi
East 400kV
SLD &
Protection Rev
3
As per price schedule 1 item 29.2
Transformer fire wall - 3 Lots
As per SLD
Transformer fire wall - 4 Lots
Please confirm the actual
requirement.
Price schedule is corrected and revised schedule will be
uploaded in the addendum.
48 Price schedule
1 Item Nos :
1.12
1.13
1.14
& 400kV SLD
KET-2014-D-
001 Rev 3
As per price schedule 1
Metering core is 0.5, Protection
core is with 3P
As per SLD
Metering core is 3P/1.0,
Protection core is with 3P
Please confirm whether metering
core shall be 0.5 or 3P/1.0.
Class 1.0 shall be provided. Revised schedule will be
uploaded in the addendum.
49 Price schedule
1 Item Nos :
2.12 & 220kV
SLD KET-2014-
D-002 Rev 2
As per price schedule 1
Metering core is 0.5, Protection
core is with 3P
As per SLD
Metering core is 3P/1.0,
Protection core is with 3P
Please confirm whether metering
core shall be 0.5 or 3P/1.0.
Class 1.0 shall be provided. Revised schedule will be
uploaded in the addendum.
12 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
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50 Price schedule
1 Item no : 2.5
& Technical
schedule page
45 of 206
As per price schedule 1
220kV lightning arrester- Class 3.
As per tech schedule 1
220kV lightning arrester- Class 4.
Please confirm the actual
requirement.
Class 4 shall be offered.
51 Price schedule
1 Item nos:
1.15 , 2.13 ,
220kV SLD
KET-2014-D-
002 Rev 2
,400kV SLD
KET-2014-D-
001 Rev 3,
Section VI
clause 5.2,
page 81 of 385
As per price schedule 1
Metering class accuracy of
current transformer in combined
CT/VT unit- 0.2
As per SLD
Metering class accuracy of
current transformer in combined
CT/VT unit- 0.2s
As per specification
Metering class accuracy of
current transformer in combined
CT/VT unit- 0.2s
Please confirm the actual
requirement.
Shall be 0.2s. (Also applicable for Lamu and Hindi)
52 Section VI
clause 5.2,
page 81 of 385
& 220kV SLD
KET-2014-D-
002 Rev 2
As per specification it is stated as
"Tariff Metering shall be provided
on each incoming 220kV line".
But in SLD, tariff metering is also
provided in 220kV transformer
incomer feeders. Please clarify.
Please comply as required.
53 Price schedule
1 item no : 2.12
As per price schedule 1, 50VA for
each winding to be provided for
220kV inductive voltage
transformer. Since it is a two
winding transformer, 100VA is
sufficient. But price schedule 1
calls for 150 VA. Please clarify.
50VA for each winding shall be provided. For 2 winding
100VA is accepted.
54 Section VI -
Technical
specification,
clause 14.35,
page 272 of
385 - Auto
transformers
As per specification, no fire
protection is required for
transformers.
Hence we are not envisaging any
provisions in the transformer for
fire protection. Please confirm.
Correct.
55 Lot
C_Appendix
C.1_schedule 1
of Technical
Particulars_NE
ast_Rev 1,
Page 168 of
206
The tertiary winding capacity is
given as 70 MVA in transformer
technical datasheet. We find this
value to be very high when the
transformer tertiary is going to be
loaded with 500 kVA Auxiliary
transformer. Please confirm the
correctness of the value.
The minimum rating of the tertiary winding shall be at least
1/3 of the transformer main winding MVA rating.
13 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
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Clarification Lot C Technical List No.01
56 Lot
C_Appendix
C.1_schedule 1
of Technical
Particulars_NE
ast_Rev 1,
Page 165 of
206 & 400kV
SLD KET-2014-
D-001 Rev 3
As per technical schedule
autotransformer is said to be with
stabilising tertiary winding but as
per SLD, tertiary winding is to be
loaded. Please clarify.
The tertiary winding shall be utlised for auxiliary/earthing
transformer for local LVAC supply.
57 Price schedule
1 Item 7.1 &
Section VI -
Technical
specification,
clause 3.4,
page 47 of 385
As per price schedule 1 "Main
earthing system shall comprise
complete set of copper tapes
(300 sqmm)," is given.
As per specification it is stated as
" The use of bare, stranded,soft
drawn copper is preferred by
KETRACO."
As per datasheet, bare copper
conductor , lead sheathed copper
conductor, copper flat bars
Please confirm which one to be
followed whether copper flat or
stranded bare copper conductor
or lead sheathed copper
conductor for below ground
earthing.
Both accepted. Please refer to item no. 31.
58 Price schedule
1 Item 7.1 &
Section VI -
Technical
specification,
clause 3.4,
page 47 of 385
As per price schedule 1 "Main
earthing system shall comprise
complete set of copper tapes
(300 sqmm)," is given.
As per specification it is stated as
" The use of bare, stranded,soft
drawn copper is preferred by
KETRACO."
As per datasheet, bare copper
conductor , lead sheathed copper
conductor, copper flat bars
Please confirm which one to be
followed whether copper flat or
stranded bare copper conductor
or lead sheathed copper
conductor for above ground
earthing.
Refer to item 57 above.
14 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
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Clarification Lot C Technical List No.01
59
Section VI -
Technical
specification,
clause 17,
page 311of 385
& Appendix A
As per specification it is stated as
" The resistors shall be rated for
10 seconds and the current
ratings and ohmic value shall be
as shown in the drawings in
Appendix A. The neutral earthing
arrangement shall be as per
requirement indicated in drawings
(Appendix A)." But in the
drawings provided in Appendix A
does not show the requirement of
the neutral earthing resistor and
the neutral of earthing
transformer is solidly earthed.
Please revise the drawings and
provide the necessary current
rating and ohmic value of neutral
earthing resistor in the drawing.
NER is required. Revised drawing will uploaded as
addendum.
60 Section VI -
Technical
specification,
clause 16.1,
page 307of 385
Lot
C_Appendix
C.1_schedule 1
of Technical
Particulars_NE
ast_Rev 1,
Page 196 of
206
Lot
C_Appendix
C.1_schedule 1
of Technical
Particulars_NE
ast_Rev 1,
Page 207
Please clarify the requirement for
Limitation and withstanding of
fault current in neutral about
Earthing Transformers.
As per earthing transformer
specification , it is mentioned
that” Earth fault current required
Amp. 1050”、 “Earthing/auxiliary
transformers shall be capable of
withstanding for a period of 30
seconds”.
As per earthing transformer
technical schedule it is
mentioned that” Limitation and
withstanding of fault current in
neutral for 30s:1050A”.
However, as per neutral earthing
resistor technical schedule, The
resistors limitation and
withstanding of fault current is
500A for 10s.
Comply as required.
61
Price schedule
1 Item nos :
1.13 ,
As per price schedule 1 , busbar
inductive voltage transformer Qty
is 2 Nos. (1 No. per
busbar)
As per SLD, Busbar Inductive
voltage transformer is
represented as 3 x
400V/Sqrt(3)/110V/Sqrt(3).
Please confirm the actual
requirement.
Shall be 1 x Single Phase with 2 windings.
15 of 33
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Clarification Lot C Technical List No.01
62
Price schedule
1 Item no : 11.3
& 400kV SLD
KET-2014-D-
001 Rev 3
As per price schedule 1, one set
of bushing CT has to be provided
for neutral reactor protection.
Please clarify whether the CT
shown in SLD near neutral
reactor is bushing type or outdoor
post type.
Bushing type.
63 KET-2014-L-
104_Nairobi
East 400kV
Layout &
Elevation Rev
2
KET-2014-L-
105_Nairobi
East 220kV
Layout &
Elevation Rev
2
Section VI -
Technical
specification,cl
ause 19.17.16,
page 361 of
385
We noticed a discrepancy
between the drawings in annex
and the specification :
It is specified 7,3m for major
access road (we understand for
heavy roads) and 5m for access
road (we understand other roads
than heavy ones).
In the drawings and according to
the scale, roads are shown of 5m
for heavy roads and main access
roads and of 3m for other ones.
Please confirm that we can
consider 5m for heavy roads and
3m for the other ones.
5m for heavy or main access/perimeter roads in the
substation and 3m for maintenance access, as shown in
the layout drawings.
64 Section VI -
Technical
specification,cl
ause 18, page
312 of 385
Please clarify whether diesel
generator has to be placed in
separate building.
Outdoor type/design with noise enclosure shall be
provided. Bidders shall propose in the bid submissions.
65 Section VI -
Technical
specification,cl
ause 1.6, page
4 of 385
We presume that the maximum
wind speed of 140km/hr given in
specification is 3s gust wind
speed. Please confirm.
See item no. 22
66 Section VI -
Technical
specification,cl
ause 1.6, page
4 of 385
Please confirm whether the Ice
Loading details are applicable? If
so please clarify the weight of Ice
to be considered per meter.
No.
67 General Please clarify whether staff
housing units and store are
located outside the substation or
inside the substation.
Outside the switchyard area but within the substation
land.
16 of 33
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Clarification Lot C Technical List No.01
68 400kV SLD
KET-2014-D-
001 Rev 3
There is no switch between the
auto transformer and auxiliary
transformer. So the failure of
auxiliary transformer will cause
the trip of the CB at HV side of
auto transformer and enlarge the
accident. So we suggest that a
falling type safety fuse should be
set between the auto transformer
and auxiliary transformer,
then, the main transformer will
not tripped if there is only some
fault with the auxiliary
transformer, which will make the
grid more stable.
Please follow to the requirements in the tender.
69 KET-2012-D-
002 Nairobi
East 220kV
SLD Rev 2
As per the 220KV Single line
diagram, 220KV busbar rating
specified as 2000A, but the CT
rating specified as 2500-1500/1A.
Please confirm / clarify 220kV
Busbar rating and CT rating.
Please follow to the requirements in the tender.
70 Section VI -
Technical
specification,cl
ause 4.2.4.3,
page 59 of 385
As per specification, shunt
reactor circuit breakers are to be
provided for special duty
applications based on point on
wave scheme. Hence , please
clarify whether point on wave
relay is exclusively required for
these breakers or pre-insertion
resistor can be used. Price
schedule does not call for any of
these items.
No. Please follow to the requirements in the tender.
71 General Please provide us the initial
Tension on 400kV & 220kV
Phase conductors and shield wire
for tower design
Bidders shall use their experience and engineering
knowledge to determine this.
72 Section VI -
Technical
specification,
Civil works.
clause 19.7.16,
page 361of 385
Kindly confirm whether the
dimension & type of the road,
within the compound of staff
housing, could be considered as
3m & concrete road respectively.
5m and concrete/tarmac road.
17 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
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Clarification Lot C Technical List No.01
73 Lot
C_Appendix
C.1_schedule 1
of Technical
Particulars_NE
ast_Rev 1,
Page 169 &
PAGE 4 of 206
As per transformer technical
datasheet ,page 169 the short
circuit
currents are defined as :
- 50kA/2s for HV terminals and
windings (400kV)
According to the general
datasheet and SLD
- 40kA/1s for 400kV switchgear
Please clarify : what is the short-
circuit current to be taken
into account for 400kV terminals
and windings of transformer?"
For Transformer: 50kA/2s for HV terminals (i.e. the
Bushings)
74 Lot
C_Appendix
C.1_schedule 1
of Technical
Particulars_NE
ast_Rev 1,
Page 169 &
PAGE 25 of
206
As per transformer technical
datasheet ,page 169 the short
circuit
currents are defined as :
- 40kA/2s for LV terminals and
windings (220kV)
According to the general
datasheet and SLD
- 31.5kA/1s for 220kV switchgear
Please clarify : what is the short-
circuit current to be taken
into account for 220kV terminals
and windings of transformer?"
For Transformer: 40kA/2s for HV terminals (i.e. the
Bushings)
75 General Please provide the capacitance
value of 400kV and 220kV CVT
For tendering purpose the bidders shall propose a
standard/typical value. (Applicable for all Substations
under Lot C)
76 General Please specify the number of
spare feeders to be considered in
LVAC switchgear.
For tendering purpose the bidders shall offer 2 spares on
each section of the busbar.
77
----
Kindly provide the design factor
of safety for normal condition and
short circuit force condition for
the design of substation steel
structures.Or else specify the
standard of practice to be
followed for the same.
This shall be in accordance to the international standards
(e.g. IEC) as specified in the tender documents.
78 General
Topographic
Survey
Drawing
Please provide us the
topographic survey drawing for
all three(3) substation in order to
have a general information to
calculate earthworks quantity that
will be involved for substation
platform preparation.
The bidders shall be guided by the findings of the site
visit. Topographic survey is part of contractor's scope.
18 of 33
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Clarification Lot C Technical List No.01
79 Remote end
scope of works -
Protection and
telecommunicat
ion
We presume that there is no
remote end scope of work in the
following substations:
1. Isniya -1&2
2. Lamu -1&2
3. Embakasi
Please confirm.
No remote end works at Isinya and Embakasi. Works at
Lamu shall be covered under Lamu Extension scope.
80 Appendix D.1,
Schedule No.1,
Item No.5, 5.8
Please furnish the make,type and
location of NCC and RCC.
Refer to item No. 6
81 Appendix D.1,
Schedule No.1,
Item No.3,
400kV
Protection
system, 3.1,
Overhead line
feeder
protection
Lot C_Tech
Spec_Section
V, Clause
8.2.1.2,
400/220kV
Overhead Line
Feeders, C
Main
protection,
Please provide the make and
type of Main -2,Numerical current
differential relays for the following
lines to be matched with remote
end:
1. Isniya -1
2. Isniya -2
3. Lamu-1
4. Lamu -2
Information on remote end protection is currently not
available, therefore for the purpose of the tendering
bidders shall propose a suitable type/make as specified
the technical schedule.
82 Appendix D.1,
Schedule No.1,
Item No.4,
220kV
Protection
system, 4.1,
Overhead line
feeder
protection
Lot C_Tech
Spec_Section
V, Clause
8.2.1.2,
400/220kV
Overhead Line
Feeders, C
Main
protection,
Please provide the make and
type of Main -2,Numerical current
differential relays for the following
lines to be matched with remote
end:
1. Embakasi
Refer to item 81.
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Clarification Lot C Technical List No.01
83 Appendix D.1,
Schedule No.1,
Item No.3,
400kV
Protection
system, 3.3
Transformer
protection
Lot C_Tech
Spec_Section
V, 8.2.1.4
400/220kV
Auto-
transformers
(400kV side),
C. Auto-
Transformer
protection.
As per price schedule,
As per technical specification,
Main - 2 shall be of High
impedance 3-winding transformer
differential protection with
stabilizing resistor and metrosil.
Please provide the datasheet for
the same.
Proposed data for High Impedance :
1) Relay Type - High Impedance
2) Relay Operating Principle - Voltage or Current
3) Relay Operating Time < 40ms
4) Metrosil Available - Yes
5) Stabilizing Resistor Available - Yes
Revised data sheet will be uploaded as addendum.
84 Appendix D.1,
Schedule No.1,
Item No.4,
220kV
Protection
system, 4.1,
Overhead line
feeder
protection.
Lot C_Tech
Spec_Section
V, Clause
8.2.1.2,
400/220kV
Overhead Line
Feeders, h.
Autoreclose
Lot
C_Appendix
C.1_Schedule
of Technical
Particulars_NE
ast_Rev 1_25-
05-
15,D.Protection
and indication
system.
As per price schedule and
technical specification, auto
reclose and undervoltage relay
should be a separate relay.
But in technical datasheet, auto
reclose and undervoltage is a
part of main protection distance
and line differential (21/87L).
Please confirm whether the auto
reclose and undervoltage relay is
integrated function or seperate
relay.
Should be separate.
20 of 33
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Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
85 Appendix D.1,
Schedule No.1,
Item No.3, 3.3
Transformer
protection.
KET-2014-D-
001_Nairobi
East 400kV
SLD &
Protection Rev
3
In price schedule, Main-1
protection of transformer is
numerical 3- winding biased
transformer differential protection.
As per SLD, only 1 CT core is
allocated at HV side and LV side
each. There is no CT core at
Neutral end. For 3-winding
differential protection, one more
CT core should be placed at
Neutral end.
Please confirm whether the main -
1 protection is 2 winding
differential protection or 3 winding
differential protection.
2 CTs at HV & LV winding are also sufficient for protection
of the transformer.
Proposed to maintain as Main 1 as 2 winding differential.
86 Appendix D.1,
Schedule No.1,
Item No.3, 3.2
Tie protection
and 3.3
Transformer
protection.
Lot C_Tech
Spec_Section
V, Clause
8.2.4.1,
400/220kV
Auto-
transformers
(400kV side), d.
400 kV HV
connections
protection.
As per price schedule, stub
protection is required.
As per technical specification,
High voltage connection (HVC)
protection is required.
Please confirm whether both the
protection are same.
No. Stub Protection is for the Tie Bus. Stub Protection
shall be used for OHL bay while HVC shall be used in
Transformer bays.
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Clarification Lot C Technical List No.01
87 Appendix D.1,
Schedule No.1,
Item No.3, 3.3
Transformer
protection.
Lot
C_Appendix
C.1_Schedule
of Technical
Particulars_NE
ast_Rev 1_25-
05-15, D.
Protection and
indication
system, Main
transformer /
Reactor biased
differential
protection 87
As per price schedule,
As per technical datasheet, REF
for HV, LV is an integrated
(inbuilt) feature for main
transformer biased differential
protection 87.
Hence there is no separate REF
relay required.
Please confirm whether the
understanding is right.
If seperate relay is required
please update the same in price
schedule.
Yes, correct.
88 KET-2012-D-
002 Nairobi
East 220kV
SLD Rev 2
Appendix D.1,
Schedule
No.1,Item No. 5
SCS,
Telecommunic
ation &
associated
equipment,
220kV Indoor
Control Panels.
As per SLD, Circuit breaker
cubicle shall be 8 Nos.
As per price schedule, 220kV
Circuit breaker cubicle is of 6
Nos.
2 Nos of tie circuit breaker
cubicles are missing in price
schedule.
Please update the same in the
price schedule.
Price schedule revised and will be uploaded as
addendum.
89 Lot C_Tech
Spec_Section
V,Clause 14,
Power
transformer
Please confirm the insulation
class of auto transformer.
Please refer to IEC 60076 and comply accordingly.
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Clarification Lot C Technical List No.01
90 Lot C_Tech
Spec_Section
V,Clause 15,
Shunt Reactor,
15.2.3, Neutral
earthing.
KET-2014-D-
001_Nairobi
East 400kV
SLD &
Protection Rev
3
As per technical specification,
neutral earthing shall be directly
connected to earth.
But as per SLD and requirement,
the neutral shall to earthed via a
Neutral Grouding Reactor (NGR).
Please confirm.
The drawing is revised and will be uploaded as
addendum.
91 KET-2014-D-
001_Nairobi
East 400kV
SLD &
Protection Rev
3
Lot C_Tech
Spec_Section
V,Clause 16,
auxiliary/earthin
g transformers.
Please confirm whether the 11kV
side of auxiliary/earthing
transformer shall be directly
earthed or earthed via a resistor.
Earthed via NER.
92 Lot C_Tech
Spec_Section
V,Clause 11,
LV service
equipment,
11.2, Scope of
works
Lot
C_Appendix
C.1_Schedule
of Technical
Particulars_NE
ast_Rev 1_25-
05-15, I. LV
services
equipment, 1.
110V DC
system-
substation
services
supply.
As per specification, minimum
discharge capacity of 110VDC is
400AH.
As per datasheet, minimum
discharge capacity is 250Ah.
Request you to confirm the exact
value so that every bidder will be
in the common platform.
For the purpose of tendering the bidders shall consider
400AH.
23 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
93 Appendix D.1,
Schedule No.1,
Item No.3, 3.3
Transformer
protection.
We presume that guard
protection is transformer
mechanical protection like
(bucholz, PRV, oil temperture
indictor, winding temperature
indicator etc..)
Yes, correct.
94 Lamu Lot
C_Appendix C
2_Schedule of
Technical
Particulars_La
mu 400kV
ExtPage 164 of
206 & KET-
2014-D-303
Lamu 400kV
SLD REV 2
In Transformer technical
datasheet, it is mentioned as
single phase auto transformer
with vector group YNa0d but in
SLD the representation is shown
as power transformer.
Please clarify whether it is auto
transformer or power transformer
and also whether it is single
phase transformer or 3 phase
transformer.
See item no. 29.
95 Lamu Lot
C_Appendix C
2_Schedule of
Technical
Particulars_La
mu 400kV Ext
Page 164 of
206
In transformer technical
datasheet altitude is given as
1600m but altitude of lamu
substation is 216m. Please
confirm and revise the technical
schedule .
Lamu is 216m and revised schedule will be uploaded.
96 Lamu Price schedule -
4 , Item : 26.14
As per civil works price schedule -
4, substation control/relay
building to be provided with area
40m x 32m. Lamu is an already
existing substation and hence we
presume control building is
already existing and the same
shall not be considered in present
scope. Please confirm whether
our understanding is correct.
Incase control building is required
to be constructed , please
provide the details of individual
rooms in the control building.
Bidders shall include new control building as required in
the price schedule.
97 Lamu General We presume space for control
and protection panels for the
proposed extension is already
available in the existing control
room. Please clarify.
Refer to item 96.
24 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
98 Lamu Price schedule
1 Item 7.1
"Main earthing system for the
complete substation:- Substation
underground earthing system
with rating of 40kA, 1 Sec for
400kV and 31.5kA, 1 Sec for
220kV."
We presume main earth mat is
already existing and 400kV
equipment earth risers alone
considered in present scope. No
earthing works is considered in
220kV system. Please confirm.
Earthing would be only required for the extented portion
and shall interface with existing gird.
99 Lamu Price schedule
1 Item : 1.14
As per price schedule, it is
mentioned as " Post type
(400/Sq3)kV/(110/sq3)V
(phase‑to‑neutral) (1-Phase) 2-
winding capacitor voltage
transformers with 2 no. of Class
3P for protections and 1 no. of
Class 0.5 for instrument/BCU
with rated output 100VA per
phase (50VA for each winding) "
Since it is a 2 - winding CVT, 1
no. of class 3P and 1 no. of class
0.5 shall be provided. Please
confirm.
Correct.
100 Lamu Price schedule
1 Quantity
mismatch
As per price schedule 1 item 1.3
400kV Disconnector, motorised
(3-phase) 4000A complete with
one integral motorised earth
switch - 2 Nos
As per SLD
400kV Disconnector, motorised
(3-phase) 4000A complete with
one integral motorised earth
switch - 7 Nos
Please confirm the actual
requirement and update the price
schedule.
Refer to item 32.
25 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
101 Lamu Price schedule
1 Quantity
mismatch
As per price schedule 1 item 1.4
400kV Disconnector, motorised
(3-phase) 4000A complete with
two integral motorised earth
switches - 3 Nos
As per SLD
400kV Disconnector, motorised
(3-phase) 4000A complete with
two integral motorised earth
switches - 0 Nos
Please confirm the actual
requirement and update the
price schedule.
Refer to item 32.
102 Lamu Price schedule
1 Quantity
mismatch
As per price schedule 1 item 1.6
400kV Class 4 20kA (1-phase)
gapless zinc oxide surge
arresters with pressure relief
complete with surge counters and
current leakage meter - 12 Nos
As per SLD
400kV Class 4 20kA (1-phase)
gapless zinc oxide surge
arresters with pressure relief
complete with surge counters and
current leakage meter - 9 Nos
Please confirm the actual
requirement and update the
price schedule..
Refer to item 20.
103 Lamu Price schedule
1 Quantity
mismatch
As per price schedule 1 item 2.3
220kV Disconnector, motorised
(3-phase) 2000A complete with
two integral motorised earth
switches - 1 No
As per SLD
220kV Disconnector, motorised
(3-phase) 2000A complete with
two integral motorised earth
switches - 0 Nos
Please confirm the actual
requirement and update the
price schedule..
Refer to item 20.
26 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
104 Lamu Price schedule
1 Quantity
mismatch
As per price schedule 1 item 2.11
Post type (220/Ö3)kV/(110/Ö3)V
(phase‑to‑neutral) (1-Phase) 2-
winding capacitor voltage
transformers with 1 no. of Class
3P for protections and 1 no. of
Class 3P/1 for instrument/BCU
with rated output 100VA per
phase (50VA for each winding) -
3 Nos
As per SLD
Post type (220/Ö3)kV/(110/Ö3)V
(phase‑to‑neutral) (1-Phase) 2-
winding capacitor voltage
transformers with 1 no. of Class
3P for protections and 1 no. of
Class 3P/1 for instrument/BCU
with rated output 100VA per
phase (50VA for each winding) -
0 Nos
Please confirm the actual
requirement and update the
price schedule..
Refer to item 20.
27 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
105 Lamu Price schedule
1 Quantity
mismatch
As per price schedule 1 item 2.13
Post type combined current and
voltage transformer with 2 no. of
Class 0.2 CT cores per phase
with minimum rated output of 5VA
and with (220/Ö3)kV/(110/Ö3)V
(phase‑to‑neutral) (1-Phase) 2-
winding inductive voltage
transformers of Class 0.2 with
minimum 10VA per phase for
high accuracy metering - 3 Nos
As per SLD
Post type combined current and
voltage transformer with 2 no. of
Class 0.2 CT cores per phase
with minimum rated output of 5VA
and with (220/Ö3)kV/(110/Ö3)V
(phase‑to‑neutral) (1-Phase) 2-
winding inductive voltage
transformers of Class 0.2 with
minimum 10VA per phase for
high accuracy metering - 0 Nos
Please confirm the actual
requirement and update the
price schedule..
Refer to item 20.
106 Lamu Appendix D.2,
Schedule No.1,
Item No.5 , 5.2
KET-2014-D-
303 Lamu
400kV SLD
REV 2
Diameter 1:
Please confirm whether there is
an adequate space is available to
accommodate Tie CB Bay
Control unit in Diameter 1 Control
Panel
Yes.
107 Lamu Appendix D.2,
Schedule No.1,
Item No.5 , 5.4
KET-2014-D-
303 Lamu
400kV SLD
REV 2
Diameter 2:
Please confirm whether there is
an adequate space is available to
accommodate Reactor(SR2) CB
Bay Control unit in Diameter 2
Control Panel
Yes.
28 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
108 Lamu Appendix D.2,
Schedule No.1,
Item No.5 , 5.4
KET-2014-D-
303 Lamu
400kV SLD
REV 2
Diameter 3:
Please confirm whether there is
an adequate space is available to
accommodate Reactor(SR1) CB
Bay Control unit in Diameter 3
Control Panel
Yes.
109 Lamu General Please confirm that necessary
space provisions is available in
the control room to accommodate
the protection and control
cubicles.
Yes.
110 Lamu Lot C_Tech
Spec_Section
V,Clause 11,
LV service
equipment,
11.2, Scope of
works
Lot
C_Appendix
C.2_Schedule
of Technical
Particulars_La
mu 400kV Ext,
I. LV services
equipment, 1.
110V DC
system-
substation
services
supply.
As per the price schedule the
110V DC & 48 V DC qty are
mentioned as zero , we presume
that existing DC system is
sufficient to cater the requirement
of new bay extension & no DC
system is included in the bidders
scope.
Kindly confirm our understanding.
Correct.
111 Hindi General Please provide the altitude of
Hindi substation.
Approximately 220m.
112 Hindi Price schedule
1 Item 7.1
"Main earthing system for the
complete substation:- Substation
underground earthing system
with rating of 31.5kA, 1 Sec for
220kV."
We presume main earth mat is
already existing and 220kV
equipment earth risers alone
considered in present scope.
Please confirm.
Change of scope. Earthing would be only required for the
extented portion and shall interface with existing gird.
29 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
113 Hindi General Please confirm that necessary
space provisions is available in
the control room to accommodate
the protection and control
cubicles.
Yes.
114 Hindi
Price schedule
1 Quantity
mismatch
As per price schedule 1 item 2.10
220kV Post type current
transformer (1-phase) - 1 No
As per SLD
220kV Post type current
transformer (1-phase) - 3 Nos
Please confirm the actual
requirement and update the price
schedules 1 and 4 accordingly.
Change of scope. Price schedule revised and will be
uploaded as addendum.
115 Hindi Price schedule
1 Quantity
mismatch
As per price schedule 1 item 2.12
Post type (220/Ö3)kV/(110/Ö3)V
(phase‑to‑neutral) (1-Phase) ,
two winding inductive voltage
transformers Class 3P for
protections, and Class 0.5 for
instrument and bay computer with
rated output 150VA per phase
(50VA for each winding) for
busbar - 0 Nos
As per SLD
Post type (220/Ö3)kV/(110/Ö3)V
(phase‑to‑neutral) (1-Phase) ,
two winding inductive voltage
transformers Class 3P for
protections, and Class 0.5 for
instrument and bay computer with
rated output 150VA per phase
(50VA for each winding) for
busbar - 1 No
Please confirm the actual
requirement and update the price
schedules 1 and 4 accordingly.
Qty = 0. Price schedule revised and will be uploaded as
addendum.
116 Hindi General We presume that existing main
trenches for the proposed
extension bays are already
available. Only sub trenches
have to be provided. Please
confirm.
Extension of Main Trenches is required for the extension
works.
117 Hindi General Extension of LVAC, LVDC boards
is not in our scope. Please
confirm.
Extension on LVAC and LVDC shall be part of the scope
and the bidder upon contract award shall undertake a
study to determine the capacity of the existing system and
upgrade as necessary.
30 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
118 Hindi General No scope of works is envisaged
for the future equipments and
equipments supplied by others.
Please confirm.
Change of scope. The current scope includes interfacing
with existing equiment or plant supplied by others.
119 Hindi General We presume existing towers and
gantries are already present for
the extension of transformer and
reactor bays.
Change of scope. New gantry and towers shall be
supplied for the new extension bays. Revised price
schedule will be uploaded.
120 Hindi Price schedule
Item 2.15
Tubular busbar for isolator
connection to the busbar alone
shall be considered. Main busbar
tubes are not considered in
present scope. Please confirm.
Change of scope. Main busbars shall be extended.
Revised price schedule will be uploaded.
121 Hindi KET-2014-D-
302_Hindi
220kV Rev 1,
Existing busbar current rating is
1250A but the bay equipments
are rated for 2000A. Please
confirm the actual requirement.
Comply to requirements.
122 Hindi Price schedule
1 Item 2.12
As per price schedule
220kV busbar inductive voltage
transformer - 2 cores with 0.5 and
3P
As per SLD
220kV busbar inductive voltage
transformer - 2 cores with 3P/1.0
and 3P
Please confirm the actual
requirement.
The information shown in the tender is correct i.e. IVT is
existing and no requirement for new unit.
123 Hindi Lot
C_Appendix
C.3_Schedule
of Technical
Particulars_Hin
di 220kV Ext,
page 24 of 206
Current rating of all the
equipments in the extension bay
is considered as 2000A as per
technical datasheet. Please
confirm.
Refe to item no 121
124 Hindi General Please confirm that necessary
space provisions is available in
the control room to accommodate
the protection and control
cubicles.
Yes.
125 Lamu Lamu Price
schedule Sl. No
5.9
As per site visit, Lamu substation
is not yet constructed. Hence
please confirm the requirment of
Fault monitoring panel.
It is assumed that the Fault Monitoring System will be
supplied by others under a separate EPC contract.
Therefore for this tender the bidders shall include the
scope to extend and interface with the Fault Monitoring
System to include the new plant items as necessary.
126 Lamu Lamu Price
schedule Sl. No
12.5
Please confirm the requirement
of VT Fuse Box & if the same is
required, please furnish the
details.
Not clear what the bidder is seeking to clarify. However
the requirement is to provide a marshalling box with
isolatable fuse links.
31 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
127 Lamu Lamu Price
schedule Sl. No
5.11
Please note that the Price
schedule mentions 220kV
metering panel but 220kV
Combine CT/VT requirement is
not mentioned in price schedule.
Hence please confirm the CT/VT
connection details for this. The
usual practice followed by Kenya
is procurement of Combined
CT/VT.
Qty = 0. Price schedule revised and will be uploaded as
addendum.
128 Lamu Lamu Price
schedule Sl. No
5.5
Lot A is has 220kV line from
Lamu to Hindi substation but Lot
C Lamu price schedule doesn’t
mention 220kV Line protection
requirement. Hence please clarify
the requirement.
Change of scope. Revised price schedule and documents
will be uploaded.
129 Lamu Lamu Price
schedule Sl. No
11.1
Please furnish 90 MVA
transformer technical data sheet.
Technical schedule is provided under section J. The
transfomer shall be auto-transfomer. The tender drawing
show as 2 winding power transformer, this will be revised
and re-issued.
130 Lamu Lamu SLD As per site visit Lamu substation
is not yet constructed. Please
confirm the land develpment
scope of this substation.
This information shall be provided at a later stage.
131 SLD Please note that Hindi SLD has
220kV Bus VT,however same is
not mentioned in the price
schedule & not available at the
Site. Please confirm the
requirement.
Refer to item no. 122.
132 SLD As per site visit meeting , Ketraco
confirmed that the revised scope
includes 2 Nos 220kV line bay.
Please furnish revised SLD & the
revised Price schedule.
See item no. 128.
133 NE SLD Please note that the NE 400kV
SLD mentions Bus VT as 3 X
400/r3 but in the Price schedule
only 2nos are mentioned. Please
clarify the exact requirement
See item no. 61.
134 NE SLD Please note that in the SLD the
transformer quantity is 4nos & in
the price schedule 3nos are
mentioned. Please clarify the
exact requirement
See item no. 43.
32 of 33
Employer : The Kenya Electricity Transmission Company Ltd 22.07.2015
Invitation to Bid No KETRACO/PT/010A,B&C/2015 – Lot A,B&C
Sr.
No.Ref Clause / Page Description Bidders Query KETRACO response
Design, Manufacture, test, Supply and Installation of 400 kV TRANSMISSION PROJECT
Clarification Lot C Technical List No.01
135 Altitude As per specification NE
substation altitude is 1600
Meters. In GTP already BIL
values are corrected for 1600
mm altitude.Hence please clarify
whether the offered equipment's
shall be as per GTP.
Yes.
136 Cl. 4.3.1.1 Please clarify the contacts for
Isolator whether copper or
Aluminium
The technical specifications has made references to
relevant IEC standards, and therefore the bidders shall
refer to the standards and comply accordingly.
137 SC Type test Please note that we shall furnish
relevant Type test reports only for
the CB,CT,VT,LA,Disconnector &
Earth switch. Please confirm the
short circuit test requirement.
Please read the tender requirements and fullfill all the
required criteria.
138 Cl 14.7.2 Please furnish the data of the
existing Transformer for parallel
operation
This will be only provided upon contract award and design
review.
139 Cl.15.6.14 Please clarify the galvanising
thickness requirement
The technical specifications has made references to
relevant IEC/International standards, and therefore the
bidders shall refer to the standards and comply
accordingly.
140 Cl 15.2.4 Please clarify whether Tank
construction is conventional or
bolted type for shunt Reactor
For the purpose of the tender all bidders shall offer bolted
type.
141 Design and
Engineering
4.4.2
Please let us know within how
many days notice has to be
issued
Not clear what the bidder is seeking to clarify.
33 of 33