LARSEN & TOUBRO LIMITEDLARSEN & TOUBRO LIMITED

Availability Based Availability Based Tariff MeterTariff Meter

Features of ABT MeterFeatures of ABT Meter• The Meter measures Active/Reactive energy on 3

phase, 4 wire principle,• Computes the active energy import /export from the

substation bus bars during each successive 15 minutes block and stores it in its Memory.

• Integrates the reactive energy algebraically into two separate registers,

A) One for the period for which the average RMS

voltage is 103% or higher (High VARh), B) The other for the period for which the average RMS voltage is below 97.0% or lower (Low VARH).

Features of ABT MeterFeatures of ABT Meter• Average frequency for each successive 15-min

block, as a 2-digit code Original Frequency = 49 + 0.02*2-digit code.

• Net Wh transmitted during each successive 15-minute block, upto second decimal, with plus/minus sign

• Cumulative Wh transmitted at each midnight, in six digits including one decimal

• Cumulative VARh transmitted for voltage high condition, at each midnight in six digits including one decimal

Features of ABT MeterFeatures of ABT Meter

• Cumulative VARh transmittal for voltage low condition, at each midnight, in six digits including one decimal

• Date and time blocks of failure of VT supply on any phase, as a star (*) mark

• The meters shall store all the listed data in their memories for a period of ten days

• Battery back-up for data viewing display.Battery back-up for data viewing display.

Basic Technical SpecificationsBasic Technical Specifications

• . Accuracy Class : 0.2• INTERFACE : WITH RS485

• Reference Voltage(Vref) : 110V.(P-P) • Rated Current ( Ib) : 5A or 1A.• Operating Voltage :+20% to -30% of

Vref.• Operating Current : 0.2% to 200% of Ib

Display ListDisplay List i) Meter Serial No :NP5001A

ii) Date (year month day) :081112 d iii) Time ( hour min. sec. ) :151030 t iv) Cumulative Wh reading :12345.6 C v) Average frequency of the last block :49.89 F vi) Net Wh transmitted in last block :28.75 E vii) Average % voltage :99.2 U viii) Reactive power (VAR) :106.5 r ix) Voltage - high VARh register reading :01234.5 H x) Voltage - low VARh register reading :00123.4 L xi) Low battery indication

LARSEN & TOUBRO LIMITEDLARSEN & TOUBRO LIMITED

Data Collecting Data Collecting DeviceDevice

DCD Main WindowDCD Main Window

(D) COLL. SELECTED DATA

(U) PC COMMUNICATION

(P) PROGRAMMING MODE

(O) MEMORY STATUS CHECK

(R) ACCURACY

Data Collecting DeviceData Collecting Device

1. Press (D) for Collecting of Meter Dada

2. Press (U) for damping the data from DCD to PC

3. Press (P) for enter into Programming Mode i.e only for time adjustment for 1 minute

4. Press (O) for Memory status check

Time adjustment through DCDTime adjustment through DCD

After connecting the Optical Port to the meter and DCD following step to be done for Time adjustment.

1. Press “P” in DCD to enter in Programming mode.

2. Enter the Password: XMISSION

Time adjustment through DCDTime adjustment through DCD

3. Press Enter after typing the “XMISSION” in DCD

4. Following Manu will come after pressing enter in DCD :

(A) Advance

(R) Retard

(X) back to Manu

Time adjustment through DCDTime adjustment through DCD

5. i) Press “A” if the meter time is slow

ii) Press “R” if the meter time is fast

N.B :

i) Program/ time adjustment (only for 1 minute) can be done one in a week.

ii) Time taken to adjustment one min. 1 hrs. 30 min i.e. 6 Blocks

iii) Time adjustment can be done only on power On conditions

Do’s & Don'ts with DCDDo’s & Don'ts with DCD

1. Don’t keep the DCD in Suspended mode

2. To save the battery life switch off the DCD properly

3. DCD battery should be charged at least twice in a week

4. Charging time is 3 hours

RS485 Network

• Serial Port, Local Area Communication

– Two-wire, multidropping– Uncomplicated hardware– No distance limitation within a premises

Hardware Required• We have used IEC 1107 protocol for RS 485 communication. • Recommended hardware is mentioned below :

1. Twisted pair with foil shielding and a drain wireMake : Belden ( Product Code 9841/8162/9501) cost Rs. 49,000 per 305m or equivalent local cable cost Rs. 2,000 per 100m.Characteristic Impedance : 120 OhmsTwist/Feet : 10

2. RS 485 to RS 232 Converter Make : Moxa Model No : Transio A53

3. PSTN Modem : Used for data transfer on PSTN Line from S/S to LDC

Make : Multitech 33.6 Kbps Model No : MT2834ZDXB

The System

Collection PointCollection Point

RS232RS232

RS232 to RS232 to RS485 RS485 ConverterConverter

MeterMeter

D+D+

D-D-