FIRST FLOOR

Cable Rating:

Standard applications Number Cable specification (mm2 c.s.a.)

Current carrying in

conduit

Voltage drop (mV/amp/m)

Lighting 14 1 13 44Radial sockets (13amp) 15 4 30 11Shower(17m) 1 10 52 4.4

Lighting:

Location Cable Length WattsTerrance 4 60Bath 3 60Master Bath 4 60Bedroom 1 11 60Bedroom 2 15 60Master Bedroom 15 60Dining Room 13 60Staircase 2 58

Remarks Cable c.s.a (mm2) Minimum overload protection (amps)- For max. 50m2 floor area 21m cable

Master Bedroom 2..5 20- For max. 20m2 floor area 17m cable

Terrance, Bath, Master Bath, Bedroom 1, Bedroom 2, Dining Room and Staircase

4.0 30

Switches and sockets 1.2m from finishes floor level. Sockets and switches height is :

H=2.7-1.2 =1.5m

Calculation Part:

For 58 watts lighting:

Amps = Watts ÷ Volts = 58 ÷ 240 = 0.24From table, select 1 mm2 c.s.a.

Staircase:

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = (44 x 0.24 x 2.0) ÷ 1000 = 0.021 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 1 mm2 c.s.a. cable is satisfactory.

For 60 watts lighting:

Amps = Watts ÷ Volts = 60 ÷ 240 = 0.25From table, select 1 mm2 c.s.a.

Terrance:

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = (44 x 0.25 x 4.0) ÷ 1000 = 0.044 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 1 mm2 c.s.a. cable is satisfactory.

Bath:

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = (44 x 0.25 x 3.0) ÷ 1000 = 0.033 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 1 mm2 c.s.a. cable is satisfactory.

Master Bath:

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = (44 x 0.25 x 4.0) ÷ 1000 = 0.044 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 1 mm2 c.s.a. cable is satisfactory.

Bedroom 1:

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = (44 x 0.25 x 11.0) ÷ 1000 = 0.121 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 1 mm2 c.s.a. cable is satisfactory.

Bedroom 2:

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = (44 x 0.25 x 15.0) ÷ 1000 = 0.165 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 1 mm2 c.s.a. cable is satisfactory.

Master Bedroom:

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = (44 x 0.25 x 15.0) ÷ 1000 = 0.165 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 1 mm2 c.s.a. cable is satisfactory.

Dining Room:

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = (44 x 0.25 x 2.0) ÷ 1000 = 0.022 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 1 mm2 c.s.a. cable is satisfactory.

Shower

Shower specification

For Master Bath: Shower rating (kW) = 8.4Cable length (m) = 5.0mFuse of MCB rating (amps) = 40

Amps = Watts ÷ Volts = 8400 ÷ 240 = 35

From table, select 10 mm2 c.s.a. (52 amps)

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = ( 4.4 x 35 x 5.0 ) ÷ 1000 = 0.77 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 10 mm2 c.s.a. cable is satisfactory.

For Bath:

Shower rating (kW) = 8.4Cable length (m) = 3.0mFuse of MCB rating (amps) = 40

Amps = Watts ÷ Volts = 8400 ÷ 240 = 35

From table, select 10 mm2 c.s.a. (52 amps)

Voltage drop = (mV x Current flowing x Cable length) ÷ 1000 = ( 4.4 x 35 x 3.0 ) ÷ 1000 = 0.462 volts

Maximum voltage drop = 240 x 4% = 9.6 volts.

Therefore, 10 mm2 c.s.a. cable is satisfactory.

Lighting 14 1 13 44Radial sockets 15 4 30 11Shower 1 10 52 4.4

Diversity

Standard of Diversity Factor

Appliance / Circuit Diversity factorLighting 66% of the total current demandRadial sockets 100% of the largest circuit full load current + 40% of the remainderShower 100% of highest rated + 100% of second highest + 25% of any remaining

Diversity for Domestic Installation

Appliance / Circuit Number of appliance / Circuit Current Demand (amps) Diversity Allowance (amps)Lighting 8 13 8 x 13 x 66% = 84.48Double insulated shaver sockets 2 30 2 x 30 x 100% = 60Radial sockets 2 - 15 22 30 22 x 30 x 40% = 264Shower 2 52 2 x 52 x 100% = 104

Total = 512.48 amps