ACTIVITY
1 SUPPLY VOLTAGE FROM GENERATOR, UTILITY OR ANY POWER SOURCE
a) Measure the supply voltage Generator/Utility
COMMENTS
VOLTAGES
Red – Yellow (White)
Red – Blue
Red – Earth (Green)
Red – Neutral (Black)
Yellow – Blue
Yellow – Earth (Green)
Yellow – Black (neutral)
Blue – Earth (Green)
Blue – Black (neutral)
SUPPLY CABLE TO DISTRIBUTION BOARD
a) Visual inspection of Supply Cable from Utility, Generator or any
Power Source to the Distribution Board to inspect for damage to
cable Insulation
b) Test Supply Cable (insulation Resistance Test)
INSULATION RESISTANCE RESULTS:
Red – Yellow (White)
Red – Blue
Red – Earth (Green)
2
Red – Neutral (Black)
Yellow – Blue
Yellow – Earth (Green)
Yellow – Black (neutral)
Blue – Earth (Green)
Blue – Black (neutral)
3 DISTRIBUTION BOARD (Before Energizing)
General Checks
a) Condition or damage
b) Signs of Insects
c) Combustible Materials
d) General Cleanliness
e) Presence of Drawings and Legend
f) The Distribution Board should have covers to prevent access to live
Parts such as Busbars, Cable Connections to breakers
BUSBARS
Check condition of busbars especially for
a) Discoloration from heating
b) Damaged or loose busbar support insulation
c) Deformation
d) Adequate support
e) Check all neutral and earth bar links
f) Busbars should always be covered
g) Installed busbars should always be staggered
h) Cables connected to busbars should be properly crimped and lugs
used should be of the correct size; washers should be used were
necessary to ensure maximum contact of busbars and lugs
Circuit breakers, fuses contactors, switches and other components
a) Ensure correct torquing on main breaker of supply & distribution
Cables, they should be tightly and correctly bolted.
b) Flash Barriers should be available on main breaker
c) Components should have correct voltage rating and ISC (short Circuit
rating)
d) Cables connected to breakers, contactors or any component in
Distribution Board should be correctly stripped and tightly
connected (Check tightness of all wiring connections)
e) Lugs to cables should be properly crimped with a crimping tool and
lugs should be of the correct size
f) Earth Leakage should always be installed as well as surge protection
within the distribution board
BUILDING INSPECTION
Before Distribution Board is Energized
a) Check Building wiring, there should be no visible cables protruding
from ceiling, socket outlets and switch outlets i.e., all socket outlets,
switch outlets, fittings should be installed before energizing
Distribution Board.
b) All socket outlets should have a Red Phase (Live wire), Neutral Phase
and Earth Phase all the above (Red i.e., live, Neutral & Earth) should
be properly connected to the correct terminals of the socket outlet.
c) The Red Phase i.e., Live Wire, should be the red Phase (i.e., Hot
wire), the Neutral wire and the Earth wire SHOULD NEVER BE
CONNECTED (BONDED TOGETHER AT ANY POINT)
d) Cables connected to Socket Outlets, switches and fittings should
always be stripped correctly and tightly connected
e) Conduits installed in the ceiling should be connected properly with
connectors and 90 degrees bends, neatly bolded down with saddles,
installed conduits should not have cracks or holes least water sips
into the conduits
EARTHING
a) Connection of Earthing to Distribution Board from main earthing
should be checked for continuity and firmness
b) Earthing within the distribution board should be separate from
neutral, no Bonding between Earthing and Neutral i.e., no
connection between earthing and neutral within Distribution Board
TESTS TO BE DONE
a) Earth Continuity Tests
b) Wiring continuity tests (distribution Board cables, building cables
and supply cables
ENERGIZING DISTRIBUTION BOARD
a) After the above inspections have been done; turn on the main
breaker in the Distribution Board and measure the voltage between
the phases and the neutral, measurement should be from the
busbars.
VOLTAGES
Red – Yellow (White)
Red – Blue
Red – Earth (Green)
Red – Neutral (Black)
Yellow – Blue
Yellow – Earth (Green)
Yellow – Black (neutral)
Blue – Earth (Green)
Blue – Black (neutral)
FINAL TEST TO BE DONE WHEN DISTRIBUTION BOARD IS ENERGIZED
a) Earth Leakage Test