Power Supply And Wiring - LG LP-E5020CL Service Manual

6.6 Power Supply and Wiring

The unit is completely wired internally at the factory
according to general rule of electrical technology, but
local rules, if they are required, should be complied
with.
1) Power supply
Power source must fulfill the following conditions:
¤ The working voltage should be higher than 90%
and lower than 110% of the rated voltage marked
on the name plate.
¤Ł The working voltage among the three phases
should be balanced with in a 3% deviation from
each phase voltage.
¤ØThe starting voltage should be higher than 85% of
the rated voltage marked on the name plate.
Voltage
Power soure voltage
working voltage
Starting voltage
2) Wiring
After the confirmation of the above conditions,
prepare the wiring as follows:
¤ Never fail to have an individual power specialized
for the air conditioner. As for the method of wiring,
be guided by the circuit diagram pasted on the
inside of control box cover.
¤Ł Provide a circuit brake switch between power
source and the unit.
¤ØThe screws which fasten the wiring in the casing of
electrical fittings are liable to come loose from
vibrations to which the unit is subjected during the
course of transportation. Check them and make
sure that they are all tightly fastened.
(If they are loose, it could give rise to burn-out of
the wires.)
¤ŒSpecification of power source.
¤ºConfirm that electrical capacity is sufficient.
¤ See to that the starting voltaged is maintained at
more than 90 percent of the rated voltage marked
on the name plate.
¤ Confirm that the cable thickness is as specified in
the power sources specification.
(Particularly note the relation between cable length
Starting point
Time
and thickness.)
¤ Never fail to equip a leakage brake where it is wet
or moist.
¤ The following troubles would be caused by voltage
drop-down.
• Vibration of a magnetic switch, damage on the
contact point there of, fuse breaking, disturbance to
the normal function of a overload protection device.
• Proper starting power is not given to the compressor.
3) Earthing work
Connect the cable of diameter 1.6mm or more to the
earthing terminal provided in the control box and do
earthing. In case of equipping the electrical resis-
tance will be reduced to 500Ω. But in case that no
earthing is required in particular, the electrical resis-
tance between the med is below 100Ω.
Also, the unit can be earthed to the water service
pipe buried under the ground where electrical resis-
tance of 3Ω or less is retained. Of course, the earth-
ing to pipes must be approved by the authority of
water supply.
Indoor
Outdoor
Earthing
– 32 –
Earthing
Knife Switch
Leakage
brake
Main cables