46
14-1. Measurement of Insulation
Resistance
●
The insulation is in good condition if the resistance
exceeds 2M
Ω
.
14-1-1. Power Supply Wires
Clamp the ground wire of the power supply wires with
the lead clip of the insulation resistance tester and mea-
sure the resistance by placing a probe on either of the
power wires. (Fig. 1)
Then measure the resistance between the ground wire
and the other power wire. (Fig. 1)
14-1-2. Indoor Unit
Clamp an aluminum plate fin or copper tube with the lead
clip of the insulation resistance tester and measure the
resistance by placing a probe on each terminal screw
except where the ground line is connected on the termi-
nal plate. (Fig. 2)
14-1-3. Outdoor Unit
Clamp a metallic part of the unit with the lead clip of the
insulation resistance tester and measure the resistance
by placing a probe on each terminal screw where power
supply lines are connected on the terminal plate. (Fig. 2)
14-1-4. Measurement of Insulation
Resistance for Electrical Parts
Disconnect the lead wires of the desired electric part
from terminal plate, capacitor, etc. Similarly disconnect
the connector. Then measure the insulation resistance.
(Figs. 1 to 4)
Refer to Electric Wiring Diagram.
If the probe cannot enter the poles because the hole is
too narrow then use a probe with a thinner pin.
Insulation
tester
Probe
Clip
Ground wire
Fig. 1
Terminal plate
Copper
tube or
metallic part
Clip
Insulation
tester
Probe
Fig. 2
Copper
tube or
metallic part
Clip
Insulation
tester
Probe
Fig. 3
Clip
Insulation
tester
Probe
Metallic
part
From fan motor,
compressor and
other parts
Fig. 4
14. CHECKING ELECTRICAL COMPONENTS
NOTE
