30
10-1. Measurement of Insulation
Resistance
●
The insulation is in good condition if the resistance
exceeds 2M
Ω
.
10-1-1. Power Supply Wires
Clamp the ground wire of the power supply wires with
the lead clip of the insulation resistance tester and
measure 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)
10-1-2. 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 on the terminal plate. (Fig. 2)
Note that the ground line terminal should be skipped
for the check.
10-1-3. 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)
10-1-4. 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. 3 and 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.
NOTE
10. CHECKING ELECTRICAL COMPONENTS
Insulation
tester
Probe
Clip
Ground wire
Terminal plate
Copper
tube or
metallic part
Clip
Insulation
tester
Probe
Copper
tube or
metallic part
Clip
Insulation
tester
Probe
Clip
Insulation
tester
Probe
Metallic
part
From fan motor,
compressor and
other parts
Fig. 1
Fig. 2
Fig. 3
Fig. 4
