49
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 grounding terminal of the power plug with a
lead clip of the insulation resistance tester and
measure the resistance by placing a probe on either of
the two power terminals. (Fig. 1)
Then, also measure the resistance between the
grounding and other power terminals. (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 where power supply lines are
connected on the terminal plate. (Fig. 2)
10-1-3. Outdoor 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.
10-1-4. 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
Ground
power plug
(Local supply)
probe
Insulation
tester
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
The shape of the power plug may differ from
that of the air conditioner which you are
servicing.
NOTE
