11. CHECKING ELECTRICAL COMPONENTS
11-1. Measurement of Insulation Resistance
●The insulation is in good condition if the resistance exceeds 1MΩ .
11-1-1. Power supply cord
Clamp the grounding wire of power cord with the lead clip of the insulation resistance tester and measure the resistance by placing a probe on either of the two power wires. (Fig. 1)
Then also measure the resistance between the grounding and other power terminals. (Fig. 1)
11-1-2. Indoor unit
Clamp an aluminum plate fin or copper tube with the lead clip of the insulation resistance tester and mea- sure the resistance by placing a probe on each termi- nal screw where power supply lines are connected on the terminal plate. (Fig. 2)
Ground wire
Clip
Probe
Insulation tester
Fig. 1
Terminal plate
Probe
Clip
11-1-3. Outdoor unit
Clamp an aluminum plate fin or copper tube with the lead clip of the insulation resistance tester and mea- sure the resistance by placing a probe on each termi- nal screw on the terminal plate. (Fig. 2)
Note that the ground line terminal should be skipped for the check.
Disconnect the lead wires of the desired electric part from terminal plate, capacitor, etc. Similarly discon- nect the connector. Then measure the insulation resistance. (Figs. 3 and 4)
NOTE
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.
Copper | Insulation |
tube or | tester |
metallic part |
|
Fig. 2
Probe
Clip
Copper tube or metallic part
Insulation tester
Fig. 3
From fan motor, compressor and other parts
Metallic | Probe |
part |
|
Clip |
|
Insulation tester
Fig. 4
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