Service manual

54
1)Measurement of Insulation Resistance
• The insuration is in good condition if the resistance
exceeds 1 MΩ.
(a)Power Supply Wires
Clamp the earthed 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
earthed wire and the other power wires (Fig. 1).
(b)Indoor Unit
Clamp an aluminium plate fin or copper tube with
the lead clip of the insulation resistance tester
and measure the resistance by placing a probe
on ➀, and then ➁on the terminal plate (Fig. 2).
(c)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 ➀, and then
➁on the terminal plate (Fig. 2).
(d)Measurement of Insulation Resistance for
Electrical Parts
Disconnect the lead wires of the disired electric
part from terminal plate, PCB Ass’y, capacitor,
etc.
Similarly disconnect the connector. Then
measure the insuration resistance. (Fig. 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.
NOTE
QP
CHECKING ELECTRICAL COMPONENTS