11 CHECKING ELETRICAL COMPONENTS
11-1 Measurement of Insulation Resistance
The insulation is in good condition if the resistance exceeds 1 MOhm
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) Unit
Clamp an alluminium plate fin or copper tube with
the lead clip of the insulation resistance tester and
measure the resistance by placing a probe on N terminal,
and then on Lterminal the terminal plate (fig.2)
c) Measurement of Insulation Resistance
for Electrical Parts
Disconnect the lead wires of the disired electric
part from terminal plate, PCB assy, capacitor, etc.
Similary disconnect the connector. Then measure
the insulation resistance (fig.1 to 4).
Refer to electric wiring diagram.
NOTE
If the probe cannot enter the poles because the hole is too narrow
then use a probe with a thinner pin.
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