Mitsubishi Electric C Series Handling And Maintenance page 33

Condition 2: (Power line and grounded line)
(i) Connect FG terminal of MDU to PE terminal of MDU (panel) holder plate.
Make the earthing point (to be grounded to the earth) near MDU.
PE terminal shall be grounded to this point with as short wire as possible.
PE terminal effects to reduce the noise of MDU and to shut down the external noise.
The grounded wire impedance shall be low.
(ii) Shielded cable earthing
(a) When CC-Link cable or power supply cable of MDU are wired from the panel board, use the shielded cable and
ground to the earth near the way out.
Secure earthing reduces electromagnetic induction and high frequency noise.
(b) Remove the paint around grounded area to reduce the electrical contact impedance.
Metallic clamp is recommended.
• For further details, please read "MELSEC CPU user's manual" regarding to the wire and cable connection method to PLC.
2 2 2 Measurement of insulation resistance and withstand voltage test 2 2
• Voltage transformers are conncted between the poles on the load side of the circuit breaker.
(i) Measurement of insulation resistance
A 1000 volt insulation resistance tester cannot be used with a marks in the table as below.
A 500 volt insulation resistance tester shall be used, but measured resistance shows low resistance.
(ii) Withstand voltage test
Voltage shall not be applied at the portions with X marks in the table as below.
• The voltage between each terminal must not become DC5V or more when you do the cable check etc. of DA, DB, DG, SLD,
and the terminal FG for the CC-Link. It is likely to break down.
Measuring point/test
State of handle
Between live part and earth (except MDU terminal)
Line side
Between
different
poles
Load side
Between line and load terminal
Between main circuit and MDU terminal (L1, L2)
Between main circuit and MDU terminal (113, 114, FG)
(With electric energy accumulated pulse output option)
Between main circuit and MDU terminal (DA, DB, DG, SLD, FG)
(With CC-Link option)
Between MDU terminal (L1, L2) and MDU terminal (FG)
Between MDU terminal (L1, L2) and MDU terminal (113, 114, FG)
(With electric energy accumulated pulse output option)
Between MDU terminal (L1, L2) and MDU terminal (DA, DB, DG, SLD, FG)
(With CC-Link option)(Note3.)(Note4.)
Note1. Connect MDU terminal (L1, L2, 113, 114, DA, DB, DG, SLD and FG) to the earth side.
Note2. Connect MDU terminal (113, 114, DA, DB, DG, SLD and FG) to the earth side.
Note3. Do not test between MDU terminal (DA, DB, DG and SLD) and MDU terminal (FG).
Note4. Connect each MDU terminals (DA, DB, DG, SLD, FG) before you start the test.
31
Shield
Paint masked
CAUTION
Between left and middle poles
Between middle and right poles
Between left and right poles
Between middle and neutral poles
Between left and middle poles
Between middle and right poles
Between left and right poles
Between middle and neutral poles
Screw
Metallic clamp
Shielded cable
Measurement of
Insulation resistance
ON OFF
Withstand voltage test
ON OFF Test condition
AC2500V 1min

In the case of
these tests,

Do not connect

MDU terminal

to live part or
erath
AC2500V 1min
(Note1.)
AC1500V 1min
(Note2.)



