Trouble Detection And Solution - Hitachi CMU Series User Manual

6 MAINTENANCE

6.2.2 Trouble detection and solution

(1) Is the cabling correctly?
Check cables for disconnection or incorrect connection.
(2) Are the modules mounted correctly?
Check that no set screws loosen.
(3) Is grounding done properly?
• Do not ground the CMU module in the
same place where high-voltage equipment
is grounded. They must be grounded in
separate places.
• Perform grounding work conforming to
Class D grounding or higher.
(4) Are LG and FG separated?
• Be sure to separate the LG from the FG
or vice versa because power noise enters
the FG via the LG. Failure to observe
this rule may result in an equipment
malfunction.
• Ground the LG at the power supply side.
LG is here.
FG is over there.
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