User manual

Maintenance 51
Emerson Energy Systems MFA150 Power System  NT6C28C User Manual
Table 30 – Fault diagnosis ( continued )
Fault symptom Possible causes
Failure to generate an
RFA alarm under
appropriate conditions
 Faulty rectifier
 Faulty wiring
 Faulty RFA MIN or RFA MAJ LED
Rectifiers are not sharing
the load
 Incorrect float or equalize adjustment on one or
more of the rectifiers
 Sense leads are open on one or more rectifiers
 Share mode incorrectly set on one or more
rectifiers
LVD contactor does not
reconnect the load
 Incorrect LVR or LVDR threshold setting
 Faulty controller card or RPM1000C
 Blown F1 fuse on the controller
(NT6C14GA/GB/GM and NT6C14GE/GF/GP) or
LVD (NT6C14GC/GD/GN and
NT6C14GG/GH/GQ) card
 Faulty contactor
On NT6C14GA/GM and NT6C14GP control and distribution panels only:
LV ALM lamp is lit  Low discharge voltage condition
 Incorrect LV level adjustment
TST BYPASS lamp is lit The NORMAL/BYPASS switch is in the BYPASS
position on the controller card.
On NT6C14GC/GN control and distribution panels only:
UNIT lamp is lit red Failure of the RPM1000C
UNIT lamp is flashing Low voltage on the memory back-up battery of the
RPM1000C
AC lamp is lit AC supply for the rectifiers has failed.
FLOAT lamp is lit yellow  Slightly high or low discharge voltage condition
 Incorrect HF or LF level adjustment
 Incorrect float or equalize level adjustment on
one or more rectifiers
FLOAT lamp is lit red  High or low discharge voltage condition
 Incorrect HV or LV level adjustment
 Incorrect float or equalize level adjustment on
one or more rectifiers
BOD lamp is lit  Low discharge voltage condition
 Incorrect BOD level adjustment
 Incorrect float or equalize level adjustment on
one or more rectifiers
HVSD lamp is lit  A high voltage shutdown signal was sent to the
rectifiers by the RPM1000C
 Incorrect HVSD level adjustment
FAN lamp lit Fan failure on one or more rectifiers
AUX lamp lit Auxiliary equipment failure (when programmed)
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