User Manual 990-9178A
DC MX06 40A Shelf Page 43 of 44 18th FEB 02
7 Fault Finding / Symptoms
The sub-system is designed for maximum reliability and therefore faults during normal operation are
unlikely. If faulty operation does occur the source of the failure can usually be readily determined by
inspection of the LED meter and the LED’s.
7.1 Warnings
POTENTIALLY LETHAL VOLTAGES AND SOURCES OF HIGH ENERGY ARE PRESENT WITHIN THE
POWER SYSTEM. EXTREME CAUTION MUST BE OBSERVED AT ALL TIMES. ACCESS TO THE
INTERIOR OF THE SYSTEM FOR INSTALLATION, COMMISSIONING, MAINTENANCE AND
REMOVAL AND REPLACEMENT PURPOSES IS LIMITED TO FULLY TRAINED SERVICE
PERSONNEL ONLY.
RINGS, WATCHES AND JEWELLERY SHOULD BE REMOVED AND ONLY SINGLE ENDED
INSULATED TOOLS SHOULD BE USED WHEN WORKING OR MAKING MEASUREMENTS INSIDE
THE SYSTEM. A SOLDERING IRON MUST NOT BE USED UNLESS THE INPUT, OUTPUT AND
BATTERY (IF CONNECTED) HAVE FIRST BEEN ISOLATED.
7.2 Fault Symptoms
Typical fault symptoms and their possible causes are shown in table below. If the fault cannot be
diagnosed contact the manufacturer.
SYMPTOM POSSIBLE CAUSE(S)
Output voltage is zero at load 1. Failure of AC supply.
2. Distribution device(s) tripped (check dist trip LED).
3. Failure of external disconnect device.
All Rectifiers Input Healthy LED’s are lit (4 LED
rectifiers) or Rectifier Fail LED not lit (single
LED Rectifier) but system bus voltage is zero
(LED display extinguished).
1. Rectifiers have tripped due to over-voltage.
2. System output not enabled, could be set to remote
enable instead of local enable. (see section 2.5.4)
One or more rectifiers “output healthy” LED is
extinguished temporarily (4 LED rectifiers). Or
one or more “Rectifier Fail” LED lit temporarily
(single LED Rectifier).
1. Rectifiers tripping due to over temperature condition,
(Local ambient may be above rated level). (see section
2.1.1)
One or more rectifiers output healthy LED
extinguished (4 LED rectifiers). Or one or more
“Rectifier Fail” LED lit (single LED Rectifier).
1. System in overload condition (check current limit
LED’s).
2. System tripped due to over-voltage condition (check
rectifier over-voltage LED’s).
Battery String not connected to system. 1. Battery connection switch set to “off”.
2. Battery connection switch set to “auto” and battery
string voltage below LVD level (see section 4.4.2)
3. System output voltage is below low voltage reconnect
level.
Battery string doesn’t disconnect when voltage
drops below LVD level.
1. Battery disconnect switch set to “on” instead of “auto”
(see section 4.4.2)