INSTALLATION, OPERATING AND TROUBLESHOOTING INSTRUCTIONS FOR MODEL A75D / A75DE –
THREE PHASE
Page 17 of 20
TROUBLE SHOOTING
Troubleshooting should be performed only by trained service personnel or experienced electricians.
CAUTION: Hazardous AC and DC voltages are present within the rectifier cabinet.
EQUIPMENT:
The only equipment required is a multimeter for voltage or resistance readings and analog ohmmeter
GENERAL INSPECTION
On servicing new equipment, before setting up any complicated testing or jumping to any conclusions,
give the unit a general inspection.
Check the following:
1.
Check DC output cables, connections, battery type, and number of battery cells with rectifier rating.
2.
Check unit specifications with customer order.
3.
Check input connections, input voltage and line breaker size.
4.
Check for shipping damage, loose connections, broken wires, etc.
5.
Certain failures can be caused by defective batteries and customer loads; make sure batteries and
loads are free from defects.
NOTE
: If the problem is found to be located in the printed circuit boards, the board should be replaced.
No attempt should be made to repair circuit boards in the field.
SERVICE INFORMATION
Information you should have when calling in for troubleshooting assistance:
1.
Equipment model number and serial number.
2.
The actual AC input voltage.
3.
The DC output voltage with and without the battery.
4.
Result of the check of AC breaker and DC output fuse.
5.
The actual DC output current and voltage when measured with battery and load connected to
rectifier.
SYMPTOMS & CAUSES
A.C Breaker Trips
Possible Cause:
1.
Wrong AC input voltage.
2.
An AC to DC short or AC or DC short to ground (see ground short circuit test).
3.
High DC output voltage.
Check battery voltage for proper number of cells.
Check control fuse on alarm interface board.
Float/Equalize voltage potentiometers not set properly. (See Float/Equalize adjustment
procedure for proper voltage setting.)
4.
Check for shorted SCR’s.
