La Marche A75M Instruction - page 10
INSTRUCTION / TROUBLESHOOTING MANUAL FOR MODEL A75M
PAGE 10 OF 13
NOTE: Blown printed circuit boards, fuses or loose printed circuit boards fuses could cause an out of phase
condition. (Blowing AC input fuses) If a blown printed circuit board fuse is found, a wire on the gate lead of
the SCR/Diode module could be disconnected or a defective SCR/Diode module could exist.
Problem: Blown DC fuse.
1.
Make sure the correct type of fuse is being used.
2.
Check all connections to DC fuse to be certain they are tight.
3.
Check polarity of output cables, output connector, SCR/Diodes module and diode SD4 for shorts.
Problem: Blown control transformer fuse CTF.
1.
Defective contactor (shorted coil)
2.
Control taps set wrong on control transformer H1 - H2.
3.
Defective control transformer.
Problem: Control Transformer Fuses blown.
1.
Defective S2A-320 Drive Board.
2.
Shorted MOV. (Metal Oxide Varistor)
NOTE: Voltage across secondary of control transformer:
X1 - X2 = 120Vac.
Problem: Complete "ON" but battery not charged.
1.
Record all readings on digital display board before disconnecting battery. Check status of complete
light.
2.
Check battery for defective cells.
3.
Call local La Marche Representative or factory for additional information.
4.
Possible settings on the S2A-320 control board.
Problem: Contactor does not pull in.
1.
Check AC input voltage and fuses.
2.
Check DC voltage at DC output terminals (battery connected).
3.
Check AC voltage output on control transformer.
4.
If 120 Vac. is present at AC contactor coil, contactor may be defective.
Problem: Failure light on CODE 0001 OR 0002.
1.
Check AC input voltage must be present.
2.
Check taps on power and control transformer.
3.
Check AC contactor.
4.
Check voltages on the secondary side of the control transformer.
5.
Loose connections on the control transformer.
6.
Check voltages on the S2A-243 transformer board.