Ups Fails To Backup When Blackout - Ablerex 3 MS series User Manual

5.4 UPS Fails to Backup When Blackout

Check Items
Battery is weak and no battery
charging current
When it is in charging mode.
Battery is defective
Battery harness is loose in
connection.
The IC of DC Booster stage is
out of order.
DC to DC converter
abnormal and/or the battery
fuse is defective.
FIG. 5.4
Trouble-shooting
Remove the harness of the battery from the
control board to measure the battery voltage. If
the voltage drops dramatically, please use a
switching power supply to charge the battery.
The charging voltage can be set at 86.4Vdc.
The battery shall be charged up to 80% of its
capacity.
Replace the battery with same size.
The current provided by the battery is approx. 20-30A when it is at full
load.
Please proceed to check any loose connection.
1.Check the related circuit is normal as shown in
fig. 5-5.
2.Check if the U9(IC SG3525) is normal. Cut the Utility Source , remove
the battery and remove the control board, add a 72Vdc to CN10(+) and
CN9(-) and 18Vdc to the pin 15 of U9 and short JP3 and check if the
pin 16 of U9 is 5.1V and pulses can be found at Pin 11 and Pin 14 of
U9. If not, please replace U9.
3. The MosFETs
Diode(D31-D34) maybe abnormal, please check them.
is 1.Check the related circuit shown in fig. 5-5.
2.Check if (Q10, Q12, Q15, Q17, Q19, Q21) and Diode(D31-D34) of
the driver board are defective.
3.Check if the U9 SG3525 is out of order.
4.Check if the Booster Transformer T2¡BT3 is open.
5.After replace the defective devices. To make sure the other parts of the
UPS is OK. Disconnect the logic board from driver board.
Cut off the Utility. Provide 72Vdc to CN10(+) and CN9(-) by a DC
Power Supply, connect CN4 to the main switch. Push on the main
switch and to see if DC POWER of UPS, i.e. VDD(18-16V),
VCC(12V) and +/-5V is normal.
(Q10, Q12, Q15,
27
Q17, Q19, Q21) and