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

4.4.

UPS Fails to Backup When Blackout

Check Items
Battery is weak and no
battery charging urrent
When it is in charging
mode.
Battery is defective
Battery harness is
loose in connection.
DC to DC converter is
abnormal and/or the
battery fuse is
defective.
The IC of DC Booster
stage is out of order.
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 43.2Vdc,86.4Vdc,
115.2Vdc for MS1K(R), MS2K(R) and MS3K(R) respectively. 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 shown in fig. 4-5.
2. Check if Q15-Q20 , D30-D33 of the driver board are defective.
3. Check if the U9 SG3525 is out of order.
4. Check if the Booster Transformer T2 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
36Vdc to CN5(+) and CN4(-) by a DC Power Supply, connect CN2 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.
1. Check the related circuit is normal as shown in fig. 4-5.
2. Check if the U9(IC SG3525) is normal. Cut the Utility Source , remoe the
battery and remove the control board, add a 36Vdc to CN5 and CN4 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 the U9.
3. The MosFet (Q15-Q20) and Diode(D30-D33) maybe abnormal, please check
them.
FIG. 4.4
19