Excessive Charging Voltage for SURTD5000XLI

[BillP]

Can someone please advise if this is repairable, whenever I conduct PM to the UPS, I always check its charging voltage, and the range that I always get is from 215-219VDC. Now, when I tried to check the said UPS Model I had a reading of 235V DC which I think is too high for the charging of the UPS. How can I repair or rectify this concern with the UPS? Any help is much appreciated. Thank you. 

[BillP · Accepted solution]

hello,

Try out the following only at your own risk, I take no responsibility if something goes wrong. I tested this method only on SUA**** series of APC UPSes so I don't know if it works at all for SURTD.

Remove all accessories connected to the UPS (eg. Smart slot cards)

Connect with a terminal program to your UPS using the RS-232 port (not USB!)

The correct settings for the COM-connection are 2400 Baud, 8 data bits, 1 Stop bit, no parity, protocol Xon/Xoff. Make sure that the option FIFO activated is unchecked (if there is such option in your terminal program, that is). 

When the connection is established to the UPS, press Shift + Y (capital Y) the UPS should respond with 'SM'

Type 1, wait 1.5-3 secs and type 1 again (Should return 'Prog') 

Press Shift + B (capital B), UPS should respond with a hexadecimal value (write it down so if something goes bad you can reset it to this value)

Press + or - sign to increment/decrement the value, and the charger voltage should change. It *might* happen that the voltage detected by the UPS remains the same, but the voltage measured at the battery terminals do change (false battery voltage reading). You can't do anything about this, it is either high charging voltage and accurate battery voltage reports, or adjusted charger voltage and inaccurate readings.

Press Shift + R (capital R) to close the session, UPS should respond 'BYE'

Close the terminal.

Please note that these steps modify things inside the EEPROM, so it is a very delicate matter. Do this only if you really must, otherwise take the unit to trained service personnel for repairs.