SURT5000XLI Internal Fault

[Anonymous user]

My SURT5000XLI S/N NS0604008234 was switched off for the Christmas break. When I switched it back on, after a few minutes, the internal fault light came on and the charge LEDs 3 & 4 (Counting from the bottom) came on. Searching the forum I found a similar problem in this post "SURT3000XLI FAULT" which said the error code reffered to a capacitor soft start up fault. Assuming the the code for my UPS is the same as this post do I simply need te replace the two huge capacitors on the main board to fix the problem?
Thanks.

[Anonymous user]

Thanks for getting back so quickly.
The unit is not supplying power at all now but it did for a few minutes after first switching it on. Until then it showed a near full charge on the batteries. All the batteries in the expansion unit measure 105.5V with105V and 104.8V in the UPS itself.

[BillP]

so does the UPS start in bypass at least or is not outputting power at all? is it possible to use a voltmeter to check the battery voltage? i am wondering if the batteries discharged a lot while the UPS was turned off. for the future, when you turn off the UPS, you should disconnect any batteries, especially on these models, to have them avoid discharging into the unit while turned off.

let's measure that batt voltage if at all possible and if that is below a certain amount then that may be the issue here. you can measure each string and see what you get.

this is technically a Battery Capacitor Soft Start Fault.

[BillP]

hmm ok those should be good. when you arent working on this, i'd recommend leaving them disconnected to avoid any damage to them while the UPS is not operating correctly.

what i would try is a braindead on the UPS to see if we get anywhere. we need to cut any power to the UPS and remove it from AC power. if possible, you can just trip the input circuit breaker on the back of the unit near the input plug/hardwire connection if it has one, which i think it does. then, make sure all external battery units are unattached and the UPS batteries are and then hold down the off (o) button for 5-10 seconds and see if you hear a click and see some LEDs flash. then reconnect the batteries and put the breaker back to the normal position and see if the UPS starts when you press the on/test button for a second.

[Anonymous user]

With the input power removed, pressing the off button causes a click sound and the fan to stop rotating. I connected the external batteries and reapplied input power and the fault light immediately comes on. Pressing the off button causes the fault light to go off and there is a click noise but after 5 seconds the fault light comes back on by itself. Pressing the on button does not produce any obvious results.

[BillP]

ok, well with that, i'd have to say there is an internal issue with the UPS. we have done what we could and like i said, i'd leave your batteries fully disconnected - from the UPS and also the external battery pack so you can use them elsewhere or with a replacement unit.

we dont repair these at all so i'd have to recommend replacing the UPS or trying to figure it out at your own risk. we also don't provide schematics for this type of UPS (or any for that matter). if it is under warranty, you can get a warranty replacement by contacting tech support in your region.

[Anonymous user · Accepted solution]

Thanks for your help any way.