Smart UPS units will not power on

[Anonymous user]

My firm has 4 UPS units that will not power on. 2xSU1400RM2U and 2xSU1500RM3U. I know that the batteries are likely shot in all of the units. I have read on these forums that these units will not power on if the batteries are dead. While these are shot they do carry some voltage. How much voltage is necessary to get the unit to power on? Also, if the batteries are the issue and prevent the unit from powering up would any of the LEDs on the unit light?

Thanks
Steve

[Anonymous user]

This is the best bit of info here on these boards about these UPS's in general.
I had a DEAD Smapt UPS 2200net and i could net get it to respond in any way shape or form.
had replced the resistors,R38 & R43 with 1k and Caps C34 & c35 22uf 16v
and still nothing. then I charged up the caps through the battery connections, the one in front and the one in rear,
with a alligator clip wire bridging both in series, (just like the big yellow wire does when batteries are connected)..
and BAM...Came to LIFE. Started trying to charge the batteries that weren't there.
kept running too. this is a great test to verify things are working. Heck i don't wanna spend $200 on batteries if they aint gonna work.

Boooooooooooooooooooooooo
to APC for NOT supplying any info to a whole bunch of very qualified techs on this board, and NOT supplying schematics
or any kind of tech support. Its bull crap.
you guys know you had a engineering issue with those resistors, and did nothing about it.
Im surprised there was no class action lawsuit brought against you for it.

[Anonymous user]

I was wondering about the configuration of those batteries. Depending on the wiring 12v, 24v or 48v were all possible. What is the configuration for a SU1400RM3U Smart-UPS? If I was a betting person I would say it too was 48v.

Steve

Message was edited by: ilecoder

[TheNotoriousKMP_apc]

I believe the lowest threshold for the batteries is somewhere between 16 and 18VDC. With a bad set of batteries, the ONLY LED that may illuminate on the UPS is the Site Wiring Fault (if one exists). The rest of the panel will not light.

[Anonymous user]

I have the 2xSU1400RM2U at home with me. I pulled the battery tray and attempted to force a charge into the four small SLA batteries. One battery is holding at 8v, another battery is reading 7.2v, and the last two read around 6v. I doubt that these voltage readings would hold up if any type of load is placed on them.

I am just attempting to prove if the units function and justify new batteries.

I think I am going to suggest that one battery cartridge be purchased and that if both units can be shown to work off that one unit that another cartridge could be purchased.

Steve

[Anonymous user]

The control module requires presence of voltage across the battery terminals before activating anything.

There is a set of large capacitors at the battery connection. You should be able to feed the battery terminals with a 12-15v DC adapter,which will actually charge up the capacitors to 15-20v. Give it about a minute to "charge up" the capacitor, then disconnect the wallwart. Measure the voltage across the battery terminals. You should see the voltage retained by the capacitor. After you check the presence of 15-20v, you should be able to plug in the UPS and turn it on.

It will turn on then immediately shut off as it attempts do a self-check and transfer to battery power.

If you can duplicate this, I would go ahead and try a new battery. I don't think you'll have any trouble finding a 12-15v wall-wart around the office. Just make sure the output is DC and observe the polarity.

Also, are you going to be putting all four units into service within the next month or so? If not, only order replacement batteries for units that you will be using right away. If you replace the battery and put the units back in storage for later use, you'll just ruin them again.

Edit:

RBC24 is 12v 8 or 9Ah x 2 in series and two strings of them in parallel forming a 24v 16/18 Ah battery pack.

Message was edited by: KVAr

[tzobor_apc]

KVAr, I tried the trick with my SUA1500I and it worked! At least now I know only the batteries need replacing, not the whole unit. Thanks for a good advice, mate!

[Anonymous user]

KVAr

I opened up one of the SU1400RM units - it's actually a DL1400 which means that it was purchased from Dell. The wiring harness tells me that the four batteries are configured as 24v at 16ah. The original batteries are four 12v, 8ah batteries.

I have to believe that the SU1400RM2U units have a similar battery arrangement since they do use the same battery - just in a tray configuration. I do not understand why the batteries were glued into the tray.

Steve

[Anonymous user]

All microprocessor controlled Smart UPSs are like that. Unlike the older Back-UPSs, battery voltage is required. So, I think buying one battery pack or the aforementioned wall wart trick should do.

[TheNotoriousKMP_apc · Accepted solution]

I finally decided to take a voltmeter to the same exact unit that we have in our lab.

It read 27.66 VDC.

So they're definitely a 24VDC system.