Smart-UPS RT 10000 XL Problem

[BillP]

Hi, we are having some troubles with our Smart-UPS RT 10000 XL.
We have got 3 installed and they are configured to do a self-test all 14 days, which is default.

We have our smart-UPS since 4 weeks now and noticed, that every 14 days (so the day of the self-test) our Residual Current protective Device (FI) gets activated. And the UPS runns on battery.
Unfortunately we then have problems activating our RCP (FI) again. After turning off some power lines at the back of the UPS it then luckily works.

Well ok, first of all we will now deactivate the sef-test but this is not a solution!

During a self-test the UPS switches to battery and when it sould switch back there seems to be a problem. Our opinion is, that during the switch back to normal operation there is a too high power need at this moment which then acitvates our RCP (FI).

So I am looking for a possibility to delay the boot or switch from battery on each UPS.
Maybe also one of our UPS has an issue?

Does this make sense?
Thanks for your help!
Regards.

Message was edited by: ollivetti

[BillP · Accepted solution]

hello, i found some documentation we have on this topic:

The couple of reasons that we wouldn't recommend an RCD on the input side of the UPS are as below

1) The cumulative leakage current that would appear at the input of the UPS is the sum of leakage currents from the UPS plus all attached load devices, this might easily exceed the 30mA trip setting on the RCD, as some of the IT gear is high leakage devices.

2) Effectiveness of an RCD on the input side of the UPS under modes of UPS operation cannot be guaranteed especially when the UPS goes to battery and the unit activates back feed protection.

3) The UPS employs common mode noise and surge suppression as part of its essential function which might lead to nuisance tripping of RCD connected on the input side of the UPS

Considering the above factors an RCD on the input side of the UPS might defeat the essential purpose of availability.

Australian Standards do recognize this high availability requirement (for UPS and IT equipment) and is working on an amendment to AS/NZS3000 - 2007.