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We have an APC UPS 1500 which frequently trims due to reported extended over voltage issues.
The help files tell me that to work around this I need to set the Upper Voltage to the highest setting and set the sensitivity to low.
Sensitivity is set at low already.
High transfer Voltage 253
Low transfer voltage 208
and nominal voltage 230
I see I can set the upper voltage to 267 would there be any reason not to do this?
all of ours are left to the defaults, had no issues like you describe. do you have an abnormal supply and have you measured your incoming supply's voltage?
Your nominal voltage is much more likely to be 240. The specs changed when we harmonised with Europe, not the generators and transformers. If the kit supplied by the UPS can take a 10% overload that would indicate a higher transfer of 264V as acceptable.
As mjs writes, it would be worth checking your actual voltage. If you are near a substation, it may be higher than nominal (but still in spec) or it could even be too high. In the latter case, shout at your supplier.
The main reasons i say check you supply voltage are that you could have a high voltage which could damage some non protected kit, or a faulty UPS which could damage kit. Do you have any other APC UPS's displaying a similar issue or not? One would assume that if your supply voltage is going high, other UPS's would display a similar characteristic.
Thanks Matt,
We have one of the new Energy Display meters and looking at that it seems all three phases are at a steady between 246V and 248V. Next time I notice the UPS on Trim I'll have another look.
We do have a Belkin UPS on the Admin machine and a Relios on an old server and neither of them throw up any similar problems.
I have now changed the APC's settings to an upper of 263V and the nominal to 240V and haven't had any reports from the APC since. It is close on 3 years old so is out of warranty - any ideas of a standard life for the onboard batteries - showing green currently?
At three years, I'd be starting to at least think of changing them. You don't need to buy from APC, but do make sure you get batteries designed to float for a long time, then deep-discharge.
You might find that one deep-discharge now will kill them.