UPS Output Voltage going High
UPS Output Voltage going High
(OP)
This may not be the right forum but....
We have had two incidents lately of the output of UPS's going to overvoltage and burning out downstream power supplies. Does anyone have experience of this type of fault.
Units are Emerson Liebert 230V output 50HZ 6kVA and 4.5kVA
We have had two incidents lately of the output of UPS's going to overvoltage and burning out downstream power supplies. Does anyone have experience of this type of fault.
Units are Emerson Liebert 230V output 50HZ 6kVA and 4.5kVA






RE: UPS Output Voltage going High
Also, I think a model number would also help.
RE: UPS Output Voltage going High
GXT2U
RE: UPS Output Voltage going High
Plus there is not enough information to comment on? What were measured over voltages?
It could be cheap power supplies too!
RE: UPS Output Voltage going High
RE: UPS Output Voltage going High
What are the reasons Liebert giving? If you dont share those here how can one tell if they may be right or wrong?
Knowing Liebert for years, I would still give them benefit of doubt unless you have some information to disprove them.
You have provided zero information so far to make any technical assessment of any kind.
RE: UPS Output Voltage going High
RE: UPS Output Voltage going High
RE: UPS Output Voltage going High
I am interested in whether others have had a similar problem and what they have found so that I can look in other directions and explore other possiblities. I do not think that as a responsible engineer I should give 'the benefit of the doubt'
RE: UPS Output Voltage going High
You mention that the output voltage was 278 volts. How was this measured? Was this measurement taken whilst your downstream equipment was damamged ar taken at a later time?
Was the UPS on-line at the time or was it in bypass (reserve) mode?
RE: UPS Output Voltage going High
RE: UPS Output Voltage going High
If there were no alarms, then something is wrong with the internal monitoring circuits and with the output regulation.
Alan
----
"It's always fun to do the impossible." - Walt Disney
RE: UPS Output Voltage going High
Was the output voltage of the UPS checked with an oscilloscope to see whether the voltage was still sinusoidal?
As described it does sound very peculiar. I can only surmise that for things to stuff up this badly with the UPS that there is some severe software error.
RE: UPS Output Voltage going High
RE: UPS Output Voltage going High
The only thing that worries me is that the AEG system detected the high voltage and switched off the inverter. This does not seem to have happened in your case.
UPS engineer http://www.powerups.co.uk