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ups fault

ups fault

ups fault

(OP)
im having problems with 625kva ups which keeps dropping its internal by-pass.
the supply has been tested and shown to healthy,the inverter and thyrister stacks on the ups have been replaced.
the fault is very intermittent,as shows itself wether the ups is on load or not.
some ideas or thoughts would be most welcome.
 

RE: ups fault

Not enough info.  Get someone experienced on site. It could be in the UPS or may be a reaction to something happening outside UPS, even downstream, such as STS switching, if there.  

Rafiq Bulsara
http://www.srengineersct.com

RE: ups fault

(OP)
thanks but what more info would you like?

the ups runs fine but as soon as you close input2 from the input splitter the ups keeps dropping the thyrister switch.

we have run the ups on a seperate transformer and on its generator which have been fine.

 

RE: ups fault

A lot! From experience, I can tell you one thing: This not something you solve on internet. It takes time and effort to review of your system configuration, assistance from the manufacturer's field service, interview on-site personnel and more.

You probably will get some conjectures from some here, but they are just that.

Rafiq Bulsara
http://www.srengineersct.com

RE: ups fault

(OP)
i have had several so called experts visit site, from the transformer manufactures to switchgear experts and ups engineers from germany.
  

RE: ups fault

The key is to get an engineering consultant who has the experience with designing and troubleshooting such systems. Individual mfr. reps/ techs necessary, but not sufficient, part of the team as they only vouch for "their" equipment not for "your" system. You need a good consultant on "your" side, who can shift through facts and BS from vendors.

Rafiq Bulsara
http://www.srengineersct.com

RE: ups fault

Germany... so it's likely either a Siemens unit or AEG? Who is the system integrator?
  

----------------------------------
  
If we learn from our mistakes I'm getting a great education!
 

RE: ups fault

Well here is a conjecture:  Do a thorough visual inspection when the unit is shutdown, de-energized and made safe. Loose connections, accumulations of dirt, rodents, bugs, Loose crimps? (someone else on the forum had that recently...) water ingress, humidity, tracking on PC boards, cold solder joints, corrosion... Have your reps do the same on their equipment. Get out around, under and over the equipment. Do not sit in an office and listen to reports or what others say they did. ***Do Not Assume***(I learned that from an old long gone field engineer decades ago)...

This may be a bit harsh but so it is in the fiekd.

What kind of plant is it actually...Good or agressive environment..?? salty, sandy, wet, chemical, sewage...or a perfect air conditioned computer center...

rasevskii

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