Thank you for your prompt replied.
Your info was helpful to me.
Anyway, just wonder do APC itself provide a certified electrician inspection service?
I had a issue on the site wiring fault.
First, I had two UPS in the server room, when connected to socket, both of the site wiring fault LED will light up.
The issue solved after check by electrician and installed a ground wire to server room on May 2014
One 29 July 2014, one of the UPS site wiring fault LED light up again.
From the log, I can see that the site wiring fault happen and become normal within few seconds.
It keep repeating the behavior for few hours, and stop.
After a period (within 5-6 hours), it happen again.
I really have no idea why is the issue happen again, it work fine before.
Anyone can help?
What type of UPS is this? Do you have a model number?
Assuming a Back UPS or Smart UPS, the typical reasons behind it are loose or missing ground, reversed polarity, and overloaded neutral. The stuff that sounds like it could come and go are the loose ground and overloaded neutral.
Do you know the cause of it last time and what the electrician addressed? I would think you may need to have him/her come check it again while the site wiring fault is active since you did indeed have this issue before.
The one with fault is APC Smart UPS – 2200.
The one without any issue is APC Smart UPS – 1500.
Last time, the electrician just installed ground wire and the problems was solved.
I really cannot understand why is the fault happened again.
What do you mean by loose ground?
Anyway, what is the worst case if I just let the fault happening?
Thank you for your time reviewing my issue.
Regarding a loose ground, I was referring to a physically loose or unstable connection either in the receptacle or upstream where it connects to your panel in the building.
If you let the fault keep happening, it could interfere with the ability for the UPS to deal with a surge and shunt it to the ground (but it should ultimately sacrifice itself before your equipment) and it would also avoid any possible Equipment Protection Policy (but I think that only applies to the USA actually where we have that).
I know we do not here in North America and I have never heard of us doing that in any other region so my "gut" tells me the answer is no.
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