# Welders causing UPS to act up?



## brian john (Mar 11, 2007)

"By George" said:


> For about a month the UPS battery back up at the computer stations have been switching back & forth from line power to battery power. (5 stations and 1 server) The data log is stating that the problem is caused by "noise" in the line. (Not under or over voltage)
> We think now the noise is being caused by the TIG welders in the warehouse, which are fed from a 3 phase 480 volt transformer feeding from the office 120/208 service.
> I am reading into some HF radiation info from the welding supplier which calls for bonding the death out of the framing, plumbing, water lines (basically anything that is metal has to have a ground bond attached)
> Has anyone ever ran across this type of issue & what corrections were made to fix?
> Thanks for the help


Bond your butt off all you want, all you will be doing is wasting copper. If it is a EMF issue distance or a Faraday cage. 

If I understand you correctly, you have a 208/120 VAC 3 phase service that feeds the office and a 480 transformer for the welders?

Is the transformer a 208 DELTA to 480/277 wye? If the transformer is 208/120 wye to 480 delta this MIGHT be contributing to the issue. Get a 208 delta to 480/277 wye.

You could try a shielded isolation transformer for the office circuit one to one ratio. I would buy a small plug and play unit and see if it works.

I assume you are depleting the UPS batteries?


----------



## RIVETER (Sep 26, 2009)

"By George" said:


> For about a month the UPS battery back up at the computer stations have been switching back & forth from line power to battery power. (5 stations and 1 server) The data log is stating that the problem is caused by "noise" in the line. (Not under or over voltage)
> We think now the noise is being caused by the TIG welders in the warehouse, which are fed from a 3 phase 480 volt transformer feeding from the office 120/208 service.
> I am reading into some HF radiation info from the welding supplier which calls for bonding the death out of the framing, plumbing, water lines (basically anything that is metal has to have a ground bond attached)
> Has anyone ever ran across this type of issue & what corrections were made to fix?
> Thanks for the help


It would take just a simple waveform test for that buss.


----------



## Jlarson (Jun 28, 2009)

"By George" said:


> For about a month the UPS battery back up at the computer stations have been switching back & forth from line power to battery power.


Like little plug in units right?



brian john said:


> Bond your butt off all you want, all you will be doing is wasting copper. If it is a EMF issue distance or a Faraday cage.


I'd just try some EMI filters before I go building a big Faraday cage around the welding area.


----------



## RIVETER (Sep 26, 2009)

"By George" said:


> For about a month the UPS battery back up at the computer stations have been switching back & forth from line power to battery power. (5 stations and 1 server) The data log is stating that the problem is caused by "noise" in the line. (Not under or over voltage)
> We think now the noise is being caused by the TIG welders in the warehouse, which are fed from a 3 phase 480 volt transformer feeding from the office 120/208 service.
> I am reading into some HF radiation info from the welding supplier which calls for bonding the death out of the framing, plumbing, water lines (basically anything that is metal has to have a ground bond attached)
> Has anyone ever ran across this type of issue & what corrections were made to fix?
> Thanks for the help


What kind of noise?


----------

