Cuttler-Hammer rant

[ceb58]

I had installed a UPS in one of our older communication site last week. The cabinet, maint. by pass switch, output disconnect and power modules were removed from another building and we "acquired" it. Every thing taken out neatly no problem. I had every thing wired and ready to go. My new battery packs came in and I went to start it up. Got every thing going, moved the switch to UPS and boom main breaker trips UPS shuts down on "Phase Short". What the hell. Take every thing apart to start checking all wiring, this is only about the 50th UPS like this I have installed so I'm not a virgin.
Start ohming out the wires. When I checked the UPS output to the switch it showed the phases were crossed. Doesn't matter that its a single phase unit they do not like the phases crossed. So I check from UPS to bottom side of the output disconnect, a Cuttler-Hammer 125 amp 25 kACI breaker, every thing fine. Check from top of breaker to switch, good. Check from bottom of breaker to switch phases crossed. Start looking at the breaker and find on the underside of breaker, toward the back was a sticker showing the phases are X'ed. This breaker mounts in the enclosure horizontally with the lugs on top and bottom, switch to the left is closed, to the right is open. The top left lug is common to the bottom right lug and the top right lug is common to the bottom left. What kind of crap is that. The breaker crossed phases for me. I guess under normal circumstances it wouldn't matter but these UPS just don't like it.
That's why I buy fusible disconnects for our new installs. Hate working with used crap.

 

[qcroanoke]

I had installed a UPS in one of our older communication site last week. The cabinet, maint. by pass switch, output disconnect and power modules were removed from another building and we "acquired" it. Every thing taken out neatly no problem. I had every thing wired and ready to go. My new battery packs came in and I went to start it up. Got every thing going, moved the switch to UPS and boom main breaker trips UPS shuts down on "Phase Short". What the hell. Take every thing apart to start checking all wiring, this is only about the 50th UPS like this I have installed so I'm not a virgin.
Start ohming out the wires. When I checked the UPS output to the switch it showed the phases were crossed. Doesn't matter that its a single phase unit they do not like the phases crossed. So I check from UPS to bottom side of the output disconnect, a Cuttler-Hammer 125 amp 25 kACI breaker, every thing fine. Check from top of breaker to switch, good. Check from bottom of breaker to switch phases crossed. Start looking at the breaker and find on the underside of breaker, toward the back was a sticker showing the phases are X'ed. This breaker mounts in the enclosure horizontally with the lugs on top and bottom, switch to the left is closed, to the right is open. The top left lug is common to the bottom right lug and the top right lug is common to the bottom left. What kind of crap is that. The breaker crossed phases for me. I guess under normal circumstances it wouldn't matter but these UPS just don't like it.
That's why I buy fusible disconnects for our new installs. Hate working with used crap.

Ceb, I know at one time when I was QC'ing buildings Cutler Hammer/Eaton main breakers did exactly what you are saying. A phase on main fed B phase of panel and B phase on main fed A phase of panel. I could not fathom why they would do that but hey, I'm just the QC guy. Being a single phase panel I was like you. None of the loads would care they weren't three phase.
I have only seen one other UPS that didn't like B-A input. not the same result though. It just wouldn't go on line till I hooked it A-B.
I actually am surprised I have not heard of this from our Mfgr. facility.

 

[ceb58]

Ceb, I know at one time when I was QC'ing buildings Cutler Hammer/Eaton main breakers did exactly what you are saying. A phase on main fed B phase of panel and B phase on main fed A phase of panel. I could not fathom why they would do that but hey, I'm just the QC guy. Being a single phase panel I was like you. None of the loads would care they weren't three phase.
I have only seen one other UPS that didn't like B-A input. not the same result though. It just wouldn't go on line till I hooked it A-B.
I actually am surprised I have not heard of this from our Mfgr. facility.

To be honest with you this UPS and equipment came out of one of your buildings. The building was bought through our contract and we were in there. But because we paid for the gen., ATS, UPS and equipment we removed it to use else where when the county, who owned the building, wanted to move the building some where else. So we just replaced the building with a smaller one from you guys.

 

[qcroanoke]

To be honest with you this UPS and equipment came out of one of your buildings. The building was bought through our contract and we were in there. But because we paid for the gen., ATS, UPS and equipment we removed it to use else where when the county, who owned the building, wanted to move the building some where else. So we just replaced the building with a smaller one from you guys.

Strange, It seems I have heard of UPS's being wired wrong but not sure if that is what was going on with them....

 

[templdl]

If I understood you correctly were you trying to do an in phase transfer? If so were both supplies in phase with on another? If not an out of phase voltage will cause a spike in voltage resulting in a spike in current which often results in tripping the breaker instantaneously.
Also, what C-H breaker tripped? Was it the old school thermal magnetic breaker or an electronic trip, peak sensing or RMS sensing?
If there is an adjustable trip unit how was it set?