quick electrical question (3 phase)

[ericheartsu]

We are taking over a warehouse that is behind ours. No one is in it, and the original builder of the property built it as his finishing warehouse (he had a furniture business).

I can't figure out if it's a three phase panel or not! It's a sub panel for sure, that runs off a 3 phase (4 wire) 100amp 3 pole breaker from our main 3 phase panel.

The wires run underground to this back warehouse, into the panel, but then they run into a 100amp 3 pole breaker, not into the main power center for the panel! I've included a picture. The 4 wires come in from the bottom of the picture, and run right into that 100amp breaker.

so, can anyone tell me if i have three phase service on this panel?

[Inkworks]

Looks like it to me, a photo of the top where the main feed comes in would cinch it.

[ericheartsu]

Looks like it to me, a photo of the top where the main feed comes in would cinch it.

thats the thing though! there is no main feed at the top! All the power comes up from bottom! the 4 wires that come in, are run from a breaker on our main panel

[244]

We are taking over a warehouse that is behind ours. No one is in it, and the original builder of the property built it as his finishing warehouse (he had a furniture business).

I can't figure out if it's a three phase panel or not! It's a sub panel for sure, that runs off a 3 phase (4 wire) 100amp 3 pole breaker from our main 3 phase panel.

The wires run underground to this back warehouse, into the panel, but then they run into a 100amp 3 pole breaker, not into the main power center for the panel! I've included a picture. The 4 wires come in from the bottom of the picture, and run right into that 100amp breaker.

so, can anyone tell me if i have three phase service on this panel?

Its a mess but its three phase. Looks like the main breaker might be bad so they are backfeeding the three phase through the 100 amp breaker. They are also picking up power from the three phases to run single phase as well. All dangerous and definitely against any states code!!!

[ZooCity]

What 244 said.  Grab a new panel for this space and hook it up right. 

Depending on your 3ph service, yes you get 3ph coming in but, in the case of ours which is a high leg delta the high or "stinger" leg can be skipped to put 1ph 120 and 240v breakers on.  The 3ph breakers can go anywhere but you need to skip the high leg with the 1ph breakers.  Not sure if this applies to your service or not but maybe helpful.

[ericheartsu]

our electrician friend also just told me about the backfeeding. Almost nothing that was pre-installed in this shop is up to code, but we are trying to fix that!

thanks guys!

[jvanick]

that looks to be a Siemens bolt down panel, just installed 'upside down' so that the main breaker is at the bottom instead of the top.

nice panels actually, I have installed tons of them in datacenters.

get a new 3ph main breaker...

also, if it's a sub panel, it doesn't look like it's grounded correctly.  That panel appears from your pic to have neutral and ground bonded.  Sub panels are supposed to have separate ground and neutral feeds as of NEC 1999 (might be wrong on this, can't remember for sure)

* I am no longer an electrician, so... make sure you get good advice from your electrician, pull the appropriate permits, and get it inspected afterwards. 

[Inkworks]

also, if it's a sub panel, it doesn't look like it's grounded correctly.  That panel appears from your pic to have neutral and ground bonded.  Sub panels are supposed to have separate ground and neutral feeds as of NEC 1999 (might be wrong on this, can't remember for sure)

up here sub panels do not get the nuetral bonded to ground, only the main panel.

* I am no longer an electrician, so... make sure you get good advice from your electrician, pull the appropriate permits, and get it inspected afterwards.

^^^^^ this. I do my own work, but I get it certified by a real electrician.

[Binkspot]

Junk it, a new main for that panel is proberly more expensive then a whole new panel with the main. Plus unless you have the know how every time you want to add a breaker you have to kill the service. Bolt ins have there place but a print shop is not one. They are a bit more expensive also.

[Gilligan]

I do have a couple of those main breakers that are still good if you need one.

[tancehughes]

Somewhat off subject here, but I hope your new place isn't huge. The amount of money we have spent on electrical work in the past six months has been insane. We have 3 phase here too and just had to get a new panel box for some equipment were adding. The bills are outrageous.

Gotta pay to play I guess


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[tonypep]

It isn't. I'd say it's right sized.