3 wire delta corner grounded

[domnic]

I have a 3 phase 200 amp load center i want to install to replace old load center the old one is a 120/240 with 2 pole main .the new box has a 3 pole main breaker can i land the three wires on the main breaker and install jumper from b phase to ground bus? if not how do i go from a 2 pole breaker to a 3 pole this is a 240 volt corner grounded delta.

 

[roger]

I have a 3 phase 200 amp load center i want to install to replace old load center the old one is a 120/240 with 2 pole main .the new box has a 3 pole main breaker can i land the three wires on the main breaker and install jumper from b phase to ground bus? if not how do i go from a 2 pole breaker to a 3 pole this is a 240 volt corner grounded delta.

Were there no 120 volt loads served from the old panel?

Roger

 

[domnic]

Were there no 120 volt loads served from the old panel?

Roger

it is a corner grounded 240 volt 3 phase 3 wire .no 120 volts.

 

[glene77is]

Please describe the OLD system.
Skip two blank lines.
Then describe the NEW system.

 

[templdl]

The way that I understand the NEC. Feel free to use a 3 phase panel w/3p breakers for a corner grounded delta. As long as the "grounded" conductor is switched with the ungrounded conductors it is treated the same as any 3ph ungrounded conductors except that on of the lines happens to have been grounded.
You would bring the EGC out as you woulld normally do.

 

[domnic]

Please describe the OLD system.
Skip two blank lines.
Then describe the NEW system.

Old system is a 3-phase corner grounded delta wired to a single-phase 120/240 volt panel. This was very common in our area, St. Louis. There are still a lot of these systems out there. These systems are not up to code now.


I want to install a 3-phase panel with each current carrying conductor going to a main breaker, which would be a 3-phase breaker. Since there is only 3 wires coming to the service, I would have to jumper the B-phase, which is a grounded conductor to my grounding bar for equipment grounds. Has anyone out there installed a 3-wire 3-phase corner grounded delta breaker panel?

 

[haskindm]

If I understand what you are trying to do, one of your bus bars will be grounded, as will your neutral/ground bar. I cannot see any way that this will be "installed according to the listing and labeling" of the panel. If anyone mistakenly installed a 3-pole breaker in the panel they would be putting phase current on any grounding conductors installed to the panel. Why not get a single-phase panel and install it properly? This just seems like a bad idea unless I am totally missing something.

 

[jim dungar]

I want to install a 3-phase panel with each current carrying conductor going to a main breaker, which would be a 3-phase breaker. Since there is only 3 wires coming to the service, I would have to jumper the B-phase, which is a grounded conductor to my grounding bar for equipment grounds. Has anyone out there installed a 3-wire 3-phase corner grounded delta breaker panel?

I have seen systems installed like this.

However since UL has gotten into the act of listing corner-grounded equipment (in the old days manufacturer's often "self-certified" their equipment) I cannot remember seeing 3-pole breakers used as service entrance equipment.