I have a sicheation about converting a three phase panel

[dannay]

I have a renovation project and value engineering issues are comeing into effect. It is the intention of the electrician to re-use the existing 1-phase feeders to a new 3-phase panel (already approved. QUESTION: Are there any NEC code issues that prohibit the manipulation of the panel?

 

[caj1962]

Re: I have a sicheation about converting a three phase panel

Are you going from 3 phase to single phase? Or are you going to go single to 3. If it is the second option you don't have enough conductors. If it is the first option and the panel board interior is replaced and the unused conductor is either pulled out or isolated in a safe manner then this would not be and issue

 

[dannay]

Re: I have a sicheation about converting a three phase panel

single phase conductors to new 3 phase panel, so the electrician wants to convert the panel to single phase.

 

[bonding jumper]

Re: I have a sicheation about converting a three phase panel

there's nothin wrong with that, it might be a pain though cuz if its 30 pole, 1/3rd of the poles will not be energized.
I don't think he is allowed to put a jumper to tie in two lugs, because those lugs have ampacity ratings, and he might overload the connection, plus that would unbalance your phases and you would be carrying current in your neutral and wasting energy.
I think he wants to do this, he should leave one phase of the 3 phase panel unenergized and leave the punch outs on the panel face in for breakers that would fit in the unenergized slots, or put spare breakers in those slots with no connections to them, and mark them accordingly.

[ July 30, 2003, 10:23 AM: Message edited by: bonding jumper ]

 

[dannay]

Re: I have a sicheation about converting a three phase panel

thank you bonding jumper

 

[bennie]

Re: I have a sicheation about converting a three phase panel

How old are these panels? How do you propose dealing with existing circuits that are based on 3 phase?

This is not a good idea. This is a step back in design.

 

[dannay]

Re: I have a sicheation about converting a three phase panel

All circuits and branch feeders are existing single phase type intended to remain. The design plans intended the electricain to replace the old fuse box with a new single phase c/b panel, however the E.C. purchased three phase panels and the supplier will not accept a return on them. I could easily make the contractor buy new single phase panels but I am willing to work with him on the situation as long as the solution is NEC compliant.

 

[caj1962]

Re: I have a sicheation about converting a three phase panel

WOW. You must be working where I work. Contractor screws up and you make ok with him by accepting less than quality work. Lets think about this long term, you go back at later date to install a new circuit in the panel and can't use 1/3 of the breaker openings. This is not value engineering a 3 phase panel costs more than a single phase panel. Make the EC do his job correctly. I know neat and workmanlike is uneforceable as a code section but if this is the kind of work you get in a panel what must the rest of this guys work look like.

Sorry have been dumped on twice this week by outside contractors and just venting.

If you have the authority make him do his job right.

 

[gregoryelectricinc]

Re: I have a sicheation about converting a three phase panel

What your contractor is proposing is , as stated by others , a BAD idea. I can't think of any specific code that prohibits this but I would still make him do the job w/ 1-phase panels. A 200 amp 1-phase load center ids fairly inexpensive. I think I buy them for under $100.

 

[bbeste]

Re: I have a sicheation about converting a three phase panel

Just a question. Would this go against the UL listing of the panel?

Barry

 

[websparky]

Re: I have a sicheation about converting a three phase panel

NEC 2002 408.13 General.
All panelboards shall have a rating not less than the minimum feeder capacity required for the load computed in accordance with Article 220. Panelboards shall be durably marked by the manufacturer with the voltage and the current rating and the number of phases for which they are designed and with the manufacturer?s name or trademark in such a manner so as to be visible after installation, without disturbing the interior parts or wiring.

110.3 Examination, Identification, Installation, and Use of Equipment.
(A) Examination. In judging equipment, considerations such as the following shall be evaluated:
(7) Classification by type, size, voltage, current capacity, and specific use
(8) Other factors that contribute to the practical safeguarding of persons using or likely to come in contact with the equipment.