Unusual Question - Powering a single phase panel with 120 Volts

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jap said:
There's a special brand name for the panels used in this type of installs.

They're called Whodoneits.


Jap>
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Well, sometimes it's hack, but I do not believe there's anything not code compliant about using a 120 / 240 panel with one ungrounded feed. the only reason I suggested a 6 breaker panel instead of A4 is it someone might want to add a small lighting load in the future or a small transformer for something else needs to be on a third circuit. The panel and Breakers probably cost about 40 bucks
 
jap said:
Go read post #9 again carefully.

Then you can take the question mark and the smiley face of the end of your sentence above.

JAP>
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Jap as the acting AHJ are you saying you would turn down the proposed 30A 120V two circuit loadcenter because it had two #10's under one lug that is rated for 8-1/0 @ 75C. Which section/paragraph of the NEC would you cite?
 
I would run it straight thru the lug, skin a bit off the insulation for the connection to the lug, and unspliced run it to the other lug. And save myself the cost of a wirenut. So the lug only has the one wire in it. It's how I undercut the competition. I under bid them consistently by ten cents I save using my secret method.
 
I've read through this thread a couple of times. I still can't see what's wrong my simple solution - and one we have successfully implemented many times.
 
Besoeker said:
I've read through this thread a couple of times. I still can't see what's wrong my simple solution - and one we have successfully implemented many times.
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Original poster doesn't need a transformer, he needs 20 amp circuits because of manufacturer specs. He has a 30 amp source.

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And I have no idea why were talking about placing a jumper across the lugs... There are two breakers... two.
 
macmikeman said:
I would run it straight thru the lug, skin a bit off the insulation for the connection to the lug, and unspliced run it to the other lug. And save myself the cost of a wirenut. So the lug only has the one wire in it. It's how I undercut the competition. I under bid them consistently by ten cents I save using my secret method.
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I like to strip off enough insulation so I can double the wire back then jump to the next lug but I read enough about that being a hack method so I’ve reverted to the wirenut. Usually.
 
Besoeker said:
Wouldn't that depend on where the 120V comes from?
There's bound to be a transformer at some point to get 0-120V
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I take it the original posters Black Box setup is perhaps a 3600 VA transformer. Maybe not. I don't care if he has a pet chupracabra spinning an old Flixible bus alternator to get 120 volts and 30a. He has wrote that he is stuck with that set up, whatever it may be.

You're right there's a transformer somewhere. He already has 120 volt, no need for another transformer.
 
After reading a few of these installation practices I threw up in my mouth a little bit. :happyno:


JAP>
 
JFletcher said:
Original poster doesn't need a transformer, he needs 20 amp circuits because of manufacturer specs. He has a 30 amp source.

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And I have no idea why were talking about placing a jumper across the lugs... There are two breakers... two.
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Because they intend on energizing both buss bars in the panel they are feeding.


JAP>
 
jap said:
Because they intend on energizing both buss bars in the panel they are feeding.
JAP>
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Can't they both be fed from the same single 120Vac supply?
I think Petersonra suggested something like that in post #2.
 
JFletcher said:
I take it the original posters Black Box setup is perhaps a 3600 VA transformer. Maybe not. I don't care if he has a pet chupracabra spinning an old Flixible bus alternator to get 120 volts and 30a. He has wrote that he is stuck with that set up, whatever it may be.

You're right there's a transformer somewhere. He already has 120 volt, no need for another transformer.
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Oh, you are familiar with the job. And the chupacabra's name is Phillipe and he loves peanuts.
 
I have spoken to several people outside of this thread, one being Mike Holt himself, and they all said (one after disagreeing and bringing it to his state board) that this is a code compliant set up. This is a project that will have multiple sites through the country. It is an issue at two sites as the "black box" is already built. The design of the "black box" is being changed to provide a single phase 208V output of the "black box" so this will not be an issue in the future. I am an engineering who was an electrical contractor for about 10 years and it is an unusual situation that I personally have never done or seen in the field. I could not think of any violations with the set up as I proposed, but I did not know for sure, that is why I posted the question. I was looking for an NEC violation. I am sure at construction and inspection times this will create many RFI's and I suspect that I will have to discuss with the inspector as well. (Especially considering my friend that disagreed until he brought it to his state board is an inspector)

I appreciate everyone's input on this, I know it is unusual and not something that I would typically do, it is just what I am stuck with for these two locations.
 
This is pretty common in my line of work .... lots of IG systems for POS equipment. They want it all from a single phase.

One particular customer uses an in-wall UPS, fed from a single 20A breaker, and then on to a 24-space panelboard with 120v only. They’ll have 6-8 circuits out of the panelboard for POS equipment.

Some engineers will just call for a 100A 120/208v feeder to the panelboard, and then have you put all the loads on the same buss.


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brantmacga said:
This is pretty common in my line of work .... lots of IG systems for POS equipment. They want it all from a single phase.

One particular customer uses an in-wall UPS, fed from a single 20A breaker, and then on to a 24-space panelboard with 120v only. They’ll have 6-8 circuits out of the panelboard for POS equipment.
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What's IG and POS equipment?
Ignorant Brit here.
 
Besoeker said:
What's IG and POS equipment?
Ignorant Brit here.
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IG is Independent Ground, which uses an insulated EGC which runs all the way back to the main bonding jumper location without interconnecting with other wire or raceway EGCs. In theory this will reduce coupling of voltage offsets into patient-facing metal surfaces when leakage or fault currents flow through the other EGCs.

POS equipment is, in other contexts, Piece of S... equipment, but here is more likely Point Of Sale equipment such as cash registers and ordering systems.

Arrogant Yank here!​
 
GoldDigger said:
IG is Independent Ground, which uses an insulated EGC which runs all the way back to the main bonding jumper location without interconnecting with other wire or raceway EGCs. In theory this will reduce coupling of voltage offsets into patient-facing metal surfaces when leakage or fault currents flow through the other EGCs.

POS equipment is, in other contexts, Piece of S... equipment, but here is more likely Point Of Sale equipment such as cash registers and ordering systems.

Arrogant Yank here!​
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Thank you for that.
 
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