# Best way to do this one..



## Magnettica (Jan 23, 2007)

Three-phase 120/ 208V residential service. The only 3-phase loads are (2) AC CU's. I'm thinking of (2) 30-circuit 150amp MB panels. The set up they have here now is everything is single phase except for the AC equipment on the left. I'm concerned about balancing the load because i don't balance 3-phase loads every day like some people.


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## jwjrw (Jan 14, 2010)

You won't have any issue balancing 2 three phase a/c units.


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## BuzzKill (Oct 27, 2008)

What a clusterf*ck that is! I have the same problem coming up shortly, balancing a 3phase system with mostly single phase loads. PIA.


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## McClary’s Electrical (Feb 21, 2009)

Magnettica said:


> Three-phase 120/ 208V residential service. The only 3-phase loads are (2) AC CU's. I'm thinking of (2) 30-circuit 150amp MB panels. The set up they have here now is everything is single phase except for the AC equipment on the left. I'm concerned about balancing the load because i don't balance 3-phase loads every day like some people.


 
Are you on '08 yet? I would set a 60 circuit 3 phase load center


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## Magnettica (Jan 23, 2007)

mcclary's electrical said:


> Are you on '08 yet? I would set a 60 circuit 3 phase load center


Who makes the 60 circuit... CHCH?


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## slickvic277 (Feb 5, 2009)

Magnettica said:


> Who makes the 60 circuit... CHCH?


I think square d does. I posted a link a long time ago....


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## Magnettica (Jan 23, 2007)

Yes, 2008 NEC here.. rehabilitation sub-code here though..


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## slickvic277 (Feb 5, 2009)

Looks like a nightmare. So what's your plan? Piece of trough across the top and nipple down into two panels?? What about the S.E.C are they gonna have to be bugged?, I cant tell from the picture. Or are you bringing in new conductors too?


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## Magnettica (Jan 23, 2007)

slickvic277 said:


> Looks like a nightmare. So what's your plan? Piece of trough across the top and nipple down into two panels?? What about the S.E.C are they gonna have to be bugged?, I cant tell from the picture. Or are you bringing in new conductors too?


The exterior's in pretty good shape. I'll give them the option here of doing the whole thing vs upgrading the panel(s) and grounding.


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## slickvic277 (Feb 5, 2009)

Magnettica said:


> The exterior's in pretty good shape. I'll give them the option here of doing the whole thing vs upgrading the panel(s) and grounding.



Cool. I wouldn't sweat balancing the loads to much. You only have two 3 phase loads right? Other then that, pay attention in that mess for circuits with shared neutrals and you should be fine.


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## nitro71 (Sep 17, 2009)

You don't need to worry about balancing the loads. They'll be close enough for the POCO. This actually looks like fun and shouldn't be that complicated. Label well!


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## B4T (Feb 10, 2009)

Go with a 200 amp. single phase and a 100 amp. three phase panel..


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## 480sparky (Sep 20, 2007)

B4T said:


> Go with a 200 amp. single phase and a 100 amp. three phase panel..



That won't balance the loads out very well.


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## RePhase277 (Feb 5, 2008)

Put one panel on A-C, and the other on B-C, and divide the circuits between them.


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## Shockdoc (Mar 4, 2010)

Well it depends, is it a open delta service, closed delta , one 3 ph 42 ckt panel, open delta, like B4 wrote, two panels.


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## NolaTigaBait (Oct 19, 2008)

Is it a wye?...Just get one big 3 phase panel...I think ,like mcclary said...


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## Magnettica (Jan 23, 2007)

NolaTigaBait said:


> Is it a wye?...Just get one big 3 phase panel...I think ,like mcclary said...


Yes, 120/208. :thumbup:

Looks like Cutler-Hammer doesn't make a 60-circuit triple phase panel :no: so I'm gonna have to check out Square D for it.


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## MDShunk (Jan 7, 2007)

What's the demand load here? 200 amp or less?

If so, I'd probably do a gutter tap to (2) 100 amp single phase MB panels and (2) three phase service equipment rated discos for the a/c stuff.

Forget about balancing anything resi, even three phase. It will NEVER happen.


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## NolaTigaBait (Oct 19, 2008)

Ron, how many total spaces do you need?


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## 10492 (Jan 4, 2010)

Magnettica said:


> I'm concerned about balancing the load .


Why?

The customer doesn't own the transformer.

I'd put the two 150 MB panels in and be done with it.


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## Magnettica (Jan 23, 2007)

NolaTigaBait said:


> Ron, how many total spaces do you need?


43 including the (2) 3-phase loads. 


This is a 208 volt service. Therefore it's a Wye connected system.


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## NolaTigaBait (Oct 19, 2008)

Magnettica said:


> 43 including the (2) 3-phase loads.
> 
> 
> This is a 208 volt service. Therefore it's a Wye connected system.


I know...JUst making sure we are on the same page...If you can't get that 60 space, it may be cheaper to just get a single phase panel(im assuming there are no mwbc's using 3 circuits) and then 2 disco's for the a/c's...

That large panel would really save time...I wonder what they cost?


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## Magnettica (Jan 23, 2007)

MDShunk said:


> What's the demand load here? 200 amp or less?
> 
> If so, I'd probably do a gutter tap to (2) 100 amp single phase MB panels and (2) three phase service equipment rated discos for the a/c stuff.
> 
> Forget about balancing anything resi, even three phase. It will NEVER happen.


200 amps or less. I like this idea. 

I was also thinking of a 12-circuit three phase MLO and using a 60 amp breaker as the main disconnect. Is this a violation? I would like to use #6 copper. I know for inspection I would need to meet the requirements 408.36 (D). 



> Back-Fed Devices. Plug-in-type overcurrent protection
> devices or plug-in type main lug assemblies that are
> backfed and used to terminate field-installed ungrounded
> supply conductors shall be secured in place by an additional
> ...


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## Magnettica (Jan 23, 2007)

NolaTigaBait said:


> I know...JUst making sure we are on the same page...If you can't get that 60 space, it may be cheaper to just get a single phase panel(im assuming there are no mwbc's using 3 circuits) and then 2 disco's for the a/c's...
> 
> That large panel would really save time...I wonder what they cost?


I checked with Cutler-Hammer and with Square D. 

Neither offered 60-circuit 3-phase MB 150/ 200 amp. 

By the way, holy crap..... nearly $600 for a 30 circuit 150 amp MB panel?


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## BuzzKill (Oct 27, 2008)

Magnettica said:


> I
> 
> By the way, holy crap..... nearly $600 for a 30 circuit 150 amp MB panel?


who'd you call, Neiman-Marcus? :laughing:


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## NolaTigaBait (Oct 19, 2008)

Magnettica said:


> 200 amps or less. I like this idea.
> 
> I was also thinking of a 12-circuit three phase MLO and using a 60 amp breaker as the main disconnect. Is this a violation? I would like to use #6 copper. I know for inspection I would need to meet the requirements 408.36 (D).


I think you are good. #6 thhn?...I don' think that is for feeders, I believe that is for service conductors that are back fed...


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## MDShunk (Jan 7, 2007)

Magnettica said:


> I was also thinking of a 12-circuit three phase MLO and using a 60 amp breaker as the main disconnect. Is this a violation? I would like to use #6 copper. I know for inspection I would need to meet the requirements 408.36 (D).


That would be expensive, plus it will probably end up being a 20" panel. Cheaper to look for a couple enclosures for a single 3-pole breaker marked SUSE.


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## Magnettica (Jan 23, 2007)

Marc, the two service-rated disconnects for the AC's with circuit breakers are about how much each? I told the lady I'd get her a proposal tonight. 

$100 each maybe?


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## Magnettica (Jan 23, 2007)

BuzzKill said:


> who'd you call, Neiman-Marcus? :laughing:




Dude, seriously, the big boy electrical equipment is expensive.


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## BuzzKill (Oct 27, 2008)

Magnettica said:


> Dude, seriously, the big boy electrical equipment is expensive.


yeah I got a quote for gfi 20amp bolt-on breakers for $165+.


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## BuzzKill (Oct 27, 2008)

Magnettica said:


> Dude, seriously, the big boy electrical equipment is expensive.


I have a job right now that is very similar to yours and I know the stuff adds up, plus the client is a cheap-skate.


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## Magnettica (Jan 23, 2007)

BuzzKill said:


> I have a job right now that is very similar to yours and I know the stuff adds up, plus the client is a cheap-skate.


Fortunately, my client isn't very poor but that doesn't mean they aren't cheap. :whistling2:


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## BuzzKill (Oct 27, 2008)

Magnettica said:


> Fortunately, my client isn't very poor but that doesn't mean they aren't cheap. :whistling2:


It's replacing a 3phase bulldog disco that feeds two small 3phase loads and the rest is two 120/208 panels that don't have over-current protection of their own.


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## Magnettica (Jan 23, 2007)

BuzzKill said:


> It's replacing a 3phase bulldog disco that feeds two small 3phase loads and the rest is two 120/208 panels that don't have over-current protection of their own.


$3500 :thumbsup:


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## Cletis (Aug 20, 2010)

*How*

I think I'd use the top left 2" nipple and go right in a 100 or 150 amp 3 phase panel. That would get rid of those a/c disco's with the jbox then I'd use the 1.5 inch nipple on bottom and put in a 42 space single phase panel and get rid of rest of boxes and consolidate. I'd leave the trough and 2 nipples obviously.


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## Cletis (Aug 20, 2010)

*TM*

Material 1,450.00 

Labor 1,400.00

Total 2,800.00

1 man 8-10 hrs


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## slickvic277 (Feb 5, 2009)

Cletis said:


> Material 1,450.00
> 
> Labor 1,400.00
> 
> ...



How much you paying on the flat rate??


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## B4T (Feb 10, 2009)

Ron.. check out Murray (3) phase panels.. I use them all the time in single phase and the price can't be beat.. :thumbsup:


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## nitro71 (Sep 17, 2009)

Wonder if you could use the fused disconnect as your service disconnect and over current protection. Then feed a main lug three phase panel?


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## Cletis (Aug 20, 2010)

*FR*



slickvic277 said:


> How much you paying on the flat rate??


If I did it Flat Rate probably 1,900.00 


But, I wouldn't flat rate that one. I'd do it myself and make the whole 1,500 if I wasnt too busy. Those are the easiest money makers of all things and I love to do panel stuff like that. I only flat rate rewires, attic work, you know, general crappy stuff.


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## MDShunk (Jan 7, 2007)

nitro71 said:


> Wonder if you could use the fused disconnect as your service disconnect and over current protection. Then feed a main lug three phase panel?


Yes, but residential customers FREAK when they see fuses getting installed. One of the main primary motivations for service upgrades is to "get rid of fuses", because homeowners have the feeling that fuses are unsafe. This is important information to know when you're selling service upgrades and doing installs.


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## Magnettica (Jan 23, 2007)

Cletis said:


> If I did it Flat Rate probably 1,900.00
> 
> 
> But, I wouldn't flat rate that one. I'd do it myself and make the whole 1,500 if I wasnt too busy. Those are the easiest money makers of all things and I love to do panel stuff like that. I only flat rate rewires, attic work, you know, general crappy stuff.


So you'd do this service all time and materials? That's what you're saying to me or at least that is how I am interpreting it. I will be selling this one with a set rate in the neighborhood of $2200, and that's only for panels and grounding. This selling price does not include the exterior wiring because it's all in pretty decent shape.


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## Cletis (Aug 20, 2010)

*2,800*

No. My total price to them would be 2,800.00 

I'm thinking about 1,400 ish material 

the other 1,400 should cover labor, overhead, and all that business stuff. 

Those 3 phase breakers are expensive


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## JohnR (Apr 12, 2010)

I agree with Cletis, although my numbers may be slightly different.^


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## B4T (Feb 10, 2009)

I checked today.. a Murray (3) phase MB 100A goes for $260.00


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## nitro71 (Sep 17, 2009)

MDShunk said:


> Yes, but residential customers FREAK when they see fuses getting installed. One of the main primary motivations for service upgrades is to "get rid of fuses", because homeowners have the feeling that fuses are unsafe. This is important information to know when you're selling service upgrades and doing installs.


True but look at that pile of poodoo it replaces in this case. And the disconnect is existing. Was just an idear!


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## Magnettica (Jan 23, 2007)

I sent out the proposal tonight so we will see. I opted to use (1) 100 amp MB 120/ 208 30 circuit panel and (1) 100 amp MB 120/ 240 30 circuit panel. The trough I plan to put above these two panels needs to sit off the plywood board like 3/4" so that the romex home runs can be brought into the top of the panels. Offset nipples for the SEC's.


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## RePhase277 (Feb 5, 2008)

Magnettica said:


> I sent out the proposal tonight so we will see. I opted to use (1) 100 amp MB 120/ 208 30 circuit panel and (1) 100 amp MB 120/ 240 30 circuit panel. The trough I plan to put above these two panels needs to sit off the plywood board like 3/4" so that the romex home runs can be brought into the top of the panels. Offset nipples for the SEC's.


So one 3 ph. panel and one single ph. panel? Make sure to use a full size neutral on the 1-ph panel, because the neutral of a 3-wire 1-ph system tapped from a 4-wire 3-ph system carries as much current as the hots.


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## Hairbone (Feb 16, 2011)

Magnettica said:


> I sent out the proposal tonight so we will see. I opted to use (1) 100 amp MB 120/ 208 30 circuit panel and (1) 100 amp MB 120/ 240 30 circuit panel. The trough I plan to put above these two panels needs to sit off the plywood board like 3/4" so that the romex home runs can be brought into the top of the panels. Offset nipples for the SEC's.


why don't you punch out the wireway and put the romex in and have a nipple to the new panel to pull the wire through? It would take extra time, but would be a clean installation and you wouldn't have to extend a wire with a wirenut in the panel.


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## randas (Dec 14, 2008)

Magnettica said:


> Who makes the 60 circuit... CHCH?


Everyone makes them. We've been using them up here for years :thumbsup:

Heck I could even hook you up with a 80 cct federal if you want :laughing:


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## Hairbone (Feb 16, 2011)

randas said:


> Everyone makes them. We've been using them up here for years :thumbsup:
> 
> Heck I could even hook you up with a 80 cct federal if you want :laughing:


 
Just bolt one of these in place if money is no object:thumbsup::http://www.cpipanels.com/


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