Residential 3 Phase Panel

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Aledrell

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In older neighborhoods we run across 3-phase residential panels that require change out due to age or whatever. Typically the AC is the only item requiring use of the third phase. Back in the day they used delta breakers to accomplish this task cheaply. I am curious to know how are you guys are cost effectively changing out 3 phase panels, because the cost of these panels is high, yet mainting code integrity and satifing utility requirements. The utility requires total disconnections mean on the load side of the meter such as MB or fused disconnect. I was thinking about using a 3 phase meter base to a load center with a 200 amp MB the cost for this without branch breakers is $650. Any cheaper way of accomplishing this? Thanks.
 
what if you put parallel lugs on the 3-phase meter base take the 3 phases to a small disconnect just for the ac and take 2 of the phases to a 200 amp single phase panel?
 
nunu161 said:
what if you put parallel lugs on the 3-phase meter base take the 3 phases to a small disconnect just for the ac and take 2 of the phases to a 200 amp single phase panel?
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Or a line gutter.
I usually set up a three phase equipment panel and then a single phase panel for the rest of the loads.
A house that has a three phase panel in this area is usually over five thousand square feet. Not the type of client that would, in their right mind, decline spending a few hundred extra bucks on a panel if you could properly explain to them the reason they need it.
 
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parallel lugs, 200 amp QO squareD single phase panel and a 3-phase 30 amp disco.,should cost you around 315, not sure about the meter but thats needed regardless, thats the cheapest way i can see doing this with minimal labor, installing a gutter would need a little more work
 
nunu161 said:
what if you put parallel lugs on the 3-phase meter base take the 3 phases to a small disconnect just for the ac and take 2 of the phases to a 200 amp single phase panel?
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That's what I've done. MB panel for building, ML for 3ph AC unit.
 
jrannis said:
A house that has a three phase panel in this area is usually over five thousand square feet. Not the type of client that would, in their right mind, decline spending a few hundred extra bucks on a panel if you could properly explain to them the reason they need it.
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It is very unlikely you'd get a high-leg service if you requested a 3ph service these days; you/d more likely receive a 208Y/120.
 
Twoskinsoneman said:
Is this to say the AC disconnect has to be grouped with the main and therefore you couldn't, say use a MBP inside?
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I'm not saying that you can't use a MBP inside.
The Main must disconnect all of the power going to the dwelling, and if you use more than one disconnect to accomplish this (up to 6 handles), they must be grouped together per 230.72(A)

Since you would have to operate two different switches (the inside MBP and the Disconnect for the AC ) to disconnect power to the dwelling, both disconnects would be part of the MAIN.
As such, they must be grouped together.

Just my opinion
steve
 
every 400 amp residential service i have ever done ive used two seperate 200 amp MBP's both being fed directly from the meter. Do they actually have to be in the same enclosure or can you consider them grouped if they are right beside each other?
 
nunu161 said:
every 400 amp residential service i have ever done ive used two seperate 200 amp MBP's both being fed directly from the meter. Do they actually have to be in the same enclosure or can you consider them grouped if they are right beside each other?
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right beside each other is acceptable.
 
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