400 Amp 3 phase service ?

[tbakelis]

Hello,

Summary:

I'm new to this site and have been a licensed electrician for 5 years. I've done mainly residential with limited commercial work. I have a customer who I have done residential work for who owns a 2 unit commercial property that has 100 amps / 3 phase servicing each unit. One unit is a Deli and will remain as is... but the other unit is going to be leased to a Yogurt shop that has done load calcs and will require a 400 Amp / 3 phase service. The utility company says that it can bring only 3 phase 120/240 volts with High leg (stinger) to the building via underground.

Now my questions:

1.) Any suggestions on what products (square D, siemens...) would work best in this scenario?
2.) I'm assuming that the utility feed will go into a meter/can from which 500 kcmil will feed a load center? OR into a meter/can from which 2 - 200Amp breakers/disconnects will feed two separate 200 Amp load centers?
3.) Ground wire size? Ground rod?

I figure this will be a good learning experience, I just need to get going in the right direction.

Hope I haven't offended anyone with my lack of knowledge.

Any help will be greatly appreciated.

Thanks,

Ted

 

[augie47]

Welcome to the madhouse.
I think your first step would be additional info from POCO. Some use CT's for such a service, some enclosed meters and some want a cold sequence
switch ahead of the metering so you need to meet their needs first.
With a "high leg" service you might want to consider a panel for the three phase loads and a second for the single phase. Using one panel might reduce the 120v breaker availability since 1/3 of your panel would not be available for 120v loads. (The decision would depend on how many 3 phase loads you have)
As far as grounding, you need to determine your point of connection and size per 250.66 at that point. If you are grounding from the 400 amp meter, etc it would be a 1/0 (except #6 to rods and #4 to CEE). If you split to two panels and ground from them, probably a #4

 

[bob]

One unit is a Deli and will remain as is... but the other unit is going to be leased to a Yogurt shop that has done load calcs and will require a 400 Amp / 3 phase service. The utility company says that it can bring only 3 phase 120/240 volts with High leg (stinger) to the building via underground.


Ted

Who did the load calculations? I can't imagine a yogurt shop having that much load.

 

[nakulak]

the yogurt shop should have some plans ?

 

[roy g]

roy g

roy g

the utilitys in our area require CT's on 400 amp. I'm not sure if a 400 amp base is available for 3 phase. Normally in a case such as you describe, we would come out of CT cabinet and hit the 2 200 amp panels with 3/0 and # 4 ground. the inspectors and utility in this area want all grounding tied back into the CT cabinet. I would make one single phase if the other would carry the 3 phase load. We did a subway recently which required a 400 amp service. the load was no where near that.

 

[Sierrasparky]

400 amps
That's some yogurt shop.
How many yogurt machines do they have. 20.....30..
I've wired a whole restaraunt with 400 amps.

 

[tbakelis]

1. The load calc was done by the new tenants electrician... I'm just suppose to provide the new 400 Amp service and the tenants electrician will do the rest. These are the main KVA's that they have

Ice Maker 3.4 KVA
Cooler 1.2 KVA
Gelato 2.2 KVA
Counter 1 KVA
Soft Serve Freezer 11.2 KVA
Soft Serve Freezer 11.2 KVA
Soft Serve Freezer 11.2 KVA
Soft Serve Freezer 11.2 KVA
Soft Serve Freezer 11.2 KVA
AC Unit 12.4 KVA
And about another 15 KVA for lights & Recep

2. Stupid question... what does CT stand for?

3. If anyone lives in the San Jose, CA Bay Area, I'm willing to do the job with them

Thanks everyone and looking forward to more in the future.

Ted

 

[augie47]

Looks like 400 isn't a bad idea. Assuming whats 3 phase, I'd probably go with a 200 or 225 3 phase panel and a 200 single phase, but you could compare cost.
CT is the type metering where the power goes thru current transformers which run the meter.
Again you need to talk with the power co. and check their requirements and determine what they are going to do. In this situation some POCO's require you to run your wiring all the way to their transformer, some to a junction point and some to a CT cabinet.
Since this is your first your idea of teaming up is probably good.

 

[bob]

The load calc was done by the new tenants electrician... I'm just suppose to provide the new 400 Amp service and the tenants electrician will do the rest

OK. Then 400 it is.