# 600 amp service to a new 5 meter can



## wrkhrdplyhrd

Looking for a little help determining how I'm going to set up this install. I've been doing resi electrical work for 20+ years, and I've done a thousand 200amp service changes/upgrades overhead and underground services, and plenty of the home wiring, but this project will be a first for me and is maybe considered more on the commercial side of things. 

The project is in Southern California, a 4 unit apartment which currently has a single 100amp main panel with a single meter. From the existing main, a single large romex feeds into the laundry room to a distribution panel, which then breaks everything down and sends power to each unit (each unit has 3 or 4, 15 & 20 amp breakers). 
The owner simply wants to separate the service so his tenants can start paying their own elec bills instead of him having to pay it every month. (Seems silly to me, he could just raise the rent.....but I'm not going to talk myself out of a job)

So, I'm looking at installing a surface mount, overhead feed, 5 meter can (1 for each unit + a 'house' meter) with 600 amp service....(each main breaker slot is rated to 125 amps, so the whole panel is 600 amps). I only plan to install 50 amp main breakers for each unit and the house meter, but I was told that since the panel is rated to 600 amps, I'll have to supply it with 600 amp service in case somebody down the road wants to upgrade their main breaker. I'm fine with all that....

My question/s starts with, what size feeders am I going to need? I'm getting/hearing conflicting answers all over the place. The best I can figure is parallel 350mcm feeders....or can I use 300's instead to save a little money? 
After figuring that out, my next question is what size riser conduit will I need in order to fit all those feeders? Can I fit all that into a 4" conduit, and if so, will I actually be able to bend those wires tight enough to come out of the service head (without breaking the head), and with all those current carrying conductors in the same conduit, do I need to worry about derating? Or is better/smarter to run two 2.5" risers (or 3" risers) with 3 feeders in each? 

Lastly, reviewing the code book, it looks like I'll be ok with a #2 ground wire....table 250.66 says #2 copper ground, for feeders up to size 350....but I've also been told to use #1.....? So I'm getting confused. 

Obviously with the high cost of these of materials, I can't afford to make a mistake and have the inspector make me change something.....So I'm reaching out for some help. 

Thanks in advance.


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## Cow

How are you getting around 230.79(C)?


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## manchestersparky

Cow said:


> How are you getting around 230.79(C)?


230.79(C) is for a one family dwelling ( single family home)

The OP is dealing with a 4 unit apartment building which is a multifamily dwelling


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## Cow

manchestersparky said:


> 230.79(C) is for a one family dwelling ( single family home)
> 
> The OP is dealing with a 4 unit apartment building which is a multifamily dwelling


Is there any minimum for a multifamily, would part (D) come into play then?


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## manchestersparky

Cow said:


> Is there any minimum for a multifamily, would part (D) come into play then?


A multifamily dwelling has 3 or more dwelling units

From Article 100 - Definitions

Dwelling, One-Family. A building that consists solely of one dwelling unit.
Dwelling, Two-Family. A building that consists solely of two dwelling units.
Dwelling, Multifamily. A building that contains three or more dwelling units.
Dwelling Unit. A single unit, providing complete and independent living facilities for one or more persons, including permanent provisions for living, sleeping, cooking, and sanitation.


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## bostongtp

wrkhrdplyhrd said:


> Looking for a little help determining how I'm going to set up this install. I've been doing resi electrical work for 20+ years, and I've done a thousand 200amp service changes/upgrades overhead and underground services, and plenty of the home wiring, but this project will be a first for me and is maybe considered more on the commercial side of things. The project is in Southern California, a 4 unit apartment which currently has a single 100amp main panel with a single meter. From the existing main, a single large romex feeds into the laundry room to a distribution panel, which then breaks everything down and sends power to each unit (each unit has 3 or 4, 15 & 20 amp breakers). The owner simply wants to separate the service so his tenants can start paying their own elec bills instead of him having to pay it every month. (Seems silly to me, he could just raise the rent.....but I'm not going to talk myself out of a job) So, I'm looking at installing a surface mount, overhead feed, 5 meter can (1 for each unit + a 'house' meter) with 600 amp service....(each main breaker slot is rated to 125 amps, so the whole panel is 600 amps). I only plan to install 50 amp main breakers for each unit and the house meter, but I was told that since the panel is rated to 600 amps, I'll have to supply it with 600 amp service in case somebody down the road wants to upgrade their main breaker. I'm fine with all that.... My question/s starts with, what size feeders am I going to need? I'm getting/hearing conflicting answers all over the place. The best I can figure is parallel 350mcm feeders....or can I use 300's instead to save a little money? After figuring that out, my next question is what size riser conduit will I need in order to fit all those feeders? Can I fit all that into a 4" conduit, and if so, will I actually be able to bend those wires tight enough to come out of the service head (without breaking the head), and with all those current carrying conductors in the same conduit, do I need to worry about derating? Or is better/smarter to run two 2.5" risers (or 3" risers) with 3 feeders in each? Lastly, reviewing the code book, it looks like I'll be ok with a #2 ground wire....table 250.66 says #2 copper ground, for feeders up to size 350....but I've also been told to use #1.....? So I'm getting confused. Obviously with the high cost of these of materials, I can't afford to make a mistake and have the inspector make me change something.....So I'm reaching out for some help. Thanks in advance.


So your looking how to size this Multi family dwelling?? 100a service to a 600a service seems Ludacris. What made you decide on that?? Lots of money can be saved there. That's a lot of upgrade, he will NEVER even come close to this, in my opinion, and I don't even know the dimensions. LET ME CLEAR I'm not insulting you, I haven't done many of these but I'll throw out my ideas hopefully they aren't useless.

What are the dimensions of the house, what type of appliances gas or electric? 
Mike Holt:

Step 1- determine general load. Consists of general lighting and receptacles (3va per sq ft), you can forget about laundry load if there's a central facility nec 210.52 (f))
Step 2- Determine A/C vs Heat (both won't run at same time, you can omit the smaller of the 2 loads.
Step 3- Determine you appliance demand Load ( NEC 220.17). 
Step 4- Determine Clothes dryer Load (NEC 220.17) (Demand factors in 220.18)
Step 5- Determine cooking equipment loads (NEC 220.19)

Step 6- Size Feeder and Service conductors. Add up all your loads, if the load is greater than 400a size the UNGROUNDED conductors at table 310.15 (b)(6) for 120/240 single phase. If it's over 400a size the UNGROUNDED conductor at 310.16

Hope some of this helps, I'm not to thank, Mike Holt is. Check him out.


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## chicken steve

Ok, you've an apartment full of welders...:jester: who am i to pick apart a job?

but you're probably going to find you'll need the gangable style meter packs, with an entry can rated for it all

2----3" pipes w/500kcmil al (if you went al) would need to make in somewere, not gonna happen on a milbank 6 pack...

~CS~


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## bostongtp

chicken steve said:


> Ok, you've an apartment full of welders...:jester: who am i to pick apart a job? but you're probably going to find you'll need the gangable style meter packs, with an entry can rated for it all 2----3" pipes w/500kcmil al (if you went al) would need to make in somewere, not gonna happen on a milbank 6 pack... ~CS~


What do you think about the 100-600a service upgrade Steve??


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## chicken steve

bostongtp said:


> What do you think about the 100-600a service upgrade Steve??


Probably unnecessary , and what do you want to bet the poco _(realizing no load change)_ will run it off the same drop/xformer :whistling2:

But hey, if the customer wants it, give it to him/her!

~CS~


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## MDShunk

I've done many multi-family apartment gang meter installs where each unit was served by a 30-amp breaker. :thumbsup:


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## bostongtp

chicken steve said:


> Probably unnecessary , and what do you want to bet the poco (realizing no load change) will run it off the same drop/xformer :whistling2: But hey, if the customer wants it, give it to him/her! ~CS~


 Aha ha, I didn't even think of that.

Wrkhrd, I'm not contesting anything you want to do, give him what he wants, just know your options.


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## Pharon

A 200A upgrade seems more than sufficient here, especially if you're only feeding each unit with 50A.


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## chicken steve

chicken steve said:


> Ok, you've an apartment full of welders...:jester: who am i to pick apart a job?
> 
> but you're probably going to find you'll need the gangable style meter packs, with an entry can rated for it all
> 
> 2----3" pipes w/500kcmil al (if you went al) would need to make in somewere, not gonna happen on a milbank 6 pack...
> 
> ~CS~


I'm _wrong_ 

Milbank does make a 5/6 pack 600A buss>









and you can stuff a lotta 350CU Xhhw in a 4" down to it

they sell the dual lugs too

_mea cuppa!_
~CS~


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## ElectricJoeNJ

I don't think his intention was to do an upgrade to 600 amps. He might be forced to run 600 amp feeders because of the rating of the stack. What I would do is do a 200 amp service to a 200 amp fused disco and run the 5 Meter stack on the load side of the disco.

Edit. I don't think this is considered commercial. If its a standard 3 wire 120/240v service than 310.15b7 would apply for sizing the feeders


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## wrkhrdplyhrd

ElectricJoeNJ said:


> I don't think his intention was to do an upgrade to 600 amps. He might be forced to run 600 amp feeders because of the rating of the stack. What I would do is do a 200 amp service to a 200 amp fused disco and run the 5 Meter stack on the load side of the disco.
> 
> Edit. I don't think this is considered commercial. If its a standard 3 wire 120/240v service than 310.15b7 would apply for sizing the feeders


ElectricJoeNJ.....You're right. I never wanted to upgrade to 600amp service. It's serious overkill (considering the building currently only has 100amp 240v service and has for 20+ years without problems, and no additional loads are being added). The new main panel I was considering was rated to 600amps and I was told, that being the case I would have to feed it with 600amp service. I want to get away from that if I can. I'd prefer to just go with a 'standard' 200 amp service using 2/0 or 3/0 feeders (I'm not clear if I can use 2/0 and consider this a residential install or if I need to go to 3/0 for a commercial install) and a #4 ground. 

I'm just having a hard time finding the right hardware set up. I deal primarily with all-in-one panels usually 200amps. I'm finding all sorts of panels with 4 meter sockets or less, but I'm having a hard time finding anything with 5 meters, that isn't rated at and requiring the 600amp service. 

I was thinking of running my new riser straight into a horizontal gutter (maybe a bussed gutter), and then coming off the bottom side with 5 off-set nipples straight down into 5 individual meter sockets (http://www.homedepot.com/p/Square-D...H=REC-_-product-1-_-203495095-_-100141763-_-N), then routing my 4-wire, 240v, 50 amp home runs to the from there, straight to the individual sub panels approx. 50' away in the laundry room, and installing 50amp mains in each those panels. 
You see anything wrong with that set up? Or is there a better method you can suggest? 

My Other thought is the same as above, but rather than individual meter sockets, I'd install 5 separate 100amp all-in-one panels, but change out the 100amp main breakers and install 50amp mains. Then I'd just re-feed the old/existing circuits in the laundry room from there as needed.


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## ElectricJoeNJ

wrkhrdplyhrd said:


> ElectricJoeNJ.....You're right. I never wanted to upgrade to 600amp service. It's serious overkill (considering the building currently only has 100amp 240v service and has for 20+ years without problems, and no additional loads are being added). The new main panel I was considering was rated to 600amps and I was told, that being the case I would have to feed it with 600amp service. I want to get away from that if I can. I'd prefer to just go with a 'standard' 200 amp service using 2/0 or 3/0 feeders (I'm not clear if I can use 2/0 and consider this a residential install or if I need to go to 3/0 for a commercial install) and a #4 ground.
> 
> I'm just having a hard time finding the right hardware set up. I deal primarily with all-in-one panels usually 200amps. I'm finding all sorts of panels with 4 meter sockets or less, but I'm having a hard time finding anything with 5 meters, that isn't rated at and requiring the 600amp service.
> 
> I was thinking of running my new riser straight into a horizontal gutter (maybe a bussed gutter), and then coming off the bottom side with 5 off-set nipples straight down into 5 individual meter sockets (http://www.homedepot.com/p/Square-D-by-Schneider-Electric-100-Amp-Individual-Meter-Socket-UHRS111C/100141763?MERCH=REC-_-product-1-_-203495095-_-100141763-_-N), then routing my 4-wire, 240v, 50 amp home runs to the from there, straight to the individual sub panels approx. 50' away in the laundry room, and installing 50amp mains in each those panels.
> You see anything wrong with that set up? Or is there a better method you can suggest?
> 
> My Other thought is the same as above, but rather than individual meter sockets, I'd install 5 separate 100amp all-in-one panels, but change out the 100amp main breakers and install 50amp mains. Then I'd just re-feed the old/existing circuits in the laundry room from there as needed.


Your first option won't work because you have no OCBD on your feeder to the sub panel from each socket. Honestly the easiest and cleanest would be to install a 200 amp fused disco ahead of the 5 socket meter stack. Feed it with 2/0


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## backstay

Just because your meter equipment is rated for 600 amp doesn't mean you have to feed it with that. I install 125 amp MLO panels all the time that are fed with smaller feeders. It's about the load.


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## chicken steve

backstay said:


> Just because your meter equipment is rated for 600 amp doesn't mean you have to feed it with that. I install 125 amp MLO panels all the time that are fed with smaller feeders. It's about the load.


Yeah but, doesn't 690 dictate component(s) ratings for you to _have to_ do that Backstay?

~CS~


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## Shockdoc

chicken steve said:


> I'm wrong
> 
> Milbank does make a 5/6 pack 600A buss>
> 
> and you can stuff a lotta 350CU Xhhw in a 4" down to it
> 
> they sell the dual lugs too
> 
> mea cuppa!
> ~CS~


All the limo milbanks with 4 or more meters have dual 4" hubs on top.


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## NacBooster29

Why do you need 600 amp rated ? 
I would consider doing an actual load calc. 
A lot of municipals want that now anyways. 
You can get a 4 position meter stack with breakers sized appropriatly to each unit. 
You won't need to add all the breakers up to size your service. That would be crazy.


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## dronai

NacBooster29 said:


> Why do you need 600 amp rated ?
> I would consider doing an actual load calc.
> A lot of municipals want that now anyways.
> You can get a 4 position meter stack with breakers sized appropriatly to each unit.
> You won't need to add all the breakers up to size your service. That would be crazy.


 He said he needs 4 meters plus a house meter (5) total yes ?
I think he is saying he can't find anything with less than 600A busing in that size.


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## Shockdoc

House meter 100 amp continuous rating
Each unit 60 amp 80% unless all electric appliances
4x60=240 less 80%=180 amps
300 amp riser, one set 500mcm AL.


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## backstay

chicken steve said:


> Yeah but, doesn't 690 dictate component(s) ratings for you to have to do that Backstay? ~CS~


No, if I'm putting in a sub panel that needs a 100 amp feeder, I can put in a 200 amp panel, or any size 100 amp and up. It's about load, not load rating.


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