[Ohio_Remodeler]

I would like to upgrade service panel at commercial location to accommodate 5 100-Amp Service Panels (4 Apts. & 1 House Panel) & 1 200-Amp Service Panel.

I asked about upgrading the service equipment a couple months ago and TK asked me to check with the utility company to get some answers before proceeding. TO answer his questions:
1. ringed or ringless meter sockets?
It's up to me (I do not know what the difference is - if someone could let me know I would appreciate it).

2. Location of meters?
The utility company has no problem with the service panels & meters being located inside.

3. Lever bypass?
A lever bypass is not required for small commercial.

I did some research and found a Cutler Hammer 6 meter pack with 200 socket amp rating, ring style, 6 meter sockets, 600 bus ampacity. Catalog Number is CH1MP6206R. After doing the load calculations, I feel comfortable with 600 amp.

http://images.i2content.net/MRO_imag..._4_5_6_5_8.pdf

1. Is this meter pack a good choice?

2. Will this ringed meter pack work with the meters shown?

3. Do the feeders going to the bottom 2 service panels need to be secured to the plywood or are they okay as is?

4. What gauge wire is coming into the current main disconnect? Will this work with a 600 Amp Meter Pack?

[tkrussell]

Really? The utilities I get to deal with are just short of dictators. One thing I do like about this forum is I get the benefit of learning how this industry is different in other parts of the country, and sometimes other countries. ( I get a kick out of the Ring Main system in the UK, very interesting system)

I like this utility you have, the customer has the choice! Can you let me know their name, I would like to check their installation requirements, they may be on line.


1. ringed or ringless meter sockets?

There is no difference in the actual meter, the difference is the meter socket, a ringed meter has a capture ring to retain the meter in place. A ringless meter uses the metal cover to capture the meter. Not sure why some utilities like either, my guess is their perception on the safety of one compared to another.Either is fine by me, get the less expensive.

2. Location of meters?
The utility company has no problem with the service panels & meters being located inside.

Service panels inside is typical, but most utilities,I thought want the meters outside to allow easy reading of the meter.The upside to this is the customer does not need to worry about access for the meter reader, the downside is the service disconnect(s) are exposed to vandals. Since you have a choice, I will let you decide.

3. Lever bypass?
A lever bypass is not required for small commercial.

Lever bypass allows the utility to remove and test meters, of course during normal daytime business hours (meter depts hours are from 9 AM until 2 PM, rough hours), without any disruption to a commercial business. I once put in a standard meter socket for only TWO light poles in a plaza, guess what, I HAD to install a lever bypass meter. Rules are rules I was told.

In your case I would not worry about it, use non lever bypass, it will be cheaper.

I did some research and found a Cutler Hammer 6 meter pack with 200 socket amp rating, ring style, 6 meter sockets, 600 bus ampacity. Catalog Number is CH1MP6206R. After doing the load calculations, I feel comfortable with 600 amp.

CH gear is fine. I would be interested in seeing how the calcs were done


1. Is this meter pack a good choice?

No problem, I use CH gear. Just a small piece of advice, no matter whose meter pack, or any new electrical gear, be sure all bolted connections inside are tight. Any quality electrician will never assume the factory tightened everything. Best to use a torque wrench to proper values. Really sucks trying to tighten something after it has been energized and put into operation, even worse to find there is a hot spot a year or two later that is damaging the gear.

2. Will this ringed meter pack work with the meters shown?

They appear to be fairly new, again the difference is the meter socket not the meter.

3. Do the feeders going to the bottom 2 service panels need to be secured to the plywood or are they okay as is?

Sorry but I really don't see the feeders you are referring to, (I cringe when I see these pictures). Any cable or conduit has it's requirement for supporting, need to look up in the code the wiring method being used , AC Cable (AKA BX), MC, Nonmetallic cable (AKA ROMEX), EMT, etc.

4. What gauge wire is coming into the current main disconnect? Will this work with a 600 Amp Meter Pack?

Sorry, pictures may tell a thousand words, but not in this case. I see aluminum wire at the top left hot line lug, appears to be XHHW insulation XHHW has a distinct dull shine, and my guess is 250MCM wire. I see the conduit bushing is doing a lot of good, sorry just nitpicking.

I can tell this is a 200 amp fused disconnect switch, 250MCM Al is the correct size wire for a 200 amp service.

Are you asking if the 200 amp feeders are sufficient to feed a 600 amp service? I think you know that answer.

There are a few options, a typical 600 amp service entrance feeder size can be parallel 500 MCM XHHW wire, that means two 500 MCM wire for each hot and the neutrals, for a total of 6-500MCM wires in one conduit out to the utility point of attachment.

These 6 wires will fit in the minimum of 3-1/2" IMC,GRC,PVC Sch 40, or 4" PVC Sch 80.

Just a note, the six meter pack setup will act as the building's service disconnecting means using the Six Switch Rule, See NEC 230.71, which is fine.

If there is ever the chance another meter will be needed in the future because of another tenant, one 600 amp main switch will be needed to be added. This will not be easy and cheap to do later on, just something to consider.

[Ohio_Remodeler]

Thanks for the quick response, I may have a couple additional questions as I have electricians come out to bid the job.

[InspMO]

I am new to this discussion board, I am a construction inspector. Ohio you need to call a licensed electrical professional. That picture is... let's say interesting! LOL

[Ohio_Remodeler]

I've had 4 electricians come out for estimates this week. Apparently this is a pretty unorthodox setup because they kept saying things like "never seen a setup like this before." They were also in a state of disbelief when I told them the utility company is the one who put the meters in and left the lugs on the meters exposed.

Anyway, I just want to confirm that I've got the setup planned correctly before I hire the electrician.

1. The existing riser will be replaced with 3-1/2" PVC Schedule 40.
2. The 600 Amp service entrance feeder will be 6 500 MCM XHHW wires.
3. The service equipment will be a Cutler Hammer 6 meter pack with 200 socket amp rating, ring style, 6 meter sockets, 600 bus ampacity. This equipment is going to service 5 100-Amp service panels and 1 200-Amp service panel.
4. The 100-Amp service panels will be supplied by 2-2-2 SE Aluminum. The 200-Amp service panel will be supplied by #4/0 aluminum. Do these wires need to be in conduit or are they okay just in the sheathing?

One of the electricians told me that there would need to be a main disconnect before the 6 gang meter pack. I told him that there would be a main disconnect in the 6 gang meter pack so that would function as the main disconnect per the six switch rule that TK stated earlier. Just want to confirm that no main disconnect switch has to go before the meter pack.

[tkrussell]

Just a couple of comments:

An unorthodox setup is putting it mildly.

Be sure the #2 Se cable to the 100 amp panels is SER cable, 4 wire.

#4/0 Al is only allowed for 200 amp Residential, and I believe the 200 amp panel is a commercial occupancy, so 250 MCM is the minimum size Aluminum wire allowed.

The wire ampacity is per Table 310.16 75Deg C Column,since none of the gear going in will have terminals rated 90Deg C. #4/0 is only rated 180 amps.

If you look at Table 310.15(B)(6) is where #4/0 is allowed for 200 amp residential only. And technically , only for Single Family Dwellings, so the #2 is too small for the apartments also.

SE cable, either SEU(3 wire) or SER(4 wire), is intended to be installed without conduit, except where subject to physical damage, and this is unlikely and not a concern here.

As I stated previously:
Just a note, the six meter pack setup will act as the building's service disconnecting means using the Six Switch Rule, See NEC 230.71, which is fine.
Unless a main is required by local,state or utility code, which I doubt.

Only one out of 4 said a Main is needed, so seems there is no local code,otherwise the other three should have mentioned it, seems he should not the one to get the job. Good time to educate him so he can get the next job like this.

[Ohio_Remodeler]

I sent the following specs to an electrical contractor to bid this job.


Install CH1MP6206RRL Meter Pack in basement

Demo existing riser & replace w/ 3.5" PVC Schedule 40

Upgrade wire from masthead to meterpack (200-Amp now) to 600-Amp wire (500 MCM XHW - 6 Wires)

Demo existing #6 wire going to 4 service panels & demo 125-Amp wire going to retail panel

Demo main disconnect and box containing 8 60-amp fuses

Reuse existing 5 service panels

Install 5 retaining kits (1 in each service panel)

Install house service panel (100-Amp) next to existing service panels - I already have this 100-Amp service panel, it just needs to be secured to plywood in basement

Relocate 4 meters currently in basement to meter pack

Run SER 4 Wire from Meter Pack to each service panel (Enclose in conduit if required by code) - 5 runs - 100-Amp Panels

Run 250 MCM Wire - 1 run - 200-Amp Retail Panel

Order 2 meters from City of Columbus Electric & install in meter pack (One for Unit B which is currently missing meter & one for house panel)


He emailed back with the following:

I can follow this if you want me to. However, we can cut cost with the wire using 3 X 500 MCM for the entrance because we can derate it to 55%, for a multiple occupancy building, then we can reduce the size of the entrance conduit too, I think down to 2". Also, we can use 4/0 for the 200 Amp entrance because it is the within 5% of the 200 amp ampacity and it's the next common breaker size by code. I will try to save you some money anywhere I can.

The main issue I see here is getting the conduits from the meter pack to the panels. We will have 20 X #2 wires and 4 X #4/0's and 1 X #4 if we run them in individual conduits. I believe if we update the entrance wire we will have to have the meter pack mounted outside for AEP. We should get the rough in inspection for the inside and check with the inspector how he wants it done.

I will need to see inside again to check the runs from/for the meter pack.


I'm not educated enough to know if what he's proposing is viable. Please let me know if his idea is a good one as I like saving money. Incidentally, I have a different electrician who is fine doing it the way I specified.

[Ohio_Remodeler]

I forgot to ask this: Since TK stated conduit isn't used for SE cable in this situation, why is this electrician concerned about getting the conduits from the meter pack to the panels?

[tkrussell]

Last question first, sounds like pulled indivdual wires in conduit is being proposed insteand of SE cable.

As far as the size service, still goes to calculated connected load, remember me saying you have a 200 amp, may need a 400 amp or maybe even 600 Amp? I do not know how it was calculated to arrive at 600 amp. Remember me asking I would like to see how the calcs were done?

As far as derating, I know that a feeder for 3-5 apartments can be derated by 45%, stores need to be 100 % since most stores run more than 3 hours. I am not aware of any derating allowed for multiple occupancy in the NEC.

Have any of these electricans done the service calculations? Or is this service size being guessed at? If you are asking contractors for a specific scope of work, they are probably just quoting on it assuming the sizes are correct, and not doing what they should be doing, collecting all the load data and performing the calcs themselves. Or at least asking who did the calcs, how were they done.

As far as the #4/0 Al for 200 Amp, I have never heard of the 5% of a rating and I can bump up to next size. Table 310.16, 75Deg C column ,the highest temp rating allowed for these terminals,#4/0 Al is rated 180 amps, allowed for a 200 amp residential feeder only. So I do not know where he is coming from on this.

Even thou most inspectors will not help to design electrical systems, not their job, it may be worth a try to find out what his interpretation is on some of these suggestions.

Keep in mind the electricians are to be doing the sizing and rating calcs ,not you. Upside is onec they file for permit, they may not be aware of it, but the installing contractor is ultimately responsible.