Advice needed: Swapping two 100 amp panels for two 200 amp panels

[unclejunk]

As the title states - I would like to swap out two 100 amp panels for two 200 amp panels in my two-family house to make wiring extra outlets easier, and also so that I can run a good amount of power to the detatched garage (the main reason).

I WILL be consulting an electrician before I do ANY electrical work; I just like to research things before I hire or ask anyone for help.

So my questions are... Do I need to have someone replace the service entrance cable(s) in order to be safe/legal/legit? Also - a friend mentioned that I might need bigger meters. Do they make 100 amp and 200 amp meters? And how can I tell which ones I have?


Information on what is currently at the house between the circut breaker panels and the incoming power line:

- The wire from the weatherhead to the two meters was recently replaced (within the last 2 years, but before I owned the house). It is about 30 feet long from the weatherhead to the meter box and is labeled:
NEXANS-C ENERGEX 8000 TYPE SE - STYLE: U 600V AA-8000-AL 2/C 4/0 AWG + 1/C 2/0 AWG (UL) E-49786
(I found the spec sheet for this wire here: nexans.us

- The two wires from the two meters to the 100 amp panels both look like they were replaced also. They look to be less than 10 feet in length and are both labeled:
KINGWIRE AA-8000 AL TYPE SE CABLE STYLE U XHHW-2 600 VOLTS 2CDRS #2 1 CDR#4 E73061 (UL)

- I live in Upstate NY (not sure if that matters).

Let me know if there is anything else you need to know... Any help/information you can give me is greatly appreciated! Thank you!

 

[Gary S]

I"m not an electrician, but going on my previous experience, yes, you need to replace the wires feeding the box. Some years ago I replaced a 100A box with a 150A box. I hired an electrician to do the work. He replaced the wire from the meter into the house to the new box with heavier wire rated for the 150A box. The electric company came out at the same time and pulled the meter for him to work, and put a meter back in when he finished. I don't know if they put in a heavier duty meter or reused the same one.

 

[bdog]

Weatherhead to meter:

4/0 AL is good for 200 amps. You are wanting to put 400 amps on it so it needs to be bigger.

Meter to panels
#2 AL is good for 100 amps. You are wanting to put 200 amps on it so it needs to be bigger.

 

[unclejunk]

Weatherhead to meter:

4/0 AL is good for 200 amps. You are wanting to put 400 amps on it so it needs to be bigger.

Meter to panels
#2 AL is good for 100 amps. You are wanting to put 200 amps on it so it needs to be bigger.

That is exactly what I needed to know. I realized that the wires are rated for 200 amps and 100 amps respectively, but wasn't positive if it would be within code.

It makes sense that I'd need wire capable of 400 amps if the maximum potential amperage is 400 amps, but the panels would never be at full 400 amp load... so I was thinking it might be OK as far as electrical code is concerned.

Thanks for the input!

 

[mrb]

you will also need to consult your power company (and pull a permit from your building department) before beginning this work.

 

[DURAMAT]

Power companys have their own set of codes they go by when pulling in their cable to the meters. I found it comical that my jobs would require such large conductors (according to our code) then they would come in and feed us with something that was more than half the size of what we pulled.

Do you really need 4/O? just because your putting in 2 200A panels doesnt necessarily mean you need to size your wire to it. I like putting in 200A panels just because I have room to expand my circuits or have more control of my circuits. But Realistically will I never ever come close to even drawing that amount that the panel is rated for. Mabe a quarter of that at best. Regardless, if you do end up using the existing wire from your meter, that will ultimately be your limit as to what your breaker will be supplying. Are you wanting two meters?

 

[Charles (in GA)]

Detached garage, you will only be able to run one feed to it to supply a sub panel in the garage. You cannot run multiple branch circuits to the detached garage, not allowed by code.

If you do not have a disconnect at the meter or before the panels, you will have to get the PoCo to pull the meters so you can do the work. They will most likely require you get permits and inspection before restoring power.

The #2 AL is good for a 100 amp service to a residence. (NEC 310.15(B)(6) ) If the panels will have main breakers larger than 100 amp, you will need the meter to panel cables/wires replaced.

Charles

 

[mrb]

he said its a two family house (duplex) so that would explain the two meters

 

[Charles (in GA)]

he said its a two family house (duplex) so that would explain the two meters

Missed that. Thanks. "Now I see" says the blind man.

Charles

 

[dugger10]

As far as needing two meters that depends on the load your gong to pull. Most likley you won't need and your really don't want the larger meters. Loads exceeding 200 amps generally need whats know as a Demand meter and the bills are ussually higher, sometimes much higher. They determine the kilowatt hour use and also the peak in 15 minute incriments measured by the meter. You'll pay for the kilowatt hours used plus a demand charge for the entire month based on the highest demand reading recorded by the meter. Its charged that way because utility company's must have transformers large enpough to serve your load, if you only use the peak in one 15 minute time period thats the rate you'll pay for the entire month. They will determine what you need after you provide them with a load sheet. Most likley your OK but I won't tell them your adding a bunch of load, wire out for 200 amps per meter and you should be fine. Sounds like all your really doing is adding space for additional circuits anyway, not really much added load except for plugs and lights. Anyway I hope this helps, good luck and be safe.

 

[Aceman]

As far as needing two meters that depends on the load your gong to pull.

No, it doesn't. It's a duplex, he needs two meters.

As the title states - I would like to swap out two 100 amp panels for two 200 amp panels in my two-family house!

 

[mrb]

As far as needing two meters that depends on the load your gong to pull. Most likley you won't need and your really don't want the larger meters. Loads exceeding 200 amps generally need whats know as a Demand meter and the bills are ussually higher, sometimes much higher. They determine the kilowatt hour use and also the peak in 15 minute incriments measured by the meter. You'll pay for the kilowatt hours used plus a demand charge for the entire month based on the highest demand reading recorded by the meter. Its charged that way because utility company's must have transformers large enpough to serve your load, if you only use the peak in one 15 minute time period thats the rate you'll pay for the entire month. They will determine what you need after you provide them with a load sheet. Most likley your OK but I won't tell them your adding a bunch of load, wire out for 200 amps per meter and you should be fine. Sounds like all your really doing is adding space for additional circuits anyway, not really much added load except for plugs and lights. Anyway I hope this helps, good luck and be safe.

as someone else said, he needs two meters because there are two dwelling units. You cant have two meters for one house even if you wanted (except for situations where the poco meters electric heat seperately, things like that). Furthermore I have never heard of a demand meter on a residential account (they may exist, if so please post a link to the poco so I can read up on it). Around here demand meters are placed on commercial accounts using 5,000kwh per month or more.

i know someone with a 15,000sq/ft house with an 800 amp service, and even he doesnt have a demand meter.

 

[JBurgess]

(they may exist, if so please post a link to the poco so I can read up on it).

Like this:

http://www.aps.com/_files/rates/ect-2.pdf

 

[JBurgess]

Not a demand charge, but you gotta love this one. It has terminal where you pre-pay on the wall and lights out when your payment used up.

http://www.srpnet.com/payment/mpower/Default.aspx

 

[mrb]

Like this:

http://www.aps.com/_files/rates/ect-2.pdf

thats optional. most pocos have some sort of optional time of use / demand priced rate available.

im talking about poco putting you on a demand meter based soley on service size. I dont think it happens.

 

[mrb]

Not a demand charge, but you gotta love this one. It has terminal where you pre-pay on the wall and lights out when your payment used up.

http://www.srpnet.com/payment/mpower/Default.aspx

just wait until power companies deploy their smart meters (which can be remotely turned on and off) and use them (by turning peoples power off) to shed load during peak usage to avoid having to buy high priced power from their competitors.

 

[JBurgess]

http://missionvalleypower.org/customer-services/rate-schedule/

RESIDENTIAL
Basic Charge: $7.50/month with or without meter

Energy Charge: $0.0497/kWh

Minimum Monthly Charge: $12.50/month

This classification is available to customers with single-phase electric service delivered through one meter to a single-family residence including domestic farm use. This class is limited to a maximum metered demand of 25 kW (kilowatts) per month and/or service panel less than 400 amps. Demand loads registering greater than 25 kW (kilowatts) two (2) months out of twelve (12) consecutive months, and/or 400 amp services or larger will be classified in a demand rate class. The term of contract for new services shall not be less than five (5) consecutive years.

 

[mrb]

http://missionvalleypower.org/customer-services/rate-schedule/

RESIDENTIAL
Basic Charge: $7.50/month with or without meter

Energy Charge: $0.0497/kWh

Minimum Monthly Charge: $12.50/month

This classification is available to customers with single-phase electric service delivered through one meter to a single-family residence including domestic farm use. This class is limited to a maximum metered demand of 25 kW (kilowatts) per month and/or service panel less than 400 amps. Demand loads registering greater than 25 kW (kilowatts) two (2) months out of twelve (12) consecutive months, and/or 400 amp services or larger will be classified in a demand rate class. The term of contract for new services shall not be less than five (5) consecutive years.

wow, ok -they do exist. thanks

 

[Terry Kennedy]

As the title states - I would like to swap out two 100 amp panels for two 200 amp panels in my two-family house to make wiring extra outlets easier, and also so that I can run a good amount of power to the detatched garage (the main reason).

I did the exact same thing several years ago. I replaced a pair of 16-position Federal Pacific 100A panels with 2 40-position Square D QO panels and a 20-position QO panel (so I could sub-meter the common areas). Since this was described as "electrician ****" on another board, I figured I'd post one of the images here for people to drool over.

Also - a friend mentioned that I might need bigger meters. Do they make 100 amp and 200 amp meters? And how can I tell which ones I have?

If you have rectangular meter bases like the ones in the following image, then they can probably handle 200A meters. When the utility company replaces meters (they have to do this every 10 years around here), they just put 200A ones in regardless of what was there - they don't bother keeping 60's and 100's in inventory any more. Look for something that says "CL100" or "CL200" on the meter face - that will tell you what is in there now. Note that that is just the meter - it doesn't imply anything about the actual service ampacity.

If you need to replace the feeders with larger ones and any part of the run is in conduit, you may need a larger conduit. In that case, you should probably just replace the meter bases as well. In some localities the utility supplies them, in others they spec what is needed and you have to buy them at an electrical supply house.

 

[checkthisout]

Yes you need bigger service entrance wire if you are upping the amperage.

Why would you upgrade your service just to make running extra outlets easier?

You can get 80 spaces out of a 40 space box depending on how much 220 you have. (40 spaces is huge).

And how does another box make running outlets easier?

 

[Terry Kennedy]

You can get 80 spaces out of a 40 space box depending on how much 220 you have. (40 spaces is huge).

How do you get around the 42 poles per panel restriction in the 2005 NEC (408.35)? This is changed in the 2008 NEC (which may not have been adopted in your jurisdiction yet), but most panelboards will have been designed to the 2005 or earlier code and will have interlocks to prevent installation of tandem breakers in some or all slots (depending on the number of full slots in the panel).