# Remodel - Moving from 200 amp service to 320 amps



## chris75 (Aug 25, 2007)

stevedar said:


> We are doing a remodel and I've pulled my own permits and have "some friends" helping me who are licensed electricians. We are adding a garage onto the side where the old garage was located, then expanding the floorspace to include the garage - a fairly typical remodel I would think.



Who did the load calculation that came up with a 320 amp service for converting a garage to finished space?


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## stevedar (May 22, 2008)

The Power Company made the recommendation to bump to 320 amp service. I was told that with a furnace, heat pump, sauna, & hot tub I would be right on the edge of what could be provided with a 200 amp service. 

Part of what seemed appealing was the transition plan and one thing I saw as being problematic was that we had nearly used up all the breakers in the existing box and there were going to dozens of new circuits to be added. We're moving the kitchen where the bathroom used to be and putting the bathroom where the door used to be and on and on. Lots of changes which will affect wiring.


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## J. V. (Jun 1, 2007)

If you need more breaker spaces you can add a sub panel. 

I would upgrade to a 400 amp service not a 320 amp service. 400 amp service panels are common. You might need to factory order a 320 amp panel. Personally I have never seen one.

I would use a 400 amp meter / load center combo unit. Keep in mind that if you use a meter/load center service panel, any additional panels will be sub panels and you can use lug panels instead of main breaker panels, provided the panels are under one roof. (attached). Make sure the meter / load center service panel has lug capability for 2 sub panels. Or you can install a gutter and splice the conductors for the sub panel feeders.

2 -200 amp subs will give you 80 breaker slots and should cover most any residential application.


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## HouseHelper (Mar 20, 2007)

First, I would do, or have one of your "friend electricians" do a load calculation to make sure you really need a 320/400A service. You may be able to stay with the 200A and just add additional subpanels.

If you do go with the 320/400A upgrade, install two 200A disconnects outside adjacent to the meter. You could then place the distribution panels (wired as subpanels) where ever you need to.


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## BigJimmy (Jun 30, 2006)

320A? Holy crap, Lois!

Buy a co-gen unit and get fat selling electricity to your neighbors.


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## chris75 (Aug 25, 2007)

stevedar said:


> The Power Company made the recommendation to bump to 320 amp service.



Did they do a load calculation? Gezz... I guarantee your wasting your money.


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## stevedar (May 22, 2008)

Obviously, my home was not wired properly in the first place. Here are some examples:

There is one GFCI circuit for 2 bathrooms and 2 outside outlets. We are constantly tripping the GFCI circuit (15 amps).

There were only 3 outlets in the garage aside from the one dedicated to the dryer. We had plugged in a flourescent light (4 foot), an attic light (2 x 4' flourescent), a small TV, a washing machine, a freezer, a spare refrigerator, a radial arm saw, and a gizmo that boosted the analog cable signal. The radial arm saw would take down everything...

I realize it's not possible to do a load caculation without having the precise specifications, but take this into consideration. We are not on a gas line and natural gas is not likely to come soon, nor do I care since electricity is STILL cheaper than most energy sources here in WA state. Consider this list of electrical components and see if it doesn't start to push the 200 amp service:

50 gallon HW heater
Heat Pump Unit (Exterior fan)
Furnace
Washer 
Freezer
Refrigerator (2)
Dryer
Jetted tub with heater
Outdoor Spa
Sauna (traditional rock heater versus the new style radiants or whatever they're called)
Double Ovens
Large Microwave
Cooktop
Range Hood
Dishwasher
Computers (3 rbunning 24 x 7 [w/o monitors])
Stereo
Plasma TV
LCD TV 
Lighting and outlets for 2500 sq ft house
Whole House Fan 
Block Heater for 1986 Ford P/U (only during winter months)
Shed lighting
Yard lighting
Deck lighting
Driveway lighting
Garbage Disposal

Other tools that may be used infrequently:

Radial Arm Saw
Grinder
Air Compressor

What if having 320amp service would help me sleep better at night? 

I'll let you know what I figure out once we start on it tomorrow.


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## Speedy Petey (Feb 1, 2004)

J. V. said:


> I would upgrade to a 400 amp service not a 320 amp service. 400 amp service panels are common. You might need to factory order a 320 amp panel. Personally I have never seen one.
> 
> I would use a 400 amp meter / load center combo unit. Keep in mind that if you use a meter/load center service panel, any additional panels will be sub panels and you can use lug panels instead of main breaker panels, provided the panels are under one roof. (attached). Make sure the meter / load center service panel has lug capability for 2 sub panels. Or you can install a gutter and splice the conductors for the sub panel feeders.
> 
> 2 -200 amp subs will give you 80 breaker slots and should cover most any residential application.


That sounds like a LOT of work for the SAME end result.

You would really install a 400A panel, and two 200A sub-panels?????
I have never seen a real 400A service in a residence around here. Everyone uses 320A plug-in meter bases and *two 200A main breaker panels*. Clean and simple. We do NOT use one 320A panel.
400A panels are certainly common, for commercial applications, AND the are EXPENSIVE. 

A 320A service is 320A continuous and 400 max.
A 320A service is the SAME thing as a 400A service, only you use WAY less material and the job takes MUCH Less time to install. The only difference is the service entrance wire size, which is base on the calculated load.

I personally think a "real" 400A service in a home is pointless and wasteful.
This is just my opinion. :thumbsup:


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## chris75 (Aug 25, 2007)

stevedar said:


> Obviously, my home was not wired properly in the first place. Here are some examples:
> 
> There is one GFCI circuit for 2 bathrooms and 2 outside outlets. We are constantly tripping the GFCI circuit (15 amps).


Depends on when your house was wired. 



stevedar said:


> There were only 3 outlets in the garage aside from the one dedicated to the dryer. We had plugged in a flourescent light (4 foot), an attic light (2 x 4' flourescent), a small TV, a washing machine, a freezer, a spare refrigerator, a radial arm saw, and a gizmo that boosted the analog cable signal. The radial arm saw would take down everything...


Code only requires 1 receptacle, what you have is a bad design. 



It's your money if you want the 320 service, IMO, not required and just plain overkill.


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## Speedy Petey (Feb 1, 2004)

stevedar said:


> Obviously, my home was not wired properly in the first place. Here are some examples:
> 
> There is one GFCI circuit for 2 bathrooms and 2 outside outlets. We are constantly tripping the GFCI circuit (15 amps).


I agree. This was VERY common in the 70's. My own house is wired this way. I put GFI devices in all the places so tripping a GFI breaker is no longer a hassle.






stevedar said:


> There were only 3 outlets in the garage aside from the one dedicated to the dryer. We had plugged in a flourescent light (4 foot), an attic light (2 x 4' flourescent), a small TV, a washing machine, a freezer, a spare refrigerator, a radial arm saw, and a gizmo that boosted the analog cable signal. The radial arm saw would take down everything...


Are you saying you find it odd that ALL that stuff is tripping a breaker?????
That is simply WAY too much for a 15 OR 20 a circuit.


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## wire_twister (Feb 19, 2008)

Petey, Your AHJ allows you to size those service entrance conductors based on calculated load? Around here a 320 amp meter base better have 500mcm copper for service entrance conductors or it will not pass. I guess they figure with 2 200 amp panels you could somehow draw 400 amps and they want the SE conductors to be rated at that. I know 500 mcm is rated at 380a per 310.16 but it is accepted for 400 amp service here.


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## J. V. (Jun 1, 2007)

Speedy Petey said:


> That sounds like a LOT of work for the SAME end result.
> 
> You would really install a 400A panel, and two 200A sub-panels?????
> I have never seen a real 400A service in a residence around here. Everyone uses 320A plug-in meter bases and *two 200A main breaker panels*. Clean and simple. We do NOT use one 320A panel.
> ...


I agree that a 400 amp service for residential is not the norm, when sub panels can be added as needed.


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## stevedar (May 22, 2008)

I appreciate everyone's response and suggestions. I must admit that I am electrically challenged, however, my brother and my son are very comfortable with the concepts and have a much deeper understanding of the principles that lie behind how things work electrically. This is of course a troubling thing to find that a sibling *and *a child can do something better than you can, so you try to better yourself, day by day, and one day hope to zing one in on them.

The house was built in 1985 as a simple 24' x 60' rambler. Not exactly "peak times". For years the house was heated with a wood stove and a "toaster" in every room - which in case you've never seen them they are oblong shaped with a noisy little fan that pulls air across hot coils. I guess it was supposed to look like a modern convenience - separate thermostats in every room! But in reality it was just cheaper to get a house built that way. 

At the time though we felt very lucky to have it because we didn't have much money and they had offered it on a 3-2-1 buydown which worked well for us given that we had steady jobs and some likelihood of having our income rise around 3 to 5% per year to cover the 1% increase in interest rates. I guess, looking back, times were probably like now, bad.

The house was then remodeled sometime in the early nineties. We made all the classical mistakes - tried to design it ourselves, hired a bad GC who hired _really bad_ subs, and came in over slightly over budget. At less than .45 a square foot, including kitchen, new bath with sauna and jacuzzi tub, it didn't seem like such a bad deal although you know that corners were cut and there was a lot of frustration. And more bad wiring...

Back on point, if so many people tell me that it's overkill, then I will look into cancelling it and see what I will pay just to have them move me underground. We are landlocked and so our power is run down a line shared with only 2 other houses so if a tree drops on my line during a storm I am literally guaranteed to be the last one they get to, so going underground just seemed to be worth it especially since I would be having to trench for Verizon & Comcast. 

I am of Welsh and Scotch heritage, so I doubt I would have paid too much extra for pulling the 320 amps, I don't think? But maybe I did - I'll check.

So here come the stupid questions...

1. Doesn't it take a bigger wire to the house to get 320 amp service? It must since it calls for bigger conduit. Part of my reasoning was what may come in the future? Suppose I want to charge up my scooter so I can ride to work? I may need to be charging a car or running a centrifuge so that I can get to work every day. What if I have some repressed desire to take up welding?

2. Remodels are tough to do - can anyone suggest what to do to get through the transition from overhead to underground *and* keep power to the house during transition *and *allow me to reuse the old circuits? Copper is so expensive these days as are labor costs. I can easily handle a 24 hour period without power - possibly longer.


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## Speedy Petey (Feb 1, 2004)

wire_twister said:


> Petey, Your AHJ allows you to size those service entrance conductors based on calculated load? Around here a 320 amp meter base better have 500mcm copper for service entrance conductors or it will not pass. I guess they figure with 2 200 amp panels you could somehow draw 400 amps and they want the SE conductors to be rated at that. I know 500 mcm is rated at 380a per 310.16 but it is accepted for 400 amp service here.


Well first off we do *not* use 310.16 for residential services. We use 310.15(B)(6). For a 320/400A service we would use 350CU or 500AL.

YES, a service is sized according to the calculated load. Even an overkill guess is accepted. By this I mean going bigger is never a problem. 

If your guys require 500CU for a 320/400A service, how can they justify letting you use a 320A meter base???? This is silly.

I am surprised you guys are surprised at this. I thought a 320A service was extremely common all over. :huh:


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## chris75 (Aug 25, 2007)

Speedy Petey said:


> .
> 
> I am surprised you guys are surprised at this. I thought a 320A service was extremely common all over. :huh:


Me too, I use them quite often, and they are usually way overkill, but hey, I'm in it for the money.


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## Speedy Petey (Feb 1, 2004)

chris75 said:


> Me too, I use them quite often, and they are usually way overkill, but hey, I'm in it for the money.


Damn straight. :thumbsup:


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## jbfan (Jul 1, 2004)

I have only installed 3 400 amp services. I get the meter bases from the POCO, and feed 2 200 amp disco, then feed 2 200 amp MLO panels. All 3 have had underground service, so wire size was not anything I needed to worry about!

As a side note, I do not wire many new houses. Just not my cup of tea.
All of these were for family or friends.


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## ssousa (Nov 29, 2009)

*320A is 400*

Though every one calls the meter base 400A, it is not truely a 400A base but a 320A base as you are only allowed 80% of rated load by code. So while they are calling it 400A service it is not.


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## frenchelectrican (Apr 12, 2006)

ssousa said:


> Though every one calls the meter base 400A, it is not truely a 400A base but a 320A base as you are only allowed 80% of rated load by code. So while they are calling it 400A service it is not.


 
I just want to clear up that fact there are few 320/400 amp meter socket and they do come in few diffrent verison depending on the location and useage.

Typically in resdentail it pretty common to use the 320A push on meter socket 
However some POCO required that have to be run in CT { current transfomer } 
Farm are mantory 400 amp either CT or bolt on meter socket depending on the set up

Commercal automatic use full 400 amp meter socket and it will come either bolt on or CT regaurdless of system voltage and phases.

Merci,Marc


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