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stevedar 05-22-2008 03:59 AM

Remodel - Moving from 200 amp service to 320 amps
 
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.

Since we had to move the service feed anyway we decided to go underground. And, if there is still an extra $5K left in the budget we may add a hot tub to the deck and even if we don't have the $$$ yet, we want to wire for getting one in the future. We are all electric (no gas lines yet) and have a sauna and a heat pump and so it seems to make sense that we should upgrade to 320amp service. Needless to say, the power company is ecstatic about the prospects and has been very helpful.

The first thing I learned is that I need 2 - 200 amp service panels, so I went out and bought 2 new Cutler Hammer copper bus service panels. To continue living in the house the idea was to do a "temporary drop" from one of the new service panels over to the old service panel. There are quite a few things that are going to change wiring-wise inside the house, but many of the circuits that we have will stay "hot" even after the rework is completed.

The electrician I have is advocating that I then remove the wires one by one from the old service panel and tie them into one of the new service panels by installing what he calls a "J box" (just a junction box I guess?) in the attic and then adding the extra 25' of copper over to one of the new service panels.

However, after discussing this with a few other people who want to help and are also well qualified electricians, they are saying I don't really need to do that. The "temporary drop" can become permanent once the new garage is dried in. Just run that big hurking wire all the way over directly from the meter box, leave the old panel there (or put in one of the new Cutler Hammer boxes for consistency?) and that's that - you're done.

Any thoughts? If I go with the second electrician's suggestion, I would probably still need to turn the panel around so that both were facing the garage. Are there going to be regulations and codes about having 2 service panels a few feet apart? It appears to me that the house will now have 2 places to go to shut off the main breaker and they may not like that they will be 20' apart. If I go with the original electrician's suggestion, I will have 2 new panels in one place and even if I chose the other method I probably would end up fussing with the old service panel to flip it around to face the garage.

chris75 05-22-2008 06:49 AM

Quote:

Originally Posted by stevedar (Post 124971)
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?

stevedar 05-22-2008 09:59 AM

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.

J. V. 05-22-2008 10:56 AM

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.

HouseHelper 05-22-2008 10:57 AM

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.

BigJimmy 05-22-2008 01:31 PM

320A? Holy crap, Lois!

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

chris75 05-22-2008 05:11 PM

Quote:

Originally Posted by stevedar (Post 125006)
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.

stevedar 05-24-2008 01:28 AM

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.

Speedy Petey 05-24-2008 07:36 AM

Quote:

Originally Posted by J. V. (Post 125025)
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:

chris75 05-24-2008 08:37 AM

Quote:

Originally Posted by stevedar (Post 125468)
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.

Quote:

Originally Posted by stevedar (Post 125468)
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.

Speedy Petey 05-24-2008 09:26 AM

Quote:

Originally Posted by stevedar (Post 125468)
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.




Quote:

Originally Posted by stevedar (Post 125468)
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.

wire_twister 05-24-2008 10:46 AM

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.

J. V. 05-24-2008 12:34 PM

Quote:

Originally Posted by Speedy Petey (Post 125482)
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.

Speedy,


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

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

stevedar 05-24-2008 03:06 PM

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.

Speedy Petey 05-24-2008 05:43 PM

Quote:

Originally Posted by wire_twister (Post 125501)
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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