Panel Mess


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Old 07-11-06, 10:04 AM
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Panel Mess

I'm remodeling a 1954 house that has a 100 amp main.
It's a mess, but it can be fixed. Basically, the main is located on an exterior wall with a 100 amp disconnect and there are code compliant circuits for a bedroom/bath addition that was done about 8 years ago - included a 50 amp spa circuit, a 30 amp WH circuit and 2-20 amp circuits (1 for bath and 1 for bedroom). All of the circuits for the addition were wired with correct size NM cable. Bdrm is not AFCI protected, but it's not being touched.

The problems occur in the older portions of the house which includes a Kitchen, Living/Dining Rm, Bedroom & Bath.

First, all of this is wired with older #14 NM w/o ground, and the kitchen needs additional circuits. The breakers are all 20 amp, so even those circuits that only need to be 15 amp need to have the breakers changed. Some of the conduit into the house is metal and some is plastic. These conduits run along the outside wall and enter the house a several different locations - very unsightly - but all on one wall. There is adequate attic space with easy access to the area directly above the main service.

I will be totally remodeling the old bath and Kitchen plus I'll add a Utility Room for the Stacked Washer/Dryer that was in the old Kitchen. The Living/Dining Room and the Bedroom are not going to be changed except that I'll add GFCI protection and replace the wall fixtures with 15 amp 3-prong outlets with the "no equipment ground" note.

My plan is to provide a new sub-panel in the dining room with circuits to serve the kitchen, a bath and the laundry. This is a central location which would minimize the amount of #12 and #14 NM that I would need to run for the new 15 and 20 amp circuits for these areas. I will need the normal kitchen circuits (gas range) and the laundry has a gas dryer.

Bath.......... 20 amp circuit
Kitchen...... 2 20 amp small appliance circuits
................ 20 amp circuit for microwave/hood
................ 15 amp circuit for DW & Disposal
Laundry..... 20 amp circuit for Washer/Dryer (gas dryer)
Lighting..... 15 amp circuit

So, I'm planning on a 40 amp sup-panel with main disconnect using 8-3 w ground from the main panel. I would abandon and remove the old circuits that served these things previously and install a new conduit from the main panel up to the attic to run the cable for the new sub-panel, and then remove extra breakers, etc. Naturally, I will use GFCI as required by code, etc.

If I use this sub-panel approach, what do I need to do about the open spaces left by the breakers that have been removed from the main panel? Obviously, some of those will be filled by the double 40 amp for the sub and I can replace some thin line breakers with full width, but there will still be some openings.

If I use this approach, there will still be several exterior conduits, but I expect to eliminate at least 4 of them. I will also need to cap the open holes left by the remove conduits (both at the panel and where they enter the house).

Any other comments would be welcome.

Thanks, Joe
 
  #2  
Old 07-11-06, 10:14 AM
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Make your dishwasher/disposal circuit a 20 amp circuit. Better yet, make it a 20 amp multi-wire circuit.

The 20 amp circuit for the washer and dryer cannot power a light in that room (or anywhere).

Add a 20 amp circuit to the kitchen for the refrigerator.

Make the sub panel larger than 40 amp.

The holes in the main panel need to be filled. For the breaker holes either leave unused breakers installed or use filler panels. For the conduit holes use snap in covers.
 
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Old 07-11-06, 10:26 AM
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Originally Posted by racraft
Make your dishwasher/disposal circuit a 20 amp circuit. Better yet, make it a 20 amp multi-wire circuit.
So I should use 12-3 w/g ? One hot for DW and one for Disp?

Originally Posted by racraft
Add a 20 amp circuit to the kitchen for the refrigerator.
Really? I'm only going to have a 30" wide 21 cu.ft. Refrig/Freezer. Can't this just be on one of the small appliance cirduits? But it won't be a big deal to provide a separate circuit.

Originally Posted by racraft
Make the sub panel larger than 40 amp.
I calculate a demand load of only about 2000 watts - do I really need a bigger sub-panel? If I go to a 50 or 60 amp, what size feeder would I need?

Originally Posted by racraft
The holes in the main panel need to be filled. For the breaker holes either leave unused breakers installed or use filler panels. For the conduit holes use snap in covers.
OK, so I can just leave unconnected breakers in the main (marked "spare") ?
 
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Old 07-11-06, 10:59 AM
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Pretty much yes to all of your questions.

Yes, you may use one of the small appliance circuits to power your refrigerator but it is really better to have it on a separate circuit. You don't need, nor is it preferred to have the refrigerator on a GFCI.

The sub-panel will most likely have a rating of no less than 60 amperes although that does NOT mean that you have to wire it with a 60 ampere feeder. Select a sub-panel with enough spaces to accomodate all your circuit breakers and still have one or two spaces in case you may sometime in the future wish to add more circuits. A 60 ampere sub fed from the service panel with #6 THHN/THWN individual conductors housed in conduit. You may use a 40 ampere circuit breaker in the service panel if you so desire but the extra capacity will be there if ever needed.

You may not leave any openings in the panel(s) that allow entrance to any live parts. Simply retaining the existing breakers and labeling them as spares is a good idea.

As for the holes in the service panel where you will be removing conduit...since this panel is outside I would use the hole covers that have a screw in them and a bar across the hole inside of the enclosure instead of snap-in plugs. Use a bit of siliconized acrylic caulk under the outside piece to make the plug weather proof. Do not use 100% silicone caulk as you will not be able to paint it.
 
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Old 07-14-06, 08:11 AM
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OK, I purchased a Square-D 125 amp indoor load center to use as the sub-panel.

My plan is:

Mount the sub-panel and feed it with a 60 amp double breaker at the service panel using #6 THHN/THWN individual wires in conduit.

Can I use 6-3 w/g cable (conduit from main service to attic) ?
I only need about 30-35 feet of wire to go from the service panel to this sub-panel. It would be pretty easy to run the sheathed cable thru a short section of conduit.

Should I bond the Neutral in the sub-panel to the box or should the ground and neutral remain separate?

Do I need to provide a disconnect in this sub-panel or just rely on the 60 amp double breaker at the service panel?
 
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Old 07-14-06, 09:25 AM
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Joe,

Joe, I recommend staying with one type of cable/wire to feed he panel. Every junction box is a potential failure point. Why introduce one if it not needed? A short section of NM can be put through conduit for protection.

I cannot verify the wire size, but I believe you will need larger cable for 60 amps.

At a sub panel in the same building as the main panel, the neutral and ground MUST be separated.

Yes, you need a disconnect in the sub panel.
 
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Old 07-14-06, 09:46 AM
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I wasn't suggesting using two different wire types or any junction boxes. I'm saying I would just prefer to use Romex (short length of conduit) instead of separate wires that would need to be enclosed in conduit for the entire distance between panels.

Why is a disconnect needed in the sub-panel if it's connected to a breaker in the main service panel? Is this a code requirement? I've seen other sub-panels (30-60 amp) that are just connected to the BUSS. This particular panel is fabricated to be wired either way. When would it be appropriate to use direct wiring vs disconnect.
 
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Old 07-14-06, 10:00 AM
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six breakers or less.
 
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Old 07-14-06, 10:05 AM
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Thanks - now I understand.
 
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Old 07-15-06, 12:27 AM
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Originally Posted by racraft
Joe,

Yes, you need a disconnect in the sub panel.

six breakers or less.

Each building or structure is required to have a disconnecting means (Main Disconnect) at the point of entry of the conductors serving it. Generally, this disconnecting means cannot consist of more than six switches or breakers. This is to disconnect power from the building, it does not apply to each panelboard in that building.

Panelboards are required to have an overcurrent protection device (OCPD) that does not exceed the rating of the panelboard. The breaker protecting the feeder to the panel can meet this requirement. This is not the same requirement as the main disconnect requirement.

If the main panel is at, or very near, the point where the conductors serving the building enter the building, then a main breaker can serve as both the main disconnect and the OCPD for that panel. And, sub panels in the same building can have up to 42 breakers (the max for lighting and appliance panelboards) without a main breaker as long as the sub panelís feeder is protected by an OCPD that does not exceed the sub panelís rating.
 
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Old 07-16-06, 07:55 AM
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Thanks Juhl, that makes sense! It also coincides with what the expert at HD told me.

I will install a double 60 amp breaker in the main panel to protect the #6 feeders that will serve the sub-panel. Since the panel is rated for up to 125 amps, the critical element to protect will be the feeders.

I could use larger feeders and increase the breaker size, but this installation will never need anything more than 60 amps.
 
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Old 07-16-06, 07:57 AM
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Originally Posted by Joe.Carrick
.......the expert at HD.........
There are many, MANY folks who would consider this an oxymoron.
 
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Old 07-16-06, 09:11 AM
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.......the expert at HD.........
There are many, MANY folks who would consider this an oxymoron.
Gee... how did I know you weren't going to let that one get by, Speedy?
 
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Old 07-16-06, 09:58 AM
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Just doin' my job.
 
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Old 07-17-06, 07:05 AM
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Originally Posted by Speedy Petey
There are many, MANY folks who would consider this an oxymoron.
Right, including me in most cases.

This time it was a semi-retired electrician.

Occasionally you find someone at HD who actually does know what they're talking about.
 
 

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