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-   -   Main Panel / Service Upgrades (http://www.diychatroom.com/f18/main-panel-service-upgrades-56574/)

gbe 11-04-2009 02:48 PM

Main Panel / Service Upgrades
 
I'm looking to add a few circuits to my home (built 1955) to go with a garage enclosure and a new auxilliary building, but the current panel is both full and looks to have a questionable work history. Additionally, there is no main breaker on the panel. For simplicity's sake, I believe a panel replacement would be the best solution both for this task and allowing for future expansion.

I am confident in my abilities to replace the panel (and what I'm not comfortable with, my father can almost certainly handle), but am unsure about a few things which may trip me up at inspection time. Any comments or advice on these would be much appreciated:

1. No ground circuit in the house. The wiring to most of the house (all except garage) is fabric-sheathed, 2 wire cable. I plan to use GFCI breakers on these circuits, so that while not grounded, the circuits will be protected. Will that suffice, or will I have to upgrade my wiring? As far as the ground circuit goes, I have a water pipe entering the house approximately 10' from the panel that I could ground to; alternately, I can easily drive a ground spike. This will give me a ground for any new circuits that I add.

2. Wire length. The current panel is smaller than any replacement panel will be, and routing the existing wires into place may be a problem unless I splice on some pigtails. Can this be done? If so, should it be in a dedicated junction box or can it be done in panel? Will my inspector yell at me?

3. Service upgrade. I believe (not sure) that I have 100amp service at present. What is involved in upgrading the service? I know I'll need a heftier cable from meter to panel, but will the mater also need upgrading? Is that my responsibility or the power company's?

Thanks much

Scuba_Dave 11-04-2009 03:03 PM

What size service do you have right now? 100a ? 200a ?
If 200a a sub-panel might be a good route
If 100a you might look into upgrading to a 200a
Best bet is to check w/local building Dept & see what they want in advance

You will need 2 ground rods driven outside & connected to the panel w/min #6 wire

You can make splices inside the panel, again run this by the Inspector
Some might disagree

If you don't have a main disconnect on the panel then you must have one outside
Check to see what the rating is & if other breakers are in that panel/disconnect

Upgrading may need a new service feed to your house
200a will need a new meter, usually you pay for that
In some cases you may need to pay for the service feed upgrade
Call your POCO to find out & if you can upgrade

I'd upgrade to 3 wire NMB wherever possible

Any pics if the current panel ?

gbe 11-04-2009 03:29 PM

Thanks for the quick replay, Scuba_Dave.

No pics with me at present, but I'll take a couple this evening and post them.

I'm not sure what the service size is presently. If I had to guess I'd say 100a. I wouldn't mind an upgrade to 200a - in fact that'd be for the best as I'd like to provide a 60a circuit to the new building.

So I'll have to have a main disconnect installed regardless? That shouldn't be hard to do.

Wiring upgrades are going to be difficult in this house, but I'll upgrade what needs upgrading to make it safe. Is it going to be a requirement to do so to replace the panel?

Scuba_Dave 11-04-2009 04:44 PM

Usually you do not have to upgrade wiring & other items when replacing a panel
But local codes can be different & local Inspector may have his own opinion

220/221 11-04-2009 07:14 PM

Quote:

I plan to use GFCI breakers on these circuits, so that while not grounded, the circuits will be protected. Will that suffice, or will I have to upgrade my wiring?
That is a good plan if there are no 3 wire home runs (black, red, white wire in one cable)

Quote:

The current panel is smaller than any replacement panel will be, and routing the existing wires into place may be a problem unless I splice on some pigtails. Can this be done? If so, should it be in a dedicated junction box or can it be done in panel?
You can splice in the panel but try not to. Relocating the new panel up a bit will give you more length on your existing cables if the enter the top of he box.


Quote:

What is involved in upgrading the service?
Grounding and bonding need to be upgraded along with the meter socket, service conductors. This will be mostly your responsibility and methods vary in different jurisdictions.

Typically, two 8' ground rods, 6' apart with #6 wire for grounding.

#4 wire to metallic piping systems for bonding.

fltdek 11-04-2009 07:34 PM

Someone else correct me if I am wrong, but if you have older wiring w/out ground, as typical in alot of older homes, putting a GFCI breaker in your panel will not provide ground fault protection to your circuit, as there is no ground from the outlet back to the panel..... you would have to upgrade the wiring.

fltdek 11-04-2009 08:19 PM

Wow, can you explain why it would then. .....I asked an electrician, he said it would not protect the circuit. Please explain.

fltdek 11-04-2009 08:30 PM

Wrong!
 
My mistake! Amazing what you learn in these forums! I am not a real electrician, I just play one on TV. So, after a little digging, this is what I found:

According to the NEC, it is allowable to install GFI's in ungrounded situations. This makes sense, since the GFI is not dependent of the ground to function. Remember, it does not measure shorts to the ground, it measures the current difference between the hot and neutral wires. A sudden difference, indicating that there is another path for the electricity to flow through... you, for example, causes the GFI to open the circuit and save you from permanently curly hair.

Of course, most safety-conscious electricians prefer not to install a grounded-type "three prong" outlet in an ungrounded situation. Think about it... once the outlet is installed, there is no way for anyone to know if the outlet is really grounded or not without testing it. Thus, there is a hidden shock hazard should an appliance or tool that needs grounding... has three-prong plug... is plugged into this outlet.

However, the NEC allows GFI's to be installed in ungrounded situations PROVIDED THAT the outlet is labelled "ungrounded". Though not "officially" approved in the NEC, the grounding hole in the GFI can be permanently defeated by using an epoxy or other adhesive to seal the hole.
Though a GFI will activate if a grounded appliance develops an electrical short circuit to ground... such as when YOU touch a metal saw and become the path to ground... you will experience a momentary electrical shock. This could be a minor tingle or could be more catastrophic, especially if you are on a ladder or roof. This excerpt is from an OSHA (Occupational Safety and Health Administration) article on wiring in nursing homes and the dangers to employees working with ungrounded outlets...


THANKS BUSMAN!

gbe 11-04-2009 08:44 PM

pics of current panel / replies to replies
 
As requested, here are some pics of the current panel. Apologies for the poor quality in picture 2, but my photography skills aren't great.

http://lh5.ggpht.com/_PeQdQCCohZY/Sv...8/DSC05082.JPG
The cutout has been snipped at the top

http://lh5.ggpht.com/_PeQdQCCohZY/Sv...8/DSC05083.JPG
http://lh4.ggpht.com/_PeQdQCCohZY/Sv...8/DSC05084.JPG
The top left dual 50a breaker shuts off the 10 110v circuits below it, as well as the stove and dryer circuits, which are wired into the lugs that the 50a breaker connects to. The dual 30a breakers on the top right control the A/C outdoor unit and an older, unused window unit outlet. Its not readily apparant in the picture, but the A/C's wiring isn't 3-conductor wire, its 2-conductor+ground. Uses the black and white as hot and the ground wire as neutral. Seems unsafe/unwise/lazy to me, but I'm not an expert at this.

http://lh4.ggpht.com/_PeQdQCCohZY/Sv...8/DSC05085.JPG
http://lh4.ggpht.com/_PeQdQCCohZY/Sv...8/DSC05086.JPG

To answer other questions/comment on replies thus far:

Quote:

220/221 - That is a good plan if there are no 3 wire home runs (black, red, white wire in one cable)
There are, I believe, 3 of these - the stove, A/C, and dryer. Two are easily upgradable if need be. The third can probably be done with minimal fuss. Can I simply GFCI the ungrounded 2-wire circuits and upgrade the wiring on the ungrounded 3-wire other guys?

Quote:

220/221 - You can splice in the panel but try not to. Relocating the new panel up a bit will give you more length on your existing cables if the enter the top of he box.
That'll probably be a doable option. The only circuits that presently enter through the bottom are circuits that I have easy access to, so replacement would be simple.

Quote:

busman - Someone else correct me if I am wrong, but if you have older wiring w/out ground, as typical in alot of older homes, putting a GFCI breaker in your panel will not provide ground fault protection to your circuit, as there is no ground from the outlet back to the panel..... you would have to upgrade the wiring.
Just to be sure I'M up on how GFCI works - the breaker/outlet monitors the hot and neutral wires to make sure the current is equal between them. IF there is ever a difference (fault), the breaker/outlet trips and kills power to the circuit downstream of the outlet? So while a GFCI won't ground a circuit, it'll protect the circuit in case of fault.

Jim Port 11-04-2009 08:54 PM

Quote:

Originally Posted by gbe (Post 349158)
, I can easily drive a ground spike. This will give me a ground for any new circuits that I add.

The grounding rods have nothing to do with providing a ground for the new circuits. Ground rods are for lightning and other high voltage events.

The ground of circuits would come from an equipment grounding conductor run with the new circuits.

gbe 11-06-2009 10:50 AM

sorry to bump, just trying to figure out everything in my last post before i get moving

220/221 11-06-2009 06:03 PM

Quote:

Can I simply GFCI the ungrounded 2-wire circuits and upgrade the wiring on the ungrounded 3-wire other guys?

Use GFCI breakers for the 120 volt 2 wire circuits. Both the black and white wires terminate on the breaker.

You can leave the 240 volt stuff as is unless you want to upgrade. In the olden days the 240 appliances used the same wire for the neutral and ground. It's still legal to use existing circuits like this but it's not a bad idea to replace them. In a typical panel change I just leave it the way it was. If there is more work going on like a full kitchen remodel with new appliances, I will try and sell them new 240V circuits.

Quote:

Just to be sure I'M up on how GFCI works - the breaker/outlet monitors the hot and neutral wires to make sure the current is equal between them. IF there is ever a difference (fault), the breaker/outlet trips and kills power to the circuit downstream of the outlet? So while a GFCI won't ground a circuit, it'll protect the circuit in case of fault.
You got it.

gbe 11-06-2009 11:20 PM

Quote:

Originally Posted by 220/221 (Post 349957)
Use GFCI breakers for the 120 volt 2 wire circuits. Both the black and white wires terminate on the breaker.

You can leave the 240 volt stuff as is unless you want to upgrade. In the olden days the 240 appliances used the same wire for the neutral and ground. It's still legal to use existing circuits like this but it's not a bad idea to replace them. In a typical panel change I just leave it the way it was. If there is more work going on like a full kitchen remodel with new appliances, I will try and sell them new 240V circuits.

Thanks for your help. From looking around a bit I can see exactly what you mean re: installing the GFCI breakers (black+white terminate on the breaker, breaker's pigtail connects to neutral bus bar).

Good news re: leaving the existing 240V circuits as is. It wouldn't be too hard to replace them, but if I can leave as is for now and come back to it later thats a good thing to know.


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