I'm in the process of remodeling my basement. I have an unused panel downstairs that only has 3 leads into it. I plan on installing a 100 amp sub in it's place. The original panel was 100 amp for a dryer and A/C that is no longer used. My question to the electrical geniuses that frequent this site... do I need to run a ground back to the main panel? (difficult in finished basement). Can I make the 3 existing wires 2 hots and a neutral and add the ground with a 5/8 rod driven outside? I do understand the separation of neutral and ground in a sub, but can the ground be separate from the main?
Gounding back to main panel with sub.
- Thread starter Rocket79
- Start date
Aceman
Well-known member
The only thing you can do with that existing cable is use it for a 120 volt only panel.
If you want 240v with a neutral, you're going to have to run another proper 4 wire cable instead.
If you want 240v with a neutral, you're going to have to run another proper 4 wire cable instead.
Aceman
Well-known member
You don't need to clarify, I already understand you have a 3 wire SE cable feed to an unused 240v panel. You need a 4 wire cable to do it properly.
Adding a ground rod does not take the place of a 4th wire.
I know it's not the answer you were looking for but there really is no other way around it.
wyliesdiesels
Well-known member
uggg
....*facepalm* First off, grounding electrodes and EGCs ARE 2 COMPLETELY DIFFERENT THINGS! People get this confused almost everyday and I explain this on here at least twice a week.
A ground rod DOES NOT provide a ground fault path for the breaker. Grounding electrodes are for grounding lightning ONLY. A ground rod will do NOTHING FOR U HERE!
While yes this is an old feed, anytime u change electrical it HAS to be brought up to current code. Old code allowed 3-wire feeds. Now 4-wire feeds are required! With one exception, code does NOT allow the ground wire to be separate from the circuit wires.
If u will be replacing the panel, your gonna have to either: A) run a green ground wire ONLY if the feeder cable is individual wires such as THHN and DOES NOT have an outer jacket or b) run an entirely new feeder with 4-wires.
Aceman understood your question perfectly.
And BTW, ground rods are only needed at the main service and detached buildings!
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Looks like I'll be doing a little sheetrock repair too. Thank you for the insight and help.
justsam
Well-known member
Clearly updating to a 4 wire is the way to go but it may depend on your use.
As stated, you do have the makings of a very stout 120 volt feed. Depending on what you want to do in your basement this may be just fine.
As stated, you do have the makings of a very stout 120 volt feed. Depending on what you want to do in your basement this may be just fine.
While the dryer is gas now, and 120v would be fine for now, if we ever need/have to run a electric dryer I would need to be at 240v on this panel.
Better build it right the first time.
Zeke
Well-known member
Electric dryers eat energy and cost money. If you do decide to get a 240v dryer you can run wire then. For now, you won't have that impetus. Only time I'd have an electric dryer is if the house was on a propane tank.
wyliesdiesels
Well-known member
Why is that? Theres dryers that will run on propane!
Beemer533
Well-known member
Probably because propane is so damned expensive compared to NG, that it wouldn't be worth it..