3 wire uninsulated SE cable for Subpanel

[euclid43]

I recently bid a subpanel installation in basement. Homeowner told me that other bidding EC's were using the existing dryer branch circuit for the subpanel.

Wondering how I can make this work....
1. Do I run EGC to the main, along side of SEU?
2. Can I bond to cold water pipe located 2 feet away?
3. As long as the only load is 120 (20 amp), can I leave as is and bond the neutral/ground?

Point my waywardness in the right direction, please.

I pointed this out to the homeowner: (1) She said it would be ok to get permitted, but rescinded any additional costs. (2)she refused to incurr any additional costs from bid amount.

I wanted her to show me where other EC's included 4 wire replacement in the competitive bid.

 

[Dennis Alwon]

IMO, you cannot add the wire on the outside--art. 300.3(B). Also if this is seu cable then you wouldn't be adding an egc you would be adding a grounding conductor. I would walk from that job unless she was willing to pay for the wire to be replaced. You probably should have had that in your bid.

 

[M4gery]

Can't you just use the cable to feed the panel with 120V and jump out the other leg so all spaces are hot?


This sounds like the type of customer you want to avoid, but her money is still green :happyyes:

 

[Dennis Alwon]

Can't you just use the cable to feed the panel with 120V and jump out the other leg so all spaces are hot?

What good would that do. You could not get two 20 amp circuits with that setup. I guess you could get 2- 15 amp circuits. Remember it's a dryer circuit.

 

[M4gery]

What good would that do. You could not get two 20 amp circuits with that setup. I guess you could get 2- 15 amp circuits. Remember it's a dryer circuit.

We don't know what the load will be on the subpanel, how do you know how many circuits and of what size he will be limited to?

As for what good it will do, it will allow him to compliantly install a subpanel in the fashion that the customer specifies.

 

[Dennis Alwon]

We don't know what the load will be on the subpanel, how do you know how many circuits and of what size he will be limited to?

As for what good it will do, it will allow him to compliantly install a subpanel in the fashion that the customer specifies.

You are correct that is why I stated you can only get "X" number of circuits. If all he needs is 2 - 15 amp circuits good-- obviously it would depend on the load. I would still run a new wire rather than make it a 120V panel. IMO, a 120V panel is the answer if there is no other alternative.

 

[M4gery]

You are correct that is why I stated you can only get "X" number of circuits. If all he needs is 2 - 15 amp circuits good-- obviously it would depend on the load. I would still run a new wire rather than make it a 120V panel. IMO, a 120V panel is the answer if there is no other alternative.

I think I am probably missing something here which is why I continue to post about it (it's the only way I learn). Earlier you said "You could not get two 20 amp circuits with that setup." I am curious why you can't get (2) 20A circuits or even (4) of them?

 

[Dennis Alwon]

I think I am probably missing something here which is why I continue to post about it (it's the only way I learn). Earlier you said "You could not get two 20 amp circuits with that setup." I am curious why you can't get (2) 20A circuits or even (4) of them?

Well if the load on 2 twenty amp circuits were 20 amps and they were on the same phase then the neutral would carry 40 amps-- the dryer is a #10 I presume-- 30 amps.

 

[infinity]

Well if the load on 2 twenty amp circuits were 20 amps and they were on the same phase then the neutral would carry 40 amps-- the dryer is a #10 I presume-- 30 amps.

Wouldn't that also give you 40 amps on the ungrounded conductor? That would surely trip the 30 amp OCPD.

 

[Dennis Alwon]

Wouldn't that also give you 40 amps on the ungrounded conductor? That would surely trip the 30 amp OCPD.

Yes it would. It all depends on the load. I guess I was thinking neutral overload but,, of course, t would overload the feeder also. And sure you could have 6 sp breakers in there if the load wasn't very much but I was assuming it would be loaded somewhat. My point is with a #10 on one phase you don't get much from it. I would rewire the feeder as it appears it is possible so........

 

[M4gery]

Well if the load on 2 twenty amp circuits were 20 amps and they were on the same phase then the neutral would carry 40 amps-- the dryer is a #10 I presume-- 30 amps.

I see, but that is provided that you had (2) fully loaded 20A circuits. In reality the panel would be full of 15A and 20A breakers yet the load would probably be well under 30A. This is just an assumption, but it may very well be true. As I'm sure you know, in many houses when you take away the kitchen, bathroom, and AC or large appliances- the entire remainder of the house could very well use less than 30A.

If it did overload the 30A feeder, then it would be easy to say to the lady, "This is exactly what you wanted to do, even against my warning. The only correction is to pull it out and install the correct size cable". :lol: That's why you always include verbiage such as "Recommended upgraded feeder, customer declined" on the invoice.

 

[infinity]

Since you have a 30 amp, 120 volt feeder you could have any number of branch circuits as long as the calculated feeder load does not exceed 30 amps. It's likely that two fully loaded 20 amp circuits would not be permitted on the 30 amp feeder.

 

[romeo]

2 wire SE cable for Subpanel

2 wire SE cable for Subpanel

IMO, you cannot add the wire on the outside--art. 300.3(B). Also if this is seu cable then you wouldn't be adding an egc you would be adding a grounding conductor. I would walk from that job unless she was willing to pay for the wire to be replaced. You probably should have had that in your bid.

I totally agree.

 

[cadpoint]

Why are you'll even considering turning it into a circuit much less using it for a subpanel? (kinda missed #3)

Now the OP didn’t state what exactly what they had in the SEU!*

Wondering how I can make this work....
1. Do I run EGC to the main, along side of SEU?
2. Can I bond to cold water pipe located 2 feet away?
3. As long as the only load is 120 (20 amp), can I leave as is and bond the neutral/ground?

1. No. 303.3(B) Conductors of the Same Circuit
2. No. for a subpanel, but if you had SER with three CCC (insulted) and a bare conductor then yes. Plus your running a feeder on the line side so one would need all the wires. Grounding to H20 is applicable if all of 250.52 is followed.
3. No for a subpanel. Yes for a single 20A circuit 120. * “With Type SEU cables you still need to take the time to un-twist the neutral wires before you can begin terminating the conductors. Then, you have to re-twist the neutrals back together for termination. You can eliminate these two steps by switching to Type SER cables. Southwire makes both types available, in copper and aluminum, but why not shorten your installation by using Type SER cables instead of Type SEU.” http://www.southwire.com/residential/ser-seu.htm

Reflecting again on 2 & 3; This in two hot(s) and a non insulted wire from what I read at the sight. I’ve never heard of a bare neutral on the line side? I don’t know where that code is other to say Neutral from 100.