3 wire no ground SE cable feeder to sub

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flatlander

Senior Member
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Diamond bar, CA , Tempe AZ
I ran into a situation scoping a panel replacement. I found 3 wire cloth covered SE type cable with no ground from the meter /main breaker to a sub panel inside 100 feet away.
The neutral is bonded to the can.
Built in the 60's
Was this ever compliant?
 
Something else to concider is that the main disconnect of that era also may only have lug positions on the neutral buss have ( line in, grounding electrode conductor, line out ) which kinda led people to do things the way they did.
So you may find yourself trying to figure out where to put that 4th wire.
 
I thought that a 3-wire system was permitted on single family dwellings, at one time. As was 3 -wire feeders to ranges & dryers. 4-wire first require on manufactured homes, then latter on houses :?
 
Sounds like old cloth covered NM without a ground.

Take a look at the code for _adding_ a ground conductor to an existing circuit. If this subpanel is near the GEC it might be easy and fast.

However, in general, the labor for adding a ground conductor is most of the way to replacing the cable. The materials cost is lower, of course, but the labor cost often dominates.

If this is old cloth covered cable, it might pay to replace the whole thing anyway.

-Jon
 
flatlander said:
What do you mean I have no choice?
The customer does not want to do the job. What am I supposed to do? Call the inspector and have it red tagged?


Boy that will get me the job!:rant:


It dont think its NM as others have thought. It's #1 AL . Don't think they made it that large.
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Are you sure its AL and not tinned copper? Lots of very old cable for sp's, dryers and ranges is similar to what you described. Cloth jacket/rw/tw insulation w /silver looking conductors, that is actually tinned copper....

By the time AL hit the scene, most jackets were trending towards being pvc.

I would go with replacing the feeder and be done w/ it. The customer needs to have it explained to him that the cable being reconnected to a new panel as is a code violation, no ifs, ands, or buts about it.

OFC, if persuasion fails, there is always 250.130(C).... however, not sure about that one in this case- you are not doing a branch ckt or rec replacement, so don't know at the moment if that would help you- not near book to give you the best answer.
 
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flatlander said:
Wonderful. So I want to replace the panel is it legit to run a thhn ground alongside the SE cable or do I need to run a new feeder?
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winnie said:
Take a look at the code for _adding_ a ground conductor to an existing circuit. If this subpanel is near the GEC it might be easy and fast.

-Jon
Click to expand...

user 100 said:
.... however, not sure about that one in this case- you are not doing a branch ckt or rec replacement, so don't know at the moment if that would help you- not near book to give you the best answer.
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Got back to the book:

While its been done a lot and gets done all the time, the legality of adding a separate egc to an old cable type 3w feeder is iffy/open to interpretation-

215.6 tells you that the egc for a feeder must comply with 250.134 and 250.134(B) says that the EGC must be routed within the "same raceway, cable, or otherwise run with the circuit conductors."

The exception to 250.134(B), which is 250.130(C), is for when you add an egc for branch circuit ext'ns / replace old 2w rec with grounding type- doesn't apply in your situation.

So an appropriately sized THHN (see table 250.122) run right next to the feeder might be considered "otherwise run with the circuit conductors."
 
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flatlander said:
Sorry no pictures. Probably won't be able to get them either as the customer won't go for replacing the cable.

The cable is cloth covered with black, red,white.
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flatlander said:
What do you mean I have no choice?
The customer does not want to do the job. What am I supposed to do? Call the inspector and have it red tagged?


Boy that will get me the job!:rant:


It dont think its NM as others have thought. It's #1 AL . Don't think they made it that large.
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dkidd said:
Do it right or walk away. :happysad:
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I think I had answered this. No job , does not want to replace feeder, customer on their own.
 
JDB3 said:
I thought that a 3-wire system was permitted on single family dwellings, at one time. As was 3 -wire feeders to ranges & dryers. 4-wire first require on manufactured homes, then latter on houses :?
Click to expand...

You are correct. 3 wire was allowed to ranges and dryers. 4 wire now.
 
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