Thread: Question about upgrading old wiring.

My client wants to install a kitchen in the basement, planning to put in a rental suite. The house is 60 years old and has a 1960's breaker panel, 100 amp service. He has barely or not enough there to run two electric ranges and 2 washer dryer units, plus electric baseboard heat. He calls in an electrician to evaluate the situation and knows probably there will be a need to increase the service.

The electrician recommends new service and a new panel, no surprise there, but also says there is a need to replace the 3 wire feeder from the old panel to the old kitchen range outlet upstairs. This will add a great deal to the cost of the upgrade. They are not renovating the old kitchen.

My question. I understand any new work needs to meet the current code standards. If the old wiring is not damaged, is this upgrade of the range supply cable really required?

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Originally Posted by John Kogel

My question. I understand any new work needs to meet the current code standards. If the old wiring is not damaged, is this upgrade of the range supply cable really required?

John,

You really did not give enough information to make an 'informed' answer, so I will make an 'uninformed' answer based on the condition I state.

When the electrician replaces the electrical service they will likely be connecting the range circuit from someplace other than the service equipment, where it is now (or should now be).

The exception for the three wire branch circuit to the range and clothes washer is based on that circuit originating at the service equipment, not at a distribution panel downstream from the service equipment.

Anyway, that is my 'uninformed' answer under that stated condition ... presuming (of course) that condition applies.

Just my opinion John

It used to be 3 wire was fine In The USA. The NEC disallowed it for any 'new construction' in 1996 plus when changing to new stoves there is a list of requirements before you can use the existing 3 wire otherwise a 4 wire must be installed.

It is possible the electrician is going by local code requirements that a service upgrade requires these type range circuits be upgraded to 4 wire. My question is though if there are electric dryers they likely are also 3 wire so why not those also?

In my area a service upgrade does not require it to be replaced unless it is not code compliant to pre 1996.

It is also possible that the existing branch circuit wiring is not meeting code for a 3 wire branch circuit. For instance it may be an nmd cable using the bare equipment ground as neutral.

OK, I've found a couple of pics. Yes it is a bad panel, don't everybody jump on me.
It has some modern Stablok breakers in it.

Jerry, yes, the old FP, (FedPacific before they became Federal Pioneer) service panel will be taken out, so the old wiring will be swapped over to the new. I am perplexed here because I have seen service changes done multiple times in other houses without a complete cable change.
In fact, this old feeder could possibly date back to the original fuse panel. It is encased in flexible conduit as we see in the pics. A modern range is in use in the old kitchen, so I suspect the outlet has been changed or the cord has been changed maybe?

Roger, the dryer cable is newer 4 wire, no problemo.

John

Looks ok to me but just based on what I see it appears to be aluminum wiring could that be the reason?

Older armored cable versions/standards provided less than sufficient by todays standards bonding and undersized grounding conductors,
depending on the vintage.

Perhaps for this reason the EC may not connect same to a newly installed panel which must meet today's standards and wiring methods. Further mention of the other end of this range circuit is a newer appliance. Suspect its rating is 120/240 or 120/208 and not 240, IOW draws unequal amp on L1 vs L2. The power authority likely wouldn't permit same to be connected to new panel unless proper conductors and wiring method employed for the appliance circuit to be sufficient for the in-place appliance.

IIRC your present requirements include separation of grounding and grounded conductors at all installations not just "downstream" of the "service equipment".Presume there will be a means to disconnect all electrical to the structure, "upstream" from the two new panels proposed to be installed.

Aluminum multistrand wire is not a problem. The lack of a grounding lead is.

Thanks HG. Yes there will be a new main breaker which will be the main disconnect. The service comes into this panel from the meter on the left. The branch circuit grounds in this panel are just twisted in a couple of knots at the lower right, so it was a piss poor install to begin with. Good riddance to it.

The present range has a light bulb, controls, and a receptacle which all operate on 120 v, but I don't see a problem with the wire size here. But I see your point, can't ground the neutral at the appliance. Luckily, I am not involved and will accept that the electrician thinks the AHJ wants to see proper grounding to the stove.

Thanks all. This is one more issue I will have to bring to my clients' attention when they are buying an older house.