Range and dryer circuits after an Automatic generator transfer switch

[desllc04]

In reviewing the code articles in 250-140 and 250-142, and the requirements for upgrading the feeder conductors, (recepts and pigtail) from the now load panel to those appliances once an automatic transfer switch with a service disconnecting mean is installed. Because of the risk of unwanted current through the appliance to another grounded item,(sink or countertop appliance) the old uninsulated conductor in the SE cable is not permitted to serve as the grounded conductor, (neutral).

Thoughts?

 

[Ponchik]

I hope I understood your question. If it is existing, I leave it alone. If new then 4 wire circuit.

 

[augie47]

Once an ATS or any service disconnect is added ahead of an existing service panel then the neutrals and equipment ground must be separated on any panels/equipment on the load side of the new disconnect. The AHJ might allow exceptions on existing wiring but that is a local jurisdiction call.

 

[Little Bill]

I've been allowed to tape the bare neutral with white tape in the panel and at the appliance. This was because it would have caused a lot of damage and cost to run new cables. The whole idea/concept is to prevent unwanted current flowing onto something conductive in case the bare neutral contacted a conductive surface. The tape would prevent that.

 

[Steve16]

If you are adding a transfer switch, creating a new service disconnect, and changing the former main panel to a 4 wire sub panel the NEC would require you to replace the existing SEU wire with a new 4 wire if you are on any code cycle prior to 2023.

2023 has added language that will allow these circuits to stay in the sub panel. I beleive the wording calls for you to tape the bare conductor white and land it on the grounded conductor bar in the sub panel. I may be paraphrasing a bit