Grounding Frames of Ranges...

[smallfish]

An electrical contractor upgraded and relocated a homeowner's electrical service, and in so doing, ran a new three-wire cable to the original range plug. I inspected his work and I'm finding it hard to interpret the following Sections of code.

The 2005 NEC Section 250.140 requires that frames of ranges and clothes dryers shall be grounded in the manner specified by 250.134 or 250.138. (That's the easy part.)

Section 250.138 Cord-and-Plug-connected Equipment (which is what this electric range is) requires non-current carrying metal parts of cord and plug connected equipment, if grounded, shall be grounded by one of the methods in 250.138(A) or (B). (This is the hard part.)

So, what does it mean, "if grounded"?

Could it be that this old electric range is not grounded and does not require grounding with the use of a four wire cable?

Thanks

 

[Dennis Alwon]

An electrical contractor upgraded and relocated a homeowner's electrical service, and in so doing, ran a new three-wire cable to the original range plug. I inspected his work and I'm finding it hard to interpret the following Sections of code.

The 2005 NEC Section 250.140 requires that frames of ranges and clothes dryers shall be grounded in the manner specified by 250.134 or 250.138. (That's the easy part.)

Section 250.138 Cord-and-Plug-connected Equipment (which is what this electric range is) requires non-current carrying metal parts of cord and plug connected equipment, if grounded, shall be grounded by one of the methods in 250.138(A) or (B). (This is the hard part.)

So, what does it mean, "if grounded"?

Could it be that this old electric range is not grounded and does not require grounding with the use of a four wire cable?

Thanks

If the EC ran a new feeder to the range then he would need to run a 4 wire feeder to it and change the cord on the range to a 4 wire.

The old range is grounded but it using the neutral as the grounded and grounding countor. No longer is that code compliant