SureFire
Member
- Location
- Wake county, NC
- Occupation
- retired IT Systems Engineer
Background
Because you were gracious enough to allow me to post my NEC question to this forum, I thought I would share the answer my AHJ gave to me. The previous post and the NEC references are repeated below so you do not have to find the original post.
Answer
I had an onsite conference with a single trade electrical inspector. The single trade electrical inspectors in my jurisdiction have a more in depth knowledge of electrical than our multi-trade inspectors.
I discussed with him the information listed in the previous post, which is duplicated below. His response, which I am paraphrasing, was … No, 250.130(C)(4) cannot be used to ground a kitchen range to the EGC of another branch circuit. He stated that 250.140 states the grounding of the frames of ranges must be done in a manner specified in either 250.134 or 250.138. He said of the two, 250.138 Cord-and-Plug-Connected equipment is what would apply in this situation. And that 250.138(A) states the EGC [must] run with the power supply conductors. Therefore, attaching a range’s EGC to a different branch circuit would violate the ‘run with the power supply conductors’ requirement.
That’s it. Nothing else. I just wanted to share the answer.
Previous Post
Background:
Single family detached residence built in 1977. Electric range is wired as explained in the exception stated in 250.140. i.e. There is no EGC in the dedicated branch circuit for the range. Therefore, the frame of the range is bonded to the grounded conductor. Circuit breaker is 2-pole, non-GFCI, 50A. Let’s call this circuit A.
There is another branch circuit very near the range whose conductors, hot, neutral, and ground, are 10AWG copper. Let’s call this circuit B. Per Table 250.122, a 10 AWG copper conductor can be used as the EGC in a branch circuit up to and including 60A.
Both branch circuits originate from the same load center. The load center and the range are on opposite ends of the house. No easy crawl space, basement or attic access.
p.s. Because of extensive damage from hurricanes, our state is still using NEC 2017.
Question:
Can 250.130(C)(4) be used to do the following?
Because you were gracious enough to allow me to post my NEC question to this forum, I thought I would share the answer my AHJ gave to me. The previous post and the NEC references are repeated below so you do not have to find the original post.
Answer
I had an onsite conference with a single trade electrical inspector. The single trade electrical inspectors in my jurisdiction have a more in depth knowledge of electrical than our multi-trade inspectors.
I discussed with him the information listed in the previous post, which is duplicated below. His response, which I am paraphrasing, was … No, 250.130(C)(4) cannot be used to ground a kitchen range to the EGC of another branch circuit. He stated that 250.140 states the grounding of the frames of ranges must be done in a manner specified in either 250.134 or 250.138. He said of the two, 250.138 Cord-and-Plug-Connected equipment is what would apply in this situation. And that 250.138(A) states the EGC [must] run with the power supply conductors. Therefore, attaching a range’s EGC to a different branch circuit would violate the ‘run with the power supply conductors’ requirement.
That’s it. Nothing else. I just wanted to share the answer.
Previous Post
Background:
Single family detached residence built in 1977. Electric range is wired as explained in the exception stated in 250.140. i.e. There is no EGC in the dedicated branch circuit for the range. Therefore, the frame of the range is bonded to the grounded conductor. Circuit breaker is 2-pole, non-GFCI, 50A. Let’s call this circuit A.
There is another branch circuit very near the range whose conductors, hot, neutral, and ground, are 10AWG copper. Let’s call this circuit B. Per Table 250.122, a 10 AWG copper conductor can be used as the EGC in a branch circuit up to and including 60A.
Both branch circuits originate from the same load center. The load center and the range are on opposite ends of the house. No easy crawl space, basement or attic access.
p.s. Because of extensive damage from hurricanes, our state is still using NEC 2017.
Question:
Can 250.130(C)(4) be used to do the following?
- Replace the NEMA 10-50 receptacle with a NEMA 14-50 receptacle.
- There will be two cables going into the NEMA 14-50 receptacle. The original 3 wire, 4 AWG aluminum cable. And a new 10-2 with ground copper cable. The hot and neutral conductors of the 10-2 will be capped off and not used. The 10-2’s EGC will be connected to the ground terminal screw of the NEMA 14-50 receptacle.
- The other end of the 10-2 cable will be joined to circuit B inside an existing J box. The hot and neutral conductors will be capped off and not used. The EGC will be connected to the EGC of circuit B.
- Inside the J box, label the new 10-2 as ‘Kitchen range EGC only’
- Replace the range’s power cord with a NEMA 14-50 power cord.
- Unbond the ground and neutral in the range.
- Replace the 50A breaker with a 50A GFCI breaker.
- In the circuit directory (the documentation showing what each breaker protects) for the load center, make a note that the EGC for the kitchen range is connected to circuit B.
