garrisonm1
Member
- Location
- Maryland
Is a number 12thhn grounding electrode conductor permitted for a 15kva transformer, or is the minimum size number 8
#12 ground electrode conductor
- Thread starter garrisonm1
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ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: #12 ground electrode conductor
250.30 states that the GEC shall be sized off of table 250.66. The smallest GEC allowed in table 250.66 is #8 Cu.
250.30 states that the GEC shall be sized off of table 250.66. The smallest GEC allowed in table 250.66 is #8 Cu.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: #12 ground electrode conductor
The bonding jumper or grounded conductor - when the bonding point is at the first disconnecting means does not have to be larger than the largest ungrouned conductors....
250.30 (A)(6) Grounded Conductor. Where a grounded conductor is installed and the bonding jumper is not located at the source of the separately derived system, the following shall apply:
(a) Routing and Sizing. This conductor shall be routed with the derived phase conductors and shall not be smaller than the required grounding electrode conductor specified in Table 250.66, but shall not be required to be larger than the largest ungrounded derived phase conductor.
However the GEC from the transformer or disconnect can be smaller than 8 but would have to be in conduit, if metal its bonded at each end.
Use 6 or 4 for the GEC. I install a lot of 5 kw transformers, and use 8 awg from the transformer to the disconnect, then a 4 awg gec to the ge system.
[ October 14, 2003, 09:17 PM: Message edited by: tom baker ]
The bonding jumper or grounded conductor - when the bonding point is at the first disconnecting means does not have to be larger than the largest ungrouned conductors....
250.30 (A)(6) Grounded Conductor. Where a grounded conductor is installed and the bonding jumper is not located at the source of the separately derived system, the following shall apply:
(a) Routing and Sizing. This conductor shall be routed with the derived phase conductors and shall not be smaller than the required grounding electrode conductor specified in Table 250.66, but shall not be required to be larger than the largest ungrounded derived phase conductor.
However the GEC from the transformer or disconnect can be smaller than 8 but would have to be in conduit, if metal its bonded at each end.
Use 6 or 4 for the GEC. I install a lot of 5 kw transformers, and use 8 awg from the transformer to the disconnect, then a 4 awg gec to the ge system.
[ October 14, 2003, 09:17 PM: Message edited by: tom baker ]
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