NEC Table 250.122: Minimum Size Equipment Grounding Conductors for Grounding Raceway and Equipment

2021年3月2日 · If you turn to Section 250.122 in the 2020 NEC, you find information that has been helping electricians to size equipment grounding conductors (EGC) for longer than most electricians have been pulling wire.

2014年7月26日 · The size of the GEC and neutral is based on the size ungrounded service entrance conductors. There are tables for each but what is more important is you understand the difference in sizing. For example, what would the answer be to the following question:

If you use both raceway and wire-type EGC enclosed within, the size requirements still apply to the wire-type EGC. EGCs must be sized not smaller than shown in Table 250.122; however, the EGC is not required to be larger than the phase conductors [250.122(A)].

2024年11月21日 · If you increase the size of the circuit conductors then you are required to increase the EGC by the same proportional cross section. For a 20A circuit, the calculation is easy because the EGC is the same size as the circuit conductors.

2023年9月3日 · Learn how to size equipment grounding conductors. National Electrical Code (NEC) Section 250.122 rules the sizing of equipment grounding conductors. Table 250.122 displays the minimum conductor size for grounding raceways and equipment based on the ampere rating or setting of the circuit’s overcurrent protective device.

2009年1月7日 · I have a lighting relay panel which is fed with #6 THHN from a 3 pole 20 amp breaker. The lugs on the panel accept 400 kcmil-#6 AWG conductors. What size EGC is required? I say #12 due the lug size, others say #6 due to 250.122(B). Which is it?

2023年2月15日 · It is always best to perform this simple calculation to verify that the adjusted size of the EGC meets or exceeds the minimum requirements. Simply increasing the equipment grounding conductor size is not adequate in all cases. The minimum size wire-type EGC for a 400A feeder is normally a 3 AWG copper, according to Table 250.122.

The National Electric Code (NEC) defines the Equipment Grounding Conductor (EGC) as the conductive path or paths that provides a route for ground-fault current. This connects any non-current carrying metal parts of equipment together and to the system ground conductor or to the ground electrode conductor or both.

It is permissible to install electrical metallic tubing (EMT) and use it as an EGC without a conductor-type EGC installed. However, where we install a conductor-type EGC in a parallel feeder installed in EMT, it must be a full-size conductor EGC based on …