ground wire size

[zam]

Can the size of the ground wire be bigger than the wire size of the current carrying conductors? Example: 4#12 & 1#8 ground in 3/4" conduit. Thank you.

 

[luckylerado]

Can the size of the ground wire be bigger than the wire size of the current carrying conductors? Example: 4#12 & 1#8 ground in 3/4" conduit. Thank you.

It can be. It is not required to be.

250.122 Size of Equipment Grounding Conductors
(A) General. Copper, aluminum, or copper-clad aluminum
equipment grounding conductors of the wire type shall not be
smaller than shown in Table 250.122, but in no case shall they
be required to be larger than the circuit conductors supplying
the equipment....

 

[infinity]

Can the size of the ground wire be bigger than the wire size of the current carrying conductors? Example: 4#12 & 1#8 ground in 3/4" conduit. Thank you.

Yes, we did a Broadway theater where by deign all the audio and video power required a #12 phase/neutral conductors and a minimum #8 EGC.

 

[zam]

Can the size of the ground wire be bigger than the wire size of the current carrying conductors? Example: 4#12 & 1#8 ground in 3/4" conduit. Thank you.

This question came up while designing the secondary side of a 15 KVA transformer, where I referred to Table 250.66 for "Service Ground size".

 

[infinity]

This question came up while designing the secondary side of a 15 KVA transformer, where I referred to Table 250.66 for "Service Ground size".

What are you referring to when you say secondary side of a transformer, the SSBJ? And does T250.66 use the term "service ground size"? Correct terminology is important when try to answer a question.

 

[Carultch]

Can the size of the ground wire be bigger than the wire size of the current carrying conductors? Example: 4#12 & 1#8 ground in 3/4" conduit. Thank you.

It is rare that it is required to be smaller than the main wires in anything 400A and less. There is no problem with ground wire being larger than it needs to be by the NEC.

One place you might see the ground wire needing to be bigger than the CCC's, is when you have numerous parallel sets. We're talking thousands of ampere circuits. The amps can be divided among each parallel set's current-carrying conductors, but each conduit requires a full size equipment ground.

 

[ActionDave]

It is rare that it is required to be smaller than the main wires in anything 400A and less....

Huh?