Sizing Equipment grounding conductors

[wmeek]

If you size a motor branch circuit ocp per code. Does the equipment grounding conductor have to be size to the overcurrent device in this situation or just to the Full load current . What I have is:
20hp motor at 54A x 250% = 135A up it to 150A
Conductor 54A x 125% = 67.5A or a #4 Thhn conductor for phase conductors
What size would the grounding conductor have to be per code.

 

[jumper]

I think it should be sized per OCPD. T250.122= #6 CU

 

[raider1]

I agree with Jumper, the EGC should be sized on the motor branch circuit short circuit and ground fault protective device rating.

250.122(D) is the code reference.

Chris

 

[iwire]

I agree with Chris but not Jumper. :grin:


OK I agree with both of them and will add this ...

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.

 

[wmeek]

Thanks

 

[jumper]

I agree with Chris but not Jumper. :grin:


OK I agree with both of them and will add this ...

I do not blame you, that dude makes some crazy posts.:grin:

I hear that he tries, but I think he may not be the brightist kid on the block.

 

[mbeatty]

I do not blame you, that dude makes some crazy posts.:grin:

I hear that he tries, but I think he may not be the brightist kid on the block.

It's great to have a sense of humor, especially when speaking about yourself.