Conduit bonding jumper sizing

[hhsting]

I have plans which say following notes:

1. Install an insulated throat ground bushing on each metallic service entrance conduit. Bond to ground bus using conductor that is size based on Table 250.66

2. Install an insulated throat grounding bushings on each metallic feeder conduit. Bond to ground bus using conductor sized based on NEC Table 250.122 using the feeder overcurrent device size.

My questions are as follows:

A. For SERVICE entrance conduit ground bushing according to NEC 2014 are we not suppose to bond to ground bus with conductor size using Table 250.102(C)(1)? I looked at NEC 2014 section 250.92(B) but it says nothing about which table to use for bonding jumper sizing

B. For FEEDER conduit ground bushing according to NEC 2014 are we not suppose to bond to ground bus with conductor size using Table 250.102(C)(1) or is the conductor an equipment bonding jumper sized as mentioned in NEC 2014 Section 250.120(D) or something different?

Can someone please help above questions I am stuck.

 

[packersparky]

1. The supply side bonding jumper is sized using table 250.102(C). It used to be sized using 250.66. Probably an outdated reference in the specs.

2. Look at 250.102(D)

 

[hhsting]

1. The supply side bonding jumper is sized using table 250.102(C). It used to be sized using 250.66. Probably an outdated reference in the specs.

2. Look at 250.102(D)

Ok but what are insulated throat grounding bushing and what are they used for application wise? Can they be used for application such as NEC 2014 section 250.92(B) or 250.97 or not?

 

[packersparky]

That question you asked in a different post. https://forums.mikeholt.com/threads/insulated-throat-grounding-bushing.2558610/

 

[infinity]

Ok but what are insulated throat grounding bushing and what are they used for application wise? Can they be used for application such as NEC 2014 section 250.92(B) or 250.97 or not?

Yes. The insulated throat is required to comply with 300.4(G) when the conductors are #4 or larger. Please do not post the same question twice in two different threads.