Grounding Bushings

[Duane @ Cougar Electric]

I have read in 300.4(F), that you must use an insulated fitting when the conductors are #4 AWG or larger. My question is, when do you need to use a grounding bushing? Where is it in the code book?

 

[bphgravity]

Chaeck out Part V. Bonding in Article 250 of the NEC.

 

[infinity]

There aren't many situations where a bonding bushing is actually required.

 

[raider1]

The most common need for a bonding bushing is on the line side of a service. Take a look at 250.92(B) for methods of bonding at a service.

Chris

 

[infinity]

The most common need for a bonding bushing is on the line side of a service. Take a look at 250.92(B) for methods of bonding at a service.

Chris

That's true, but even then a bonding bushing isn't required. You could use a bonding wedge or a bonding locknut to satisfy the requirement, provided the KO is the same size as the raceway.

 

[earshavewalls]

Mostly with concentric and sometimes eccentric knockouts and metal conduit per Article 250.92(B). 2005 NEC

 

[raider1]

That's true, but even then a bonding bushing isn't required. You could use a bonding wedge or a bonding locknut to satisfy the requirement, provided the KO is the same size as the raceway.

Agreed, In my area a bonding bushing is easier to get then a bonding wedge or bonding locknut. When you ask for a bonding locknut, or bonding wedge at the local supply house they usually just give you a funny look and give you a bonding bushing.

Chris

 

[derf48]

Two other areas need consideration. First, 250.97, bonding for over 250 volts. Second, 250.100, bonding in hazardous locations. Also check out 501.30, 502.30, and 503.30 for the locations called out to be bonded in 250.100, from the classified area all the way to the point of grounding for service equipment or separately derived system.

Fred

 

[benaround]

Also, underground PVC feeders that change over to RMC to penatrate the

slab,or the earth for that matter, need to bond that metal peice.