208/120V service and fdr bushing

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hhsting

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I have 208/120V three phase system

Two questions:


1. For downstream of service equipment FEEDER conduit ground bushing according to NEC 2014 are we not suppose to bond to ground bus with conductor? We use Table 250.102(C)(1) for bond conductor size?

2. Also in service equipment incoming are service conduit I understand that service conduit need ground bushing bond to ground bus but outgoing in service equipment are feeder conduit. Should those outgoing conduits in service equipment require ground bushing and bond to ground bus? I looked 250.94 but still confuse
 
tom baker said:
Why do you think 120/208 feeders require bond bushings?
Click to expand...

I think No not feeder conduit dont??? but The confusing part is in your service disconnect incoming conduit is service but outgoing conduits in service disconnect do they need ground bushings for 208/120V?
 
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hhsting said:
I have 208/120V three phase system

Two questions:


1. For downstream of service equipment FEEDER conduit ground bushing according to NEC 2014 are we not suppose to bond to ground bus with conductor? We use Table 250.102(C)(1) for bond conductor size?
Click to expand...

raceways less than 250 volts to ground to not require bonding bushings (except those enclosing service conductors), but you can use them if you want. See 250.102(C) for sizing
2. Also in service equipment incoming are service conduit I understand that service conduit need ground bushing bond to ground bus but outgoing in service equipment are feeder conduit. Should those outgoing conduits in service equipment require ground bushing and bond to ground bus? I looked 250.94 but still confuse
Click to expand...
No, feeder and branch conduits to not require additional bonding if under 250 volts to ground.

Note there are other options besides bonding bushings, such as bonding locknuts. Everyone seems to go for bonding bushings not sure why, they are a pain.
 
electrofelon said:
raceways less than 250 volts to ground to not require bonding bushings (except those enclosing service conductors), but you can use them if you want. See 250.102(C) for sizing

No, feeder and branch conduits to not require additional bonding if under 250 volts to ground.

Note there are other options besides bonding bushings, such as bonding locknuts. Everyone seems to go for bonding bushings not sure why, they are a pain.
Click to expand...


Ok but I thought for feeders conduits downstream of service disconnect one uses NEC 2014 Section 250.120(D) to size bonding jumper from ground bus to ground bushing? Your saying 250.102(C)(1)? I don’t follow
 
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