when grounding bushings

[bjdm829@fuse.net]

some elec typers are confused when and where u use g-bushings. i.e. don't forget transformers feeds, k.o's, and... please explain

 

[benaround]

line side serv. disco & over 250v 2 grd if conc or eccnt ko's

 

[jeremysterling]

line side serv. disco & over 250v 2 grd if conc or eccnt ko's

I admire your brevity!

 

[ibew441dc]

some elec typers are confused when and where u use g-bushings.

When trying to understand when Grounding/Bonding Bushings are required, one must understand where he/she is at in the electrical system. Many neglect the importance of the definitions in Article 100, and make incorrect assumptions as to the mandatory versus permissible practice, especially for Grounding/Bonding Bushings.

:smile:If you are confused I highly recommend a visit first to Article 100.....

1) service ( and all associated terms)
2) feeder
3) branch circuit

After Article 100 go to Part 5 Bonding in Article 250

After a close study of Part 5, especially 250.92 and 250.97, one should be able to accurately apply the general rules for Grounding/Bonding Bushings.

i.e. don't forget transformers feeds, k.o's, and... please explain

After reviewing the definitions and considering the sections listed above....is the transformer you mention a service or a feeder? Understanding where you are at in the system clears up a lot of confusion
(although maybe not all :wink.

Hope this helped:smile:

 

[infinity]

Bonding bushing aren't required for much except for concentric and eccentric KO's. Although there are additional requirements for service raceways and over 250 volts, bonding bushing are not required for either of those conditions. Bonding locknut's or bonding wedges may also be permitted.