grounding bushings required?

[wireman1]

are grounding bushings required in both panels of a step down transformer 480 volt to 208/ 120 volt . from the 480 panel the feed to the transformer is in greenfield, from the transformer the 208 /120 feed also is in greenfield does each feed require a grounding bushing to be used on one side or both or is none required what part of article 250 would address this we are on the 2008 code thanks

 

[augie47]

IMO, No grounding bushings are needed if the unless the install meets the criteria of 250.118 (5) since the FMC is not a grounding conductor there is no reason to bond back to it.

 

[Canton]

are grounding bushings required in both panels of a step down transformer 480 volt to 208/ 120 volt . from the 480 panel the feed to the transformer is in greenfield, from the transformer the 208 /120 feed also is in greenfield does each feed require a grounding bushing to be used on one side or both or is none required what part of article 250 would address this we are on the 2008 code thanks

This is one of the most misunderstood installations in our trade. I have heard on jobsites that the transformer is creating a New Service and we have to bond all the raceways! :lol: The only transformers you should be bonding any raceways our those that are service related. Your run of the mill SDS needs no bond bushings anywhere unless you have a strange install (cable tray to pipe, concentric ko's, your GEC to the transformer, etc.)

As Augie pointed out, FMC is only good for 20 or so amps, Liquid tight I think is 60 amps as a EGC. That's the funny thing...most of our SDS's have FMC installed as the raceway......your better off putting a bond bushing on a piece of PVC....:blink:

I love those urban TRADE legends.....Bond bushings everywhere....don't cross line and load in a disconnect.....and so on...