Conduit Riser Bonding Bushing

[Jsim4109]

Does a GRC conduit riser, soley for the protection of a tray cable from an enclosure to the cable tray, which is fastened to the enclosure with standard locknuts need a bonding bushing attached to the cable tray? The tray cable has an equipment grounding conductor which is attached to the enclosure ground bar and is the effective ground fault current path.

 

[LEO2854]

Does a GRC conduit riser, soley for the protection of a tray cable from an enclosure to the cable tray, which is fastened to the enclosure with standard locknuts need a bonding bushing attached to the cable tray? The tray cable has an equipment grounding conductor which is attached to the enclosure ground bar and is the effective ground fault current path.

Here is part of the awnser but you need to read through 250 as well.

392.60 Grounding and Bonding.
(A) Metallic Cable Trays. Metallic cable trays shall be
permitted to be used as equipment grounding conductors
where continuous maintenance and supervision ensure that
qualified persons service the installed cable tray system and
the cable tray complies with provisions of this section. Metallic
cable trays that support electrical conductors shall be
grounded as required for conductor enclosures in accordance
with 250.96 and Part IV of Article 250. Metal cable
trays containing only non-power conductors shall be electrically
continuous through approved connections or the use
of a bonding jumper not smaller than a 10 AWG.

 

[Jsim4109]

Thank you. I forgot that we have also installed a single 4/0Awg insulated equipment grounding conductor (EGC) that is bonded to the tray every 100'. This same EGC leaves the tray, down the conduit riser and atatches directly to the enclosure grounding buss bar. I feel that since the GRC enters the enclosure through a hole we punched, uses standard locknuts and the ground buss is attached directly to the enclosure, the GRC riser does not need bonding bushings.

Can you confirm?

 

[LEO2854]

Thank you. I forgot that we have also installed a single 4/0Awg insulated equipment grounding conductor (EGC) that is bonded to the tray every 100'. This same EGC leaves the tray, down the conduit riser and atatches directly to the enclosure grounding buss bar. I feel that since the GRC enters the enclosure through a hole we punched, uses standard locknuts and the ground buss is attached directly to the enclosure, the GRC riser does not need bonding bushings.

Can you confirm?

That sounds good to me the RMC is going into punched holes so it should be fine IMO.:thumbsup: