Bonding Bushing how many?

[fobia]

Hi from Texas! If I run a paralleled metal raceways from a service disconnect to a panelboard or from the meter base to a service disconnect or panel, do I have to install bonding bushings at all 4 ends. 250.92(A) says that all service equipment non-carring metal parts (nipples) must be effectively bonded toghther.
A friend in the trade says that only one raceway should do, and if I do the knock with a "knock out set" I don't have to install bonding bushings,
is that what 250.92(B) means, Reading the code book creates more questions than answers, I need someone to translate!

 

[RUWired]

fobia,You need to bond each raceway on both ends.

(3) Any metallic raceway or armor enclosing a grounding electrode conductor as specified in 250.64(B). Bonding shall apply at each end and to all intervening raceways, boxes, and enclosures between the service equipment and the grounding electrode.

Translated means you need to bond all raceways up to the point that the grounding electrode conductor is made at.

Bonding jumpers meeting the other requirements of this article shall be used around concentric or eccentric knockouts that are punched or otherwise formed so as to impair the electrical connection to ground. Standard locknuts or bushings shall not be the sole means for the bonding required by this section.
Rick

 

[don_resqcapt19]

Rick,
These are service conduits and they would not contain the GEC. Bonding of service conduits is only required at one end by the NEC, however some utilities, like the one in my area, require that the service raceways be bonded at both ends.
Don

 

[benaround]

Fobia,

Service Equipment, read the def. in article 100, it needs to be all bonded.

If you are using paralleled metal raceways you need to bond both.

About the 'knock out' deal, you need to bond around concentric,or essentric

KO's if over 250vac to ground unless the equipment is rated as such.