Grounding bushing wire size #.

Status
Not open for further replies.
V

velezl

Member
We are installing a mdp of 1200a.we are feeding the panel from the bottom with a wierway with 4 3-1/2 cond.it is require to have a graunding bushing in all the chase niple and what is the # of the wire for bonding the bushing..
 
Is the wireway on the line or load side of the service?

For load side bonding jumpers take a look at 250.102(D)

For line side bonding jumpers take a look at 250.102(C)

Chris
 
Assuming service conduits, it depends on how you install the conductor. If you loop one conductor and catch all bushings then you need to add the total kcmil of one phase conductor in each conduit and size the single jumper per 250.66 unless the sum goes over 1100kcmil (cu) then it;'s 12=1/2% (see 250.102)
If you run and individual bond to each bushing then it's sized per 250.66 for the parse conductor in the individual conduit.
 
we have a mdp and in the bottom is the wierway flush with the mdp.it haves 4 chase nipl. and the wire are in parallel pasing thru the wier way to the mdp.

i know that the main bonding is 3/0 but if i go to the 250.122 it tellsme to use the brk size @1200 and is 3/0 and 250.66 it tells that i have to use acording to the wire size that is installed in this case is 350kcm and it is 3/0

iam confuse since i have the sevice bonding & equipment together.but for that bushing iam confuse.
 
250.66 is for service conductors (unprotetcted--ahead of your main)
250.122 is only for circuits which have overload protection.
 
velezl said:
we have a mdp and in the bottom is the wierway flush with the mdp.it haves 4 chase nipl. and the wire are in parallel pasing thru the wier way to the mdp.

i know that the main bonding is 3/0 but if i go to the 250.122 it tellsme to use the brk size @1200 and is 3/0 and 250.66 it tells that i have to use acording to the wire size that is installed in this case is 350kcm and it is 3/0

iam confuse since i have the sevice bonding & equipment together.but for that bushing iam confuse.
Click to expand...



Are the conductors in the raceways that the bushings are mounted on supplying the service disconnecting means, or are those conductors being supplied from a circuit breaker?
 
Status
Not open for further replies.
Top