PDA

View Full Version : grounding

m2oliva
12-17-2003, 09:54 AM
When doing a service in pipe you must bond the the side of the pipe entering the meter but what about the side at the weatherhead. ?
bennie
12-17-2003, 11:05 AM
The reason for bonding the riser to the neutral bus is to provide a low impedance current path to cause a ground fault to burn clear, or activate the primary cut out fuses.

One connection point is all that is necessary.
earlydean
12-17-2003, 04:14 PM
Do you really think a fault in the riser pipe would blow the primary fuse? Not likely. By bonding the pipe, however, the pipe is at the same potential as the surrounding metal enclosures, and therefore less of a shock hazard.
iwire
12-17-2003, 05:23 PM
If it is all metal conduit one end will do it.

If you do it like us, metal raceway at both ends, PVC in the middle underground you will need bonding at both ends.

Remember to size this bonding jumper properly as a line side bond.
tom baker
12-17-2003, 06:14 PM
A change for the 2002 NEC allows metal raceway containing service entrance conductors to be bonded to the utility service neutral at the pole, see 250.102(E) exception. It is usually easier to use sch 80 PVC on a pole, or fiberglass in cold climates.
bennie
12-17-2003, 06:20 PM
A fault on the supply side can only do two things, burn clear or activate the primary fuse.

I have seen many fuses expell on a supply line fault. It is not likely to occur on a residential bank.
iwire
12-17-2003, 06:26 PM
Originally posted by tom baker:
A change for the 2002 NEC allows metal raceway containing service entrance conductors to be bonded to the utility service neutral at the pole, see 250.102(E) exception. It is usually easier to use sch 80 PVC on a pole, or fiberglass in cold climates. In this area the POCOs will only except RMC up the pole with a large radius RMC sweep, some want 10 more feet of RMC underground.

Most of the POCOs would expect us to provide a ground clamp and they would take it from there to their neutral / ground.
hurk27
12-18-2003, 02:39 AM
This is all news to me. I have never seen a riser pipe for a overhead service bonded, other than the connection it gets from where it is threaded into a hub on the top of the meter, and through the 4 bolts that secure the hub to the can. I'm I missing somthing?
iwire
12-18-2003, 04:14 AM
No I don't think you are missing anything. :)

I read the opening post wrong :o and thought m2oliva was talking about a riser pipe going up a pole, not a riser up out of a meter.