e57
Senior Member
- Location
- San Francisco, CA
I did bring this up very early in this thread - a point that seems to have gotten lost, but apparently not the actual question of the OP...What is the UL listing category for an offset nipple? If the category is not one of the wiring methods listed in 230.43, then you can't even use the offset nipple on the line side of the service disconnect.
Somehow you think the effects of this type of fault are ONLY going to go through one conduit to one place... On the other ends of the grounded service conductor there are a whole bunch of other grounding electrodes in other building. Are you telling me that this type of fault current is not going to find its way down this path in whole or in part? Care to prove wrong me on that? If not - how is that not different?It amazes me that you point to an example that clearly demonstrates that when the Code wants a raceway bonded on both ends that it's clear in doing so as a proof to your belief - it actually proves the exact opposite point.
Lightning is a high frequency event and the GEC is designed to give that event a path to earth. Therefore, ferrous raceways containing a GEC have to be designed to limit that choking effect.
Without making specific exceptions for service risers or laterals (which do not seem to be in the NEC style manual) certain raceways like those to a weather head would need an exception if written that way - 'Both ends - except this and that....'It is entirely different than a ground fault, making those provisions at an offset nipple in a service is not necessary, so it's not required.
250.64(E) is explicit that you must bond both sides of that raceway. If they wanted us to bond both sides of a raceway or nipple in service equipment, they would not make any bones about demanding it.
What ignorant power company employees, Frank the Barber down the street, or untrained/belligerent inspectors want to see is not relevant in the discussion. What is relevant is what the NEC requires, and does not require.
It clearly does not require bonding on both sides of this nipple between the meter socket and service disconnect, because if it were required, it would be specifically required the way that 250.64(E) does.
Look - I know I'm pissing in the wind.... :roll: I have not changed anyones mind here or anywhere else that I know of. (And maybe especially yours... ) And I doubt I will - but why not try... Because it makes a lot of sense to you - it doesn't to me - and yes I think this particular code is flawed. Sure a lot of educated people think its just fine, and fits the wording - I don't...Glad I was not the only one that thought that.
You have two paths of current (normal operating current, fault current of all kinds) and little way to change that in most of the situations I'm in limited to with RMC - Which is why it is a pet peev of mine. Am I going to roll over and play dead?
One path of current - the neutral is fine, add another path that sucks and does not fit the intent or wording IMO - then they both suck... Is it not a contradiction to 250.06?
(B) Method of Bonding at the Service. [FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]Electrical continuity at service equipment, service raceways, and service conductor enclosures shall be ensured by one of the following methods: [/FONT][/FONT]
Note: The word "Bonding" is not in the body of the code. "Electrical Continuity" is the 'method of bonding' at three different things... And by one of four different methods to follow... (BTW the grounded service conductor is not mentioned above.)
[FONT=Times New Roman,Times New Roman]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman](1) Bonding equipment to the grounded service conductor in a manner provided in 250.8 [/FONT]
"Bonding equipment" - not raceways, or enclosures, but "Bonding equipment" (a verb and a noun) to (a verb) the grounded service conductor. (another noun) Sure - "Equipment" - is a general term, but raceways are not mentioned in the definition... But - It does not say to bond anything else to it, or to use the grounded service conductor for continuity to anything else.
Self-explainitory...(2) Connections utilizing threaded couplings or threaded bosses on enclosures where made up wrenchtight
Self-explainitory...(3) Threadless couplings and connectors where made up tight for metal raceways and metal-clad cables
Self-explainitory...(4) Other listed devices, such as bonding-type locknuts, bushings, or bushings with bonding jumpers
Please note that there is no 5th method. The grounded service conductor is not listed as a method on its own.
[/FONT][/FONT]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.
If the grounded service conductor is not on the list of methods of ensuring continuity - then using regular lock nuts on one side of the conduit is not either IMO.
(*FYI - 'over-sized,' will be added here in '11 NEC to make sure people bond past reducing washers...)