ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
High current GFI vs regular GFCI
by HotLine1. 11/15/18 02:32 PM
This anti-theist is priceless!!!
by djk. 11/14/18 07:19 AM
Single phase and what you call it.
by dsk. 11/12/18 11:10 AM
220/230/240V 60Hz Systems
by Albert. 11/07/18 12:48 AM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
0 registered members (), 12 guests, and 30 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Disconnect Bonding #112933
11/30/01 12:29 AM
11/30/01 12:29 AM
Admin  Offline
OP
Administrator
Member
Joined: Oct 2000
Posts: 3,524
NY, USA
[Linked Image]
Quote
This is the secondary disconnect for the transformer in the other post ( Here ). (also removed) Note the two grounded conductors under one lug. This is now a violation in the '02 NEC. I am not sure if it was a UL listing violation or not at the time it was installed 12 years ago. Something else that is unorthodox. The conduit on the right comes from the transformer. Note the EGC loops through both ground bushings while the one coming out of the other conduit goes directly to the can. To each his own I say

-Nick



[This message has been edited by Webmaster (edited 11-30-2001).]

Tools for Electricians:
Re: Disconnect Bonding #112934
11/30/01 10:16 PM
11/30/01 10:16 PM
R
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
Is this really a violation of the new rule in 408.21 requiring individual terminals for grounded conductors in switchboards and panelboards? Is a fused disconnect within the scope of Article 408? Also even if the disconnect is within the scope of 408, is this really two grounded conductors? It looks a like a splice in a single grounded conductor to me. There still may be an issue if the terminal isn't listed for use with two conductors, but I don think it is a violation of either the letter or intent of 408.21.
Don(resqcapt19)


Don(resqcapt19)
Re: Disconnect Bonding #112935
12/01/01 10:48 AM
12/01/01 10:48 AM
N
Nick  Offline
Member
Joined: Aug 2001
Posts: 599
Riverside, CA
Good point Don.
Let me see if I have this straight. The reasoning behind the rule is if someone were to lift a neutral in a panelboard that was doubled up with another there would be a hazard of causing sever voltage imbalance at down stream loads, right? 408.21 only applies to switchboards and panelboards, Right? 408 does not cover disconnecting means making this an acceptable installation. (The lug is duel rated.) Lets say, hypothetically, that the load end of this feeder lands in a panelboard where it continues on to another panelboard via either a breaker or a bus tap. Now lets say the where the grounded conductors come together in this first panel from the disconnect and the sub panel, they are landed under the same lug. Would be a violation of 408.21 or not? How would this be any different electrically than the situation shown here? For that matter, what if this were a panel instead of a disconnect. It would then be a violation? Or is it not because it is a splice. Where do you draw the line in calling it a splice and two separate conductors? [Linked Image]

Re: Disconnect Bonding #112936
12/01/01 12:14 PM
12/01/01 12:14 PM
R
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
Nick,
With a feeder grounded conductor, there is no reason to have the same rule as for branch circuit grounded conductors. If the feeded grounded conductor is lifted you have lost the grounded conductor for the feeder circuit and have created a problem for any multiwire branch circuits fed by that feeder. The same thing happens if there are two terminations as would happen with only one termination. As long as the termination is listed for 2 conductors, I see no code or real problem with making a feeder grounded conductor in that way.
Don(resqcapt19)


Don(resqcapt19)
Re: Disconnect Bonding #112937
12/02/01 12:02 AM
12/02/01 12:02 AM
N
Nick  Offline
Member
Joined: Aug 2001
Posts: 599
Riverside, CA
Forgive me; I don’t have the ’02 code yet.
I understand and agree with your reasoning here Don but is that what the letter of 408.21 says? Does it distinguish between branch circuit and feeder neutrals?

Re: Disconnect Bonding #112938
12/02/01 09:48 PM
12/02/01 09:48 PM
R
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
The letter of the new rule applies to all grounded conductors in panelboards.


Don(resqcapt19)
Re: Disconnect Bonding #112939
12/10/01 11:20 AM
12/10/01 11:20 AM
N
Nick  Offline
Member
Joined: Aug 2001
Posts: 599
Riverside, CA
If the new section does not distinguish between branch and feeder, would you find this installation a violation or not? The lug is rated for the two conductors. One comes from a transformer the other goes on to another panel.
[Linked Image]

Re: Disconnect Bonding #112940
12/10/01 01:18 PM
12/10/01 01:18 PM
R
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
Nick,
I would call that a violation. If you lift the neutral wire going the other panel, you will create an open neutral for both panels.
Don(resqcapt19)


Don(resqcapt19)

Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
JoeKP
JoeKP
Berkley, MA
Posts: 144
Joined: March 2008
Show All Member Profiles 
Top Posters(30 Days)
Admin 8
Popular Topics(Views)
251,498 Are you busy
188,680 Re: Forum
178,382 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.029s Queries: 14 (0.006s) Memory: 0.9946 MB (Peak: 1.1542 MB) Zlib enabled. Server Time: 2018-11-16 05:33:52 UTC