The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
breaker meltdown
by sparky
09/27/16 07:30 PM
230 or 345 kV transmission lines?
by Vlado
09/24/16 09:33 AM
Electrical mast flashing product
by ThomasWinfrey
09/22/16 12:14 AM
What estimating software do you recommend?
by sparky
09/21/16 07:20 PM
"Dry Run" Inspection goes awry
by HotLine1
09/20/16 07:39 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
HotLine1 13
sparky 10
gfretwell 8
sparky66wv 8
Vlado 6
Who's Online
0 registered (), 64 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 2 1 2 >
Topic Options
Rate This Topic
#201108 - 05/11/11 09:22 PM 3 wire feeder
schenimann Offline
Member

Registered: 02/18/08
Posts: 194
Loc: Western North Carolina
I've got a customer who is selling his house. He had his home inspection. One of the things noted was a 3 wire feeder to a small sub panel for his furnace. This panel now has 5-6 breakers feeding lights, a waterfall pump with a timer, etc. It is fed from a 200amp sub panel that is fed with 4 wires with the grounds and neutrals separated. Obviously it is a code violation however when I explained to him the fix (cutting, patching, drilling) he decided to put it off for the new home owners. What are the potential hazards of this set-up if any?

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#201109 - 05/12/11 01:04 AM Re: 3 wire feeder [Re: schenimann]
noderaser Offline
Member

Registered: 03/01/07
Posts: 405
Loc: Portland, Oregon, United State...
Could be problems if the potential buyers have a home inspection; depending on how picky they are, they may ask that things like that be brought up to code as part of the terms of sale. This is especially true if they're looking at an FHA loan, they will want pretty much everything to be code-compliant, if it wasn't grandfathered in somehow.


Edited by noderaser (05/12/11 01:06 AM)
_________________________
http://www.hsiprodsvcs.com/

Top
#201111 - 05/12/11 08:52 AM Re: 3 wire feeder [Re: schenimann]
sparkyinak Offline
Member

Registered: 07/08/07
Posts: 1286
Loc: Alaska
I'm still working on my first cup of coffee. Something is not clicking in my brain. What is the violation? The grounds and neutrals are suppose to be seperate in a sub-panel
_________________________
"Live Awesome!" - Kevin Carosa

Top
#201112 - 05/12/11 09:03 AM Re: 3 wire feeder [Re: schenimann]
Niko Offline
Member

Registered: 08/17/06
Posts: 358
Loc: Campbell, CA
if you have two hots, (1) neutral, (1) EGC i don't see anything wrong with this installation. Assuming everything is installed correctly.

The home inspector may have added the rating of the breakers and saw that the size of the feeder doesn't match the total amp rating of the breakers so he/she called it a violation or a hazard.

Then again at the beginning of your post you mention a 3 wire feeder and changed it to 4 wires.



Edited by Niko (05/12/11 09:03 AM)
_________________________
Be kind to your neighbor, he knows where you live


Top
#201115 - 05/12/11 12:33 PM Re: 3 wire feeder [Re: schenimann]
Gregtaylor Offline
Member

Registered: 03/02/05
Posts: 212
Loc: Boise, Idaho, USA
So you have a 200a subpanel with a 4 wire feeder feeding another subpanel with a 3 wire feeder that was originally for the furnace only and now has 120 volt loads connected to it using the EGC as the grounded conductor. Is that right?
I'm sure that as someone able to recognize the code violation, you also recognize the hazard. You either have an uninsulated or undersized conductor being used as a current carrying conductor or you have no grounding at all.

Top
#201116 - 05/12/11 12:56 PM Re: 3 wire feeder [Re: schenimann]
Niko Offline
Member

Registered: 08/17/06
Posts: 358
Loc: Campbell, CA
If it is a cable type feeder and If the EGC is being used as a current carrying conductor it is a violation.

Then again, if the feeder is installed in a metallic conduit you still have a 3 conductor feeder but are using the metallic conduit as a EGC and have 2 hots and a neutral then your installation is ok. assuming the EGC is not being used as a current carrying conductor.
_________________________
Be kind to your neighbor, he knows where you live


Top
#201117 - 05/12/11 02:17 PM Re: 3 wire feeder [Re: schenimann]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
The danger of having a 3 wire feeder with a shared EGC and neutral is that you end up with voltage on your ground. Before the exception was removed for separate building feeders the rationalization was that you were providing a local ground electrode system, much like what happens with the service. The fact is, if you actually look at the GEC in your house, you will usually see neutral current there too and that is also demonstrating a voltage drop in that 3 wire SE cable neutral/ground.
The problem inside your house is that you will see a voltage gradient between the grounded case of equipment from this 3 wire sub and a truly grounded item like a cold water pipe in a metal plumbing system.
_________________________
Greg Fretwell

Top
#201119 - 05/12/11 07:31 PM Re: 3 wire feeder [Re: schenimann]
schenimann Offline
Member

Registered: 02/18/08
Posts: 194
Loc: Western North Carolina
thanks for the help. I did explain to him that it was a violation, however, in the end it is his decision to have it repaired or leave it. All I can do is inform. Whenever he gets a potential buyer, I guess they will make the final decision as to the repair.

The feeder is a 3 wire cable with the egc going back the egc bus in the main.

Top
#201122 - 05/13/11 03:37 PM Re: 3 wire feeder [Re: schenimann]
mikesh Offline
Member

Registered: 06/07/06
Posts: 614
Loc: Victoria, BC, Canada
Is there a duty to report clause in your state's legislation? The province of BC's Safety Standards act makes that knowledge reportable and if it could be proved you did not report it to the inspection authority you could become label for damages should anyone get hurt. Using the bond wire as a current carrying conductor can set up a shock hazard to non current carrying parts of the bonding system.
I hate talking to my neighbours about electrical matters and tell them to stop before they reveal anything I may have a duty to report.
It is a little like asking the policeman living next door over to your pot party ;-)

Top
#201125 - 05/13/11 11:48 PM Re: 3 wire feeder [Re: schenimann]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
In the US I do not know of any law that says you have to report a code violation but if you, as a professional, working on it, may have the obligation to fix it if you touch it. This all gets back to those "rehab" or "existing building" codes we talk about here.
_________________________
Greg Fretwell

Top
Page 1 of 2 1 2 >



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals