Dishwasher tripping GFI. Help please.

Reply

  #1  
Old 10-06-11, 08:34 AM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
Dishwasher tripping GFI. Help please.

Hello All,
I recently installed a new dishwasher in my Inlaws second home (moving) and need some help troubleshooting. It' an older home that has all circuits loaded up, with exception of one as I used.

I pulled the power off of a hall light which also has two fans (no light kits) on that circuit (15 amp). Since there was no ground available and not practical in running one; I installed a GFI under the sink and used a 14/3 AC plug wire for the dishwasher.

My inlaws are in town and ran the dishwasher twice but each time the GFI tripped at some point during the drying cycle? They cannot say whether it trips immediate or after some period when heating.

1) That circuit should have less than 10 amps on it as the dishwasher only draws 6 total (1.5 pump, 4.5 heater). The two fans(new) and one hall light should be no more than 4 amps total.
2) The 14/3 plug I used was 5 ft. long which exceeds the recommended max. length in the dishwasher manual, but only slightly. Could this be an issue?
3) When installing I tested the dishwasher with direct power and no issue. It only trips the GFI not the 15amp breaker. So nothing else is affected.

Any suggestions?
 
Sponsored Links
  #2  
Old 10-06-11, 08:46 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,594
I think your dishwasher is leaking current somewhere.

You have several other issues; the DW should not be sharing the other circuit, you extended a non-grounded circuit and it does not sound like you used the appropriate cord either. Additionally the electric code requires DWs to utilize a grounded circuit.
 

Last edited by pcboss; 10-06-11 at 09:10 AM.
  #3  
Old 10-06-11, 08:48 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,058
Best solution is to install a new grounded circuit from the main panel or nearest sub panel. A GFCI is not required but the fact it trips a GFCI indicates there may be a fault in the dishwasher. If left un-repaired there may be an increasing danger to persons using it. It should be checked by an appliance repair person. Before doing anything though I would try a lamp or other device in the GFCI to see if it still trips. You may want to swap out the GFCI with a new one. You did wire both the white and black to the line side didn't you?
 
  #4  
Old 10-06-11, 11:37 AM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
Thanks for the input.

ray2047: Yes I wired to the line side only on the GFCI. A sticker comes over the load side (power to other outlets) which I left untouched as nothing is coming off of the dishwashers GFCI.
I will test the GFCI with a cut off saw or something which draws well over 6amps to see if it trips.

pcboss: Thanks for your help but consider the following....
1) Yes, the dishwasher should be on it's own circuit but there are none available. Everything, outside/inside panel box, is full and quite common on older homes. The circuit I chose has the least amount on it, which is very little. As stated, including the dishwasher there should be no more than 10 amps max.
2) The plug wire I used is 14/3 which is rated for 15amp as most of the house wiring. So the cable I used is capable, legal, and common way of wiring a dishwasher other than direct wire.
3) The NEC code has many exceptions and as I researched the issue. As I understand from research and forumn interaction, I should be ok with utilizing a GFCI even though it has no ground. In fact one expert claim it's even safer because the GFCI will immediately cut the power versus attempting to direct a short to ground. Go HERE for the specifics.

Receptacle replacement.

What happens when you're working at a previously unprotected location that now requires GFCI protection? It's no longer acceptable to replace an old, unprotected receptacle with a new, unprotected receptacle. Per 406.3(D)(2), you now must install a GFCI-protected device.

What if you come across a non-grounding type receptacle or an old 2-wire NM cable without a ground? These receptacles can be replaced with one of the following:


Another non-grounding type receptacle.


A GFCI-receptacle, if marked No Equipment Ground. (as I did)


A grounding type receptacle, if GFCI protected and marked GFCI Protected and No Equipment Ground.



The equipment-grounding conductor plays no part in the operation of a GFCI, so it will provide ground-fault protection even on a 2-wire circuit without an equipment-grounding conductor.
If you have something specific to reference I'd be glad to consider. I may end up having to run a ground wire if I cannot solve the issue anyhow, but it would appear to be an issue with the dw. It was a display model.
 
  #5  
Old 10-06-11, 12:49 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,594
Article 250.114 of the electrical code requires certain equipment to be used on a grounded circuit. Dishwashers are on that list. Plugging them into a GFI protected receptacle in not a means to skirt this requirement.

The NEC also requires the instructions to be followed when something is installed. The instructions will call for a dedicated circuit. It may mean that a subpanel may need to be installed in order to comply.
 
  #6  
Old 10-06-11, 05:24 PM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
pcboss: Thanks again for your input and concern. It has given me pause and I will contact someone who is intimately familiar with NEC and how it applies in this case. I still think I'm ok and the code I was referencing is section D, article 406.3 which allows "exceptions". The article and link I referenced in my last post was written by a NEC advisor. If it were direct wiring there would be no debate but as a plug is used.

The thread and article I was referencing is in regards to exceptions as allowed in the NEC. Click HERE for the exact code reference....

WIRING ALTERNATIVES
FOR "TWO WIRE" (NON GROUNDED)
ELECTRICAL SYSTEMS
I may end up having to run a ground irrespective but the cause for tripping the GFCI will still have to be answered.
 
  #7  
Old 10-06-11, 05:48 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,594
IMO Article 406 would not override the requirements of Article 250.144. The instructions will also call for the wiring to be grounded.
 
  #8  
Old 10-15-11, 08:48 AM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
Originally Posted by pcboss View Post
IMO Article 406 would not override the requirements of Article 250.144. The instructions will also call for the wiring to be grounded.
pcboss, I came across some pertinent articles and got input by others familiar with NEC code and you were right. The dishwasher requires a ground. Article 406 wasn't an exception in this case.

I was able to run a ground to the dishwasher circuit and happy to say all is working well. I think the GFCI was just to sensitive for this setup and why it was tripping. From researching I think it was just the digital controls bleeding some and causing the trip.

Thanks again, Ralph
 
  #9  
Old 10-15-11, 09:20 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,058
Thanks for letting us know how it turned out.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes