Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 02-06-2013, 07:44 PM   #1
Member
 
Join Date: Dec 2010
Location: southeastern mass.
Posts: 168
Rewards Points: 168
Default

gfci question


I was testing a portable gfci cord and found that it would shut off with the test button and reset normally with the reset button. Next I tested it with my gfci outlet tester and it would not shut off. Is the gfci good or bad???

Reading on line it appears that separate outlet testers will not work on a two wire ungrounded system. This is a three wire (grd-blk-wht) set up. The gfci has a 10mA trip current. It appears that most Gfci's are in the 4-6 mA range.

Could it be that the outlet tester is a lower current trip rating than the 10mA and that is why it will not trip the gfci???

bottom line is the pigtail gfci any good?

thanks for any input and thoughts.

bernie

bernie963 is offline   Reply With Quote
Old 02-06-2013, 10:09 PM   #2
Member
 
Join Date: Jan 2012
Location: IL
Posts: 823
Rewards Points: 698
Default

gfci question


Outboard testers operate by sending some current down the ground wire. If the ground isn't connected then such a tester won't work. This doesn't mean the GFCI is faulty, its just the outboard tester can't create a leakage (fault) current without a ground. So it isn't anything to do with how much of a leakage current the outboard simulator makes vs. the internal GFCI test button. Without a ground return the outboard tester leakage is zero mA.

The test button on the GFCI device works differently, it sends a return current back down the neutral but it sends that current return outside of the differential transformer inside the GFCI. This creates a current imbalance which trips the GFCI. This is why the GFCIs test switch can work without a ground line.


Last edited by curiousB; 02-07-2013 at 09:34 AM.
curiousB is online now   Reply With Quote
Old 02-06-2013, 11:12 PM   #3
Licensed Electrician
 
k_buz's Avatar
 
Join Date: Mar 2012
Location: SE Wisconsin
Posts: 4,343
Rewards Points: 2,006
Default

gfci question


According to the specs of every GFI outlet I've installed, the only way to test them is with the "Test" button on the device. I will bet that your GFI cord is the same. If you press the Test button and it trips, you can assume it is working.
__________________
__________________________________________________ ______________
Answers based on the National Electric Code. Always check local amendments.


k_buz is offline   Reply With Quote
Old 02-08-2013, 04:14 AM   #4
Member
 
Join Date: Dec 2010
Location: southeastern mass.
Posts: 168
Rewards Points: 168
Default

gfci question


Thanks guys. Yesterday I spoke with an electrician (co-worker) about gfci testing. He suggested that the older gfci's may and do fail to operate correctly even if the test button works. The newer ones don't fail with age. Older styles have to be exersized monthly or the contacts weld together.

Also different testers do have different mA leakage which is why some gfci;s will not trip on an external test.

His advise, throw it away, better safe than sorry.

On a totally different note: K_buz, you mentioned on another thread about cordless vs corded drills and using extention cords "that they come in different lengths" I am being polite by posting this here. You missed the obvious, "they also come in different colors" HA, HA

bernie
bernie963 is offline   Reply With Quote
Old 02-08-2013, 06:22 AM   #5
Member
 
Join Date: Jan 2012
Location: IL
Posts: 823
Rewards Points: 698
Default

gfci question


Your electrician friend is wrong. This is nothing to do with GFCI sensitivity. I outlined the exact issue two posts prior.
curiousB is online now   Reply With Quote
Old 02-08-2013, 06:52 AM   #6
Member
 
Join Date: Sep 2011
Location: western Ny
Posts: 1,251
Rewards Points: 516
Default

gfci question


GFCI devices do not use a ground wire in the test or fault mode. GFCI devices will/should work fine without a ground present.
danpik is offline   Reply With Quote
Old 02-08-2013, 10:45 AM   #7
Member
 
Join Date: Jan 2012
Location: IL
Posts: 823
Rewards Points: 698
Default

gfci question


Quote:
Originally Posted by danpik View Post
GFCI devices do not use a ground wire in the test or fault mode. GFCI devices will/should work fine without a ground present.
Of course. I outlined this above. An external GFCI tester will not work without a ground.
Attached Thumbnails
gfci question-gfci.jpg  


Last edited by curiousB; 02-08-2013 at 11:04 AM.
curiousB is online now   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
GFCI question regarding hardwired vs plug-in disposal mystic_cobra Electrical 24 04-13-2012 07:26 PM
GFCI outlet and breaker question danette32 Electrical 5 02-11-2012 06:25 PM
GFCI Conduit question llenod Electrical 3 04-06-2011 01:09 PM
GFCI question. Please Help. the banana k1ng Electrical 4 10-09-2009 08:35 PM
GFCI Question Mdbuilder Electrical 6 06-19-2008 04:15 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.