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 01-17-2011, 05:14 AM   #1
Member
 
Join Date: Feb 2010
Location: Oklahoma
Posts: 978
Rewards Points: 500
Default

GFCI confusion


Numerous posts here indicate that on (older) circuits which do not have a bonding conductor present it is permissible to replace an older 2-prong receptacle with a GFCI receptacle. One of the more heavily emphasized prerequisites for this allowance is to place the provided sticker at the receptacle which indicates 'no equipment ground'.

What is the purpose of this sticker? Do GFCIs without a bonding conductor operate differently than those with a bonding conductor?


Last edited by jlmran; 01-17-2011 at 06:13 AM.
jlmran is offline   Reply With Quote
Old 01-17-2011, 06:26 AM   #2
Member
 
Join Date: Mar 2007
Location: Eighty Four, Pa.15330
Posts: 1,334
Rewards Points: 666
Default

GFCI confusion


Try this. If you are operating an appliance,say refridgerator on a gfi 2 wire non grounded circuit and the compressor is leaking to the frame,the whole unit is hot. I've seen where a mom had opened the fridge while doing dishes.She got zinged,but was ok.The device operated as designed,I got asked to restock her freezer.

bobelectric is online now   Reply With Quote
Old 01-17-2011, 08:00 AM   #3
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,968
Rewards Points: 2,032
Default

GFCI confusion


The GFCI unit works the same way.

1. If there is a ground prong hole in the receptacle that is not grounded, it must be labeled so. (Many situations such as simply substituting a 3 prong receptacle where a 2 prong receptacle used to be in an ordinary circuit are not allowed at all.)

2. The GFCI is intended to protect people from electrocution but there are a few more situations where you could get a slight shock if there is no ground.

3. Users of electronic equipment are warned that if certain hum or other undesirable situations normally alleviated by a common equiment ground are encountered, that the receptacle is not providing such a ground and external grounding such as a separate wire daisy chained among the equipment could be desirable.
__________________
Forget super sized fries. The Washington Redskins could promote healthy eating with First Lady Obama by choosing a (red skinned) turnip for a mascot.

Last edited by AllanJ; 01-17-2011 at 09:44 AM.
AllanJ is offline   Reply With Quote
Old 01-17-2011, 08:55 AM   #4
Member
 
Join Date: Dec 2010
Location: NY
Posts: 66
Rewards Points: 75
Default

GFCI confusion


A GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one-thirtieth of a second.

Bonding ( that most people call a ground, or ground wire) the appliance gives a third path for fault current to return back to the source of supply.

Proper bonding creates an electrically continuous low resistance path for fault current to return to the neutral at the service.

Say the frost builds up in the back of your refrigerator. A relay get frozen up and there is 2 or 3 amps of fault current to the refrigerator frame.

2 or 3 amps is not enough current to trip your 15 amp breaker.
Without a return ( bonging ground wire) the refrigerator is energized.

The GFCI doesn't pop because there isn't any current flow or imbalance (no bonding) / ground wire.

When you grab on to the reefer and touch the wet counter top or dish water the current flows. YOU! become the lower resistance path back to the source. The GFCI detects the current imbalance and trips.

Hope this helps,
Bob
Hourglass52 is offline   Reply With Quote
Old 01-17-2011, 09:04 AM   #5
Member
 
Join Date: Feb 2010
Location: Oklahoma
Posts: 978
Rewards Points: 500
Default

GFCI confusion


I understand how GFCIs function. My original question addressed the need for the sticker. What decisions would a user make based on the 'no ground' label?
jlmran is offline   Reply With Quote
Old 01-17-2011, 09:44 AM   #6
Member
 
Join Date: Dec 2010
Location: NY
Posts: 66
Rewards Points: 75
Default

GFCI confusion


Quote:
Originally Posted by jlmran View Post
I understand how GFCIs function. My original question addressed the need for the sticker. What decisions would a user make based on the 'no ground' label?

Basically the sticker is telling the user that they will not be protected in a ground fault conditions. No bonding = no ground.

The GFCI will protect you at a lower over current condition. If you drop your laptop in the bath tub while taking a bath it will trip quicker than a OCPD.



Bob
Hourglass52 is offline   Reply With Quote
Old 01-17-2011, 09:46 AM   #7
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,968
Rewards Points: 2,032
Default

GFCI confusion


Quote:
Originally Posted by jlmran View Post
I understand how GFCIs function. My original question addressed the need for the sticker. What decisions would a user make based on the 'no ground' label?
Perhaps use a different receptacle. Or perhaps not if he needs an extension cord.
__________________
Forget super sized fries. The Washington Redskins could promote healthy eating with First Lady Obama by choosing a (red skinned) turnip for a mascot.
AllanJ is offline   Reply With Quote
Old 01-17-2011, 09:58 AM   #8
Member
 
Join Date: Oct 2009
Posts: 847
Rewards Points: 614
Default

GFCI confusion


The purpose of the sticker is (obviously) to tell the user that a ground wire is not present. Safety is not affected. Some devices like surge protectors need to ground to dump excess voltage. When hooked up to a non-grounded GFCI, electronics will not have over-voltage protection.

In other cases, electronics may have interference or noise.

Human safety is not jepordized
Anti-wingnut is offline   Reply With Quote
Old 01-17-2011, 10:05 AM   #9
Member
 
Join Date: Feb 2010
Location: Oklahoma
Posts: 978
Rewards Points: 500
Default

GFCI confusion


Electronics is the answer. Thanks.

"Anti-wingnut" - does that mean you crimp or solder all connections?
jlmran is offline   Reply With Quote
Old 01-17-2011, 10:15 AM   #10
Member
 
Join Date: Oct 2009
Posts: 847
Rewards Points: 614
Default

GFCI confusion


Quote:
Originally Posted by jlmran View Post
"Anti-wingnut" - does that mean you crimp or solder all connections?
No, has nothing to do with electricity.

Too bad people couldn't have answered your question earlier. It was clear what you were asking, but people like to drone on about tangential subjects and impress themselves
Anti-wingnut is offline   Reply With Quote
Old 01-17-2011, 10:21 AM   #11
I=E/R
 
a7ecorsair's Avatar
 
Join Date: May 2010
Location: Minnesota
Posts: 2,052
Rewards Points: 1,000
Default

GFCI confusion


Quote:
Originally Posted by jlmran View Post
I understand how GFCIs function. My original question addressed the need for the sticker. What decisions would a user make based on the 'no ground' label?
Most people don't understand what the sticker is telling them. And then, how long will the sticker stay in place? Young people will just insert the plug if it fits.
a7ecorsair is offline   Reply With Quote
Old 01-17-2011, 11:01 AM   #12
Member
 
Join Date: Feb 2010
Location: Oklahoma
Posts: 978
Rewards Points: 500
Default

GFCI confusion


Quote:
Originally Posted by a7ecorsair
Most people don't understand what the sticker is telling them. And then, how long will the sticker stay in place? Young people will just insert the plug if it fits.
Another thread (can't cite it right now) has discussed the lack of training in the industrial arts for the young people as a real problem.

jlmran is offline   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
Freezer tripping GFCI davidclements Appliances 57 08-13-2014 09:14 PM
GFCI confusion Bigplanz Electrical 15 01-18-2010 09:56 PM
Gfci Circuit howard.wheaton Electrical 10 01-29-2009 06:14 PM
GFCI Question Mdbuilder Electrical 6 06-19-2008 04:15 PM
GFCI questions 5circles Electrical 4 11-05-2007 09:24 PM




Top of Page | View New Posts

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