Backstabbing Receptacles

jmellc

Senior Member
Location
Durham, NC
Occupation
Facility Maintenance Tech. Licensed Electrician
I’ve argued that for years. Very poor connections. Sometimes works ok for light loads in houses with no vibration but nothing consistent. Screws are better, pigtailing is best. I pigtail.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
I’ve argued that for years. Very poor connections. Sometimes works ok for light loads in houses with no vibration but nothing consistent. Screws are better, pigtailing is best. I pigtail.


Screws are a cold weld, with astronomical surface area.


All it takes is the slightest resistance in any splice or connection and a run away effect will take place where heating will cause series R to go up, causing more heating, more R even more heating to the point the connection is visibly glowing.
 

jmellc

Senior Member
Location
Durham, NC
Occupation
Facility Maintenance Tech. Licensed Electrician
Screws are a cold weld, with astronomical surface area.


All it takes is the slightest resistance in any splice or connection and a run away effect will take place where heating will cause series R to go up, causing more heating, more R even more heating to the point the connection is visibly glowing.
So you are saying pigtailing is not good? I have had virtually zero issues from pigtailing. I have seen some receptacles burn from screw connections if circuit is heavily loaded. Connection is good but a geavy load on one device is a heavy load on all others up line of it. Pigtailing insures that each device only carries its own load.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Can we just agree that electricians shouldn't be calling receptacles, plugs?

IMO pigtailing is the best method. The EGC must be pigtailed and cannot be back stabbed for a reason.
 

mhanson

Member
Location
Redwood City, CA
Occupation
General Journeyman Electrician
IMO pigtailing is the best method. The EGC must be pigtailed and cannot be back stabbed for a reason.
I didn't realize that EGC must be pigtailed. that being the case why are we allowed to not pigtail HOT and NEUTRAL? IMO this should be the standard. I do a lot of troubleshooting and "back stabbed" connections on a receptacle are the cause of many problems.
mh
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
So you are saying pigtailing is not good? I have had virtually zero issues from pigtailing. I have seen some receptacles burn from screw connections if circuit is heavily loaded. Connection is good but a geavy load on one device is a heavy load on all others up line of it. Pigtailing insures that each device only carries its own load.


Pigtailing when done correctly is also a cold weld. No issue there.

Imo The real risk of loading circuits past 310.16 and 240.4 D is that it stresses the connections. But that comes from violating code.
 

mbrooke

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Location
United States
Occupation
Technician
I didn't realize that EGC must be pigtailed. that being the case why are we allowed to not pigtail HOT and NEUTRAL? IMO this should be the standard. I do a lot of troubleshooting and "back stabbed" connections on a receptacle are the cause of many problems.
mh


I think it comes from code not wanted the EGC path broken if a device is removed.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Can we just agree that electricians shouldn't be calling receptacles, plugs?

IMO pigtailing is the best method. The EGC must be pigtailed and cannot be back stabbed for a reason.
But the reason has nothing to do with safety and everything to do with paranoia. The reason you are required to pigtail EGC's is so that if you remove the device you won't open the EGC connection to the next device. backstabbed connections are every bit as safe as any other kind of connection if it is done correctly. You can make any kind of connection unsafe if you don't do it correctly. The problem with backstab connections is there are a multitude of ways to make it up poorly.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
But the reason has nothing to do with safety and everything to do with paranoia. The reason you are required to pigtail EGC's is so that if you remove the device you won't open the EGC connection to the next device. backstabbed connections are every bit as safe as any other kind of connection if it is done correctly. You can make any kind of connection unsafe if you don't do it correctly. The problem with backstab connections is there are a multitude of ways to make it up poorly.
If you remove the device that is back stabbed in the middle of the run the rest of the circuit is dead anyway so having the EGC still connected isn't doing much. I do agree that there are reasons why the EGC must be pigtailed but I disagree that backstabbing is a good practice.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
If you remove the device that is back stabbed in the middle of the run the rest of the circuit is dead anyway so having the EGC still connected isn't doing much. I do agree that there are reasons why the EGC must be pigtailed but I disagree that backstabbing is a good practice.
I'm inclined to agree that pigtailing EGCs has more to do with paranoia than reality.

Backstabbing gets a bad rap because it can be done poorly in a number of ways and often is. One of the problems is that it's not a good thing to do in a box that's not very deep because the wires get shoved up against the back of the box and can be moved around when the devices put in place. I've also seen people try and use it with stranded wire which is just a terrible idea or with conductors that have not been stripped to the proper length. What you are calling the back stab is just a terminal that is spring loaded. Spring loaded terminals have been around for a long time and by and large they are as safe as screw-in terminals if handled properly. Personally I don't like wrapping stranded wires around a screw and then tightening the screw down. There's plenty of potential for messing that up too.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I'm inclined to agree that pigtailing EGCs has more to do with paranoia than reality.
And to my point about there only being one ground screw on the device is that if there were a place to land more than one EGC installers would do it instead of pigtailing even with pigtailing being required.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
But the reason has nothing to do with safety and everything to do with paranoia. The reason you are required to pigtail EGC's is so that if you remove the device you won't open the EGC connection to the next device. backstabbed connections are every bit as safe as any other kind of connection if it is done correctly. You can make any kind of connection unsafe if you don't do it correctly. The problem with backstab connections is there are a multitude of ways to make it up poorly.

Have you ever opened up a back stab receptacle?
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
I'm inclined to agree that pigtailing EGCs has more to do with paranoia than reality.

Backstabbing gets a bad rap because it can be done poorly in a number of ways and often is. One of the problems is that it's not a good thing to do in a box that's not very deep because the wires get shoved up against the back of the box and can be moved around when the devices put in place. I've also seen people try and use it with stranded wire which is just a terrible idea or with conductors that have not been stripped to the proper length. What you are calling the back stab is just a terminal that is spring loaded. Spring loaded terminals have been around for a long time and by and large they are as safe as screw-in terminals if handled properly. Personally I don't like wrapping stranded wires around a screw and then tightening the screw down. There's plenty of potential for messing that up too.

I disagree, I think the NFPA has slowly started to "wake up" realizing just how important an EGC is, and its integrity.

The surface area in a back stab is not the same as in a screw terminal, let alone that the wire can actually move around slightly as the metal expands and contracts breaking the cold weld.
 

kwired

Electron manager
Location
NE Nebraska
If you remove the device that is back stabbed in the middle of the run the rest of the circuit is dead anyway so having the EGC still connected isn't doing much. I do agree that there are reasons why the EGC must be pigtailed but I disagree that backstabbing is a good practice.
Used to be and I'm sure still is code section that states something to the effect that continuity of the EGC can not rely on the installation of a device.

Take a non metallic wiring method with multiple branch circuits installed but a single EGC. If you interrupted EGC by removing the first device you lost the EGC to all downstream components even if the circuit to that first device was all you turned off.

You can occasionally find old grounding type receptacles that had two grounding screws, I think even into late 1960's installs I have found these. Guessing the rule came about mid to late 1960's though because installs newer than that never seem to have such receptacles.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Used to be and I'm sure still is code section that states something to the effect that continuity of the EGC can not rely on the installation of a device.

Take a non metallic wiring method with multiple branch circuits installed but a single EGC. If you interrupted EGC by removing the first device you lost the EGC to all downstream components even if the circuit to that first device was all you turned off.

You can occasionally find old grounding type receptacles that had two grounding screws, I think even into late 1960's installs I have found these. Guessing the rule came about mid to late 1960's though because installs newer than that never seem to have such receptacles.

Do you have a pic of these dual ground receptacles?
 

kwired

Electron manager
Location
NE Nebraska
Do you have a pic of these dual ground receptacles?
Sorry don't think I do. Seemed to be common to find them if still original installed device on old NM cable with reduced size EGC.

Second EGC screw generally was on opposite side of the yoke from the first one.
 
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