Equipment Grounds on Bus bar

[brian_mller]

I am a private construction consultant, quality control inspector .

Are more than two equipment grounds allowed to be installed under the same bus bar terminal screws?

 

[Dennis Alwon]

In most cases the panels are rated for 2 conductors per terminal however you cannot have a neutral (grounded conductor) doubled or a neutral and an equipment grounding conductor together as shown

408.41 Grounded Conductor Terminations. Each grounded
conductor shall terminate within the panelboard in an individual
terminal that is not also used for another conductor.
Exception: Grounded conductors of circuits with parallel conductors
shall be permitted to terminate in a single terminal if the terminal is
identified for connection of more than one conductor.

 

[brian_mller]

thanks, thought so!

At first glance when looking at the panel, I thought it was a neutral but it is an equipment ground that is installed. This photo is deceiving !!

 

[kwired]

NEC doesn't permit multiple "grounded" conductors in the same lug - unless they are part of a parallel conductor set where allowed - usually applies to the service or feeder in most instances.

But I have seen some bars of that sort of design that if you looked at the termination data are rated for three conductors.

Look at the labels inside the panel or on the cover it will tell you what you can put in those lugs.

 

[Sierrasparky]

thanks, thought so!

At first glance when looking at the panel, I thought it was a neutral but it is an equipment ground that is installed. This photo is deceiving !!

How is this deceiving?
It is a white conductor yes?
If so it cannot be white if it is a grounding conductor this small.
If it is a grounded conductor then it needs to land on the neutral buss bar.

 

[Knuckle Dragger]

"If it is a grounded conductor then it needs to land on the neutral buss bar."

Is that true even in the Main Breaker Panel? example adding a grounding bar for more flexibility and then someone comes along terminating a neutral under one the the grounding bar terminals.

 

[Sierrasparky]

"If it is a grounded conductor then it needs to land on the neutral buss bar."

Is that true even in the Main Breaker Panel? example adding a grounding bar for more flexibility and then someone comes along terminating a neutral under one the the grounding bar terminals.

Probably not if it is in fact the Main service panel with main breaker and branch and also a bonded. Adding a neutral bar by just securing it to the metal of the box does not make a neutral bar. You need to have it wired to the neutral as you could have a high impedance connection and I don't know the current capacity of a 10-32 screw or sheet metal screw for that matter.

If it is a sub panel with isolated neutral bar then no.

 

[Daniel malack]

In most cases the panels are rated for 2 conductors per terminal however you cannot have a neutral (grounded conductor) doubled or a neutral and an equipment grounding conductor together as shown

In most Northern Virginia counties, they won't let you mix different sizes of wire either. Makes sense to me on solid conductors because the possibility of the smaller conductor could be loose, I don't think stranded would be a problem but they don't let you mix sizes.

Sent from my SM-T350 using Tapatalk

 

[kwired]

Probably not if it is in fact the Main service panel with main breaker and branch and also a bonded. Adding a neutral bar by just securing it to the metal of the box does not make a neutral bar. You need to have it wired to the neutral as you could have a high impedance connection and I don't know the current capacity of a 10-32 screw or sheet metal screw for that matter.

If it is a sub panel with isolated neutral bar then no.

The grounded conductor can not rely on the cabinet for continuity, see 200.2(B), the EGC can.

Square D ground bars use 8-32 screws to attach to the cabinet in general.

 

[kwired]

In most Northern Virginia counties, they won't let you mix different sizes of wire either. Makes sense to me on solid conductors because the possibility of the smaller conductor could be loose, I don't think stranded would be a problem but they don't let you mix sizes.

Sent from my SM-T350 using Tapatalk

Most instructions usually say "2-#14 or 2-#12" or something similae that usually indicates they must be same size. If it says "2- #14-12" then you probably can mix them, per manufacturers intentions.

 

[Smart $]

"If it is a grounded conductor then it needs to land on the neutral buss bar."

Is that true even in the Main Breaker Panel? example adding a grounding bar for more flexibility and then someone comes along terminating a neutral under one the the grounding bar terminals.

Much to the chagrin of many, always (provided the neutral is the grounded conductor... which isn't always true). The electrical demarcation is the Main Bonding Jumper. Grounded conductors to the supply side. Grounding conductors to the other side.

 

[kwired]

Much to the chagrin of many, always (provided the neutral is the grounded conductor... which isn't always true). The electrical demarcation is the Main Bonding Jumper. Grounded conductors to the supply side. Grounding conductors to the other side.

Still works that way when grounded conductor is not a neutral though.

 

[nec_addicted]

Equipment Grounds on Bus Bar

Equipment Grounds on Bus Bar

NFPA 70 NEC 2014 Handbook , 250-32 Exception and Exhibit 250-18. There are so many exceptions throughout..... without showing both ends of the circuit.

 

[Knuckle Dragger]

Probably not if it is in fact the Main service panel with main breaker and branch and also a bonded. Adding a neutral bar by just securing it to the metal of the box does not make a neutral bar. You need to have it wired to the neutral as you could have a high impedance connection and I don't know the current capacity of a 10-32 screw or sheet metal screw for that matter.

If it is a sub panel with isolated neutral bar then no.

I agree with everything you said, I just wanted to throw it out there.
Thanks.