Bonding and grounding

[kevreh]

As a general rule, the ground conductor should be the same size as the current-carrying conductors, and is typically determined by circuit current. For a 15 Amp circuit, one would use #14, w/ a #14 ground.

Definitely do not confuse the electrical ground with the bonding of the equipotential grid.

I understand the difference between grounding and bonding. But tell me this...on my setup my main pump, booster pump, heater have a copper wire connecting all them on the outside, THEN the copper wire is connected to the ground in my subpanel. So, it sounds like my equipment is GROUNDED, but not bonded? In each piece of equipment the internal ground and external screw connector are both connected to the metal frame/case.

 

[kevreh]

Re: Light Junction Box Grounding / Bonding Confusion

Leave them connected.

NEC 680-23 (B)(2)(b) requires nonmetallic conduit to have a bonding wire connected to the ground terminal in the junction box.
NEC 680-24 (F) requires that all metal parts, including grounding terminals, of a wet niche junction box must be connected to panel ground.

Jason,

So, the bonding grid AND the grounded equipment all hooks up to the panel ground?

 

[Bama Rambler]

Re: What size ground wire for wet light niche

It's bonded by virtue of each piece of equipment connected to the same wire. Bonding and grounding have different jobs but the bonding grid can be grounded. It's just not required by the NEC. Your local codes can require it however.

 

[JasonLion]

Re: Light Junction Box Grounding / Bonding Confusion

kevreh, no not always. They are not required to be connected, except "incidentally", and the situations which require those incidental connections don't always occur. While you are allowed to connect them, that used to be discouraged, for good reasons. Now it is left up in the air because connecting them is more or less unavoidable in several common situations. However, interconnections between bonding and ground can cause problems, especially if you connect them in too many different places (which creates ground loops), so connections are normally limited to the ones that are required by code (high voltage light junction boxes and non-double insulated pumps).

If that doesn't confuse you, read it again The rules are messy because they are driven by several different motivations: history, safety, and practicality, which have a habit of conflicting with each other. Connecting bonding and ground is an especially complex issue. The rules about it have changed over the years and a few places still use the older rules.

 

[kevreh]

Re: Light Junction Box Grounding / Bonding Confusion

kevreh, no not always. They are not required to be connected, except "incidentally", and the situations which require those incidental connections don't always occur. While you are allowed to connect them, that used to be discouraged, for good reasons. Now it is left up in the air because connecting them is more or less unavoidable in several common situations. However, interconnections between bonding and ground can cause problems, especially if you connect them in too many different places (which creates ground loops), so connections are normally limited to the ones that are required by code (high voltage light junction boxes and non-double insulated pumps).

If that doesn't confuse you, read it again The rules are messy because they are driven by several different motivations: history, safety, and practicality, which have a habit of conflicting with each other. Connecting bonding and ground is an especially complex issue. The rules about it have changed over the years and a few places still use the older rules.

Well........ Im updating my equipment. There IS NOT a bonding wire back to the pool slab/shell. However the previous electrician connected the equipment bond lugs together then tied them to the ground in the subpanel. So, should I disconnect the coonection to the subpanel (keeping in mind all equip still has the standard ground wire)? Or keep it connected thinking the previous electrician knows better. At this point the equip lugs connected to the panel is redundant since the lug is part of the equip shell like the ground screw. Arghhhghghg.....!!!!

 

[JasonLion]

It is always good to check local code for exceptions/changes. Assuming your code is fairly standard, I would disconnect the bonding wire from the panel and see if you can find a way to connect it to the rebar in the concrete. The chances are fairly good that there was a bonding wire attached to the rebar when the concrete was poured (though you can't count on that). If it is there somewhere and you can find it, then the equipment bonding wire should be connected to it.

 

[kevreh]

It is always good to check local code for exceptions/changes. Assuming your code is fairly standard, I would disconnect the bonding wire from the panel and see if you can find a way to connect it to the rebar in the concrete. The chances are fairly good that there was a bonding wire attached to the rebar when the concrete was poured (though you can't count on that). If it is there somewhere and you can find it, then the equipment bonding wire should be connected to it.

Yeah I remember looking for it in the past and no dice.