Bonding wires: What do I have?

[rickmnj]

Hi again,

I'm in the final stages of wiring as the result of relocating my inground pool equipment.

As some may recall, the original wiring was done to older / outdated code. For instance my 220v filter pump motor was (hard) wired without a ground and off a standard NON-GFCI breaker...this was done through an Intermatic timer. I have since run a separate ground conductor for the motor, also through the Intermatic timer. Also, the circuits run through the PVC conduit are now all GFCI protected.

I also moved the Deck Box by extending the 1/2" brass pipe. Here's where I have questions.

When dissembling the original Deck Box installation I noted a #8 , insulated (green) wire connected to a lug inside the Deck Box. I also noted the ground wires from the two niche lights and convenience outlet attached to a lug on the other end of the box.

Problem is the #8 wire, which fed into the Deck Box through a short piece of PVC conduit, went nowhere. It had been cut. Also noted was a #8, (green) insulated wire (same type of wire as described above) coming out from under the brick pool deck, near the niche light brass conduit, convenience outlet PVC conduit and all PVC feed/return piping. It was also cut and attached to nothing.

So, my questions are:

- Is the wire from under the brick deck from the stainless steel niche light fixture? If so, isn't the brass pipe/conduit supposed to be the bonding vehicle for the light? I believe my niche has a bonding lug accommodation (see pic)

- If not from the light is the wire from under the deck from the bonding grid of the pool structure, metal accessories etc ?

- Could the #8 wire attached to junction box lug (and goes nowhere) be the wire that is to be used to bond the motor case and other metallic equipment?
OR
- Perhaps this wire was once connected to a ground rod (haven't looked for one but thinking it would be obvious). It seems this might be the case since the Lug for this #8 wire and the lug for the equipment grounds are basically (electrically) connected through the brass Deck Box chassis. My understanding is that the Bonding wire and equipment grounds are to be electrically separate as they serve different purposes.

Any thoughts on what I've found?






-

 

[Melt In The Sun]

Not sure about the bonding....sorry.

I know it's not what you asked, but I can see in the last picture that you used DWV (drain, waste, vent) elbows in your plumbing. Those aren't SCH 40 (not rated for high pressure) and I'd recommend replacing them before you bury the pipes.

 

[Bama Rambler]

Chances are that wire coming out of the junction box is supposed to be connected to the niche bonding wire. Also the wire you found coming from under the deck should be connected to the grid somewhere. In the US the bonding and grounding isn't required to be connected, but it's not prohibited from being connected.

 

[rickmnj]

Melt in the Sun: Thanks for the heads up. I didn't realize those weren't Sch 40. I only used 2 or 3. Reason I used was because they have a longer arc and I figured they would be freer flowing.

 

[rickmnj]

Chances are that wire coming out of the junction box is supposed to be connected to the niche bonding wire. Also the wire you found coming from under the deck should be connected to the grid somewhere. In the US the bonding and grounding isn't required to be connected, but it's not prohibited from being connected.

This is where I'm confused. I though the brass conduit from the niche was used instead of a wire.

 

[rickmnj]

Here's the Deck Box after removing the cover...

 

[Bama Rambler]

OK I see it better now. That bare wire should be connected to the bonding loop. And you're right about the conduit being the bonding vehicle.

 

[rickmnj]

Bama, Thanks for the reply. This makes sense, to a degree (in my mind). The two #8 wires appear to be the same exact wire but cut...with ends stripped. I found that interesting. So, it seems logical the wire coming from under the deck connects to the wire you mention.

What still has me concerned is that the bond wire is electrically connected to the equipment ground via the brass chassis of the deck box. Do you or others have a similar setup? Could it be the previous owner cut the wire for this reason?

Also, how would I tie the motor bond lug to this point?

BTW, the pool pump motor is just under 13' from the pool edge, separated by a brick topped concrete deck.

 

[rickmnj]

ADD: I just found a Home Inspector site (nachi.org). One gentleman posted a similar question and the members replied that the connection of the two systems (bonding and equipment ground) is pretty much inevitable at a few different points, including at the deck box for the niche light.

So, can I utilize the extra threaded post in the Deck Box with a Beaver Tail bonding wire connector and run the wire out and over to the pool pump motor? Does the #8 wire have to be uninsulated? Please reference pic.

 

[Bama Rambler]

The bonding wire needs to be bare. However, tying the bond for the pump to the ground post in the box is not the right way to do it. You should buy a bonding splice (split bolt) and tie the pump bond wire directly to the loop.

 

[rickmnj]

Add: Quote: "However, tying the bond for the pump to the ground post in the box is not the right way to do it." I'm not following you here. The pic above shows the addition of an approved bonding lug attached to the deck box exactly like the other bonding lug.

Also, when I read the code it seems to say that the bond wire needs to be bare where it connects the various structures of the grid together, but not to the equipment....

Here is the code section on bonding from the 2008 National Electrical Code:

(B) Bonded Parts. The parts specified in 680.26(B)(1)
through (B)(7) shall be bonded together using solid copper
conductors, insulated covered, or bare, not smaller than
8 AWG or with rigid metal conduit of brass or other identified
corrosion-resistant metal. Connections to bonded
parts shall be made in accordance with 250.8. An 8 AWG or
larger solid copper bonding conductor provided to reduce
voltage gradients in the pool area shall not be required to be
extended or attached to remote panelboards, service equipment,
or electrodes.


(a) Structural Reinforcing Steel. Unencapsulated structural
reinforcing steel shall be bonded together by steel tie
wires or the equivalent. Where structural reinforcing steel is
encapsulated in a nonconductive compound, a copper conductor
grid shall be installed in accordance with
680.26(B)(1)(b).
(b) Copper Conductor Grid. A copper conductor grid
shall be provided and shall comply with (b)(1) through
(b)(4).
(1) Be constructed of minimum 8 AWG bare solid copper
conductors bonded to each other at all points of crossing


(b) Copper Conductor Grid. A copper conductor grid
shall be provided and shall comply with (b)(1) through
(b)(4).
(1) Be constructed of minimum 8 AWG bare solid copper
conductors bonded to each other at all points of crossing

 

[rickmnj]

Update: Considering the advice given I stripped the end of the Bond wire which protruded from under the brick deck and secured two split-bolt "bugs". Wired one bug directly to the Deck Box and wired the second one directly to the pump motor. I did not wire as shown in the picture above.
I'll be adding a third as I will be installing an aluminum estate fence around the pool and will need to bond that as well.