Light niche bond wire

[Motorman931]

Good evening,

I am underway a pool renovation. I need to run a new bond wire from niche to new pool equipment location. A previous installer (perhaps original PB) epoxied over the connection where the wire attaches to the niche. I am hesitant to attempt to break free the epoxy and risk damaging the 30 year old niche.

Is there any issue with using a split bolt bonding lug to connect the old wire to a new bond wire within the niche. New wire will run to the ground bar in the j box.

It seems to me that the niche would be bonded and the water would be bonded as well.

Thanks for your input.

 

[JamesW]

Is there any issue with using a split bolt bonding lug to connect the old wire to a new bond wire within the niche.

I think that that would be acceptable.

Note that any underwater connection might be required to be "encapsulated in, a listed potting compound to protect the connection from the possible deteriorating effect of pool water".

New wire will run to the ground bar in the j box?

Correct.

If you have a 12 volt light, the ground/bond is not required.

The light niche should be bonded from the back of the niche.

The wire inside is a supplemental ground wire.

It is called a "Bonding Jumper", but its purpose is grounding.

A bonding jumper is any wire that connects two points together and it does not necessarily mean that it is part of the bonding grid.

 

[JamesW]

Rust from pool light ground wire

I had new Hayward Pool Light (non LED) installed last year. Shortly after, I noticed a streak of rust stains appearing above the light. The streak is easily cleaned with Vitamin C powder in a sock and being doing that every two - three weeks. I finally removed the light from the Niche to see...

www.troublefreepool.com

 

[JamesW]

Why a low impedance bond from a wet-niche luminaire to its forming shell and pool bonding grid reduces the risk of electric shock.

The equipment grounding conductor in the flexible cord of the wet-niche luminaire may be relatively small (as little as 16 AWG in accordance with the NEC), and may have a length of one hundred feet or more.

The relatively small AWG and long length will result in increased impedance through the flexible cord equipment grounding conductor.

If the electrical bond between the luminaire and the forming shell is poor or absent, in an electrical fault condition within the luminaire this increased flexible cord impedance causes a relatively greater voltage potential between the dead metal of the luminaire and other dead metal connected to the premises’ equipment grounding conductor.

The supplemental equipment grounding conductor in the form of corrosion resistant metallic conduit connected to the forming shell or the 8 AWG copper conductor routed with the flexible cord in nonmetallic conduit provides a second, more conductive, path for fault current originating in the luminaire.

https://www.ul.com/global/documents/offerings/perspectives/regulators/electrical/newsletters/swimpool0803.pdf

 

[JamesW]

The insulated copper equipment grounding conductor required with rigid nonmetallic conduit is terminated at an approved grounding terminal in the junction box (or transformer enclosure) and at the inside terminal of the grounding/bonding terminal on the fixture's forming shell.

This conductor has an equipment grounding function, not a bonding function.

It's in addition to, and of a completely different function than, the No. 8 bonding conductor usually connected to the external bonding lug.

The bonding conductor, which must be solid, connects the forming shell to the common bonding grid, as required by Sec. 680-22(a) and (b).

The No. 8 insulated copper equipment grounding conductor must be stranded, however. (Sec. 310-3 requires all No. 8 and larger conductors in raceway to be stranded.)

The two exceptions given do not apply here.

And it's important to also remember that Sec. 310-12(b) will normally require that the insulation be colored green.

Wiring wet-niche fixtures at the 1996 OLympics Aquatic Center. | Electrical Construction & Maintenance (EC&M) Magazine

 

[Motorman931]

The insulated copper equipment grounding conductor required with rigid nonmetallic conduit is terminated at an approved grounding terminal in the junction box (or transformer enclosure) and at the inside terminal of the grounding/bonding terminal on the fixture's forming shell.

This conductor has an equipment grounding function, not a bonding function.

It's in addition to, and of a completely different function than, the No. 8 bonding conductor usually connected to the external bonding lug.

The bonding conductor, which must be solid, connects the forming shell to the common bonding grid, as required by Sec. 680-22(a) and (b).

The No. 8 insulated copper equipment grounding conductor must be stranded, however. (Sec. 310-3 requires all No. 8 and larger conductors in raceway to be stranded.)

The two exceptions given do not apply here.

And it's important to also remember that Sec. 310-12(b) will normally require that the insulation be colored green.

Wiring wet-niche fixtures at the 1996 OLympics Aquatic Center. | Electrical Construction & Maintenance (EC&M) Magazine

Ok, so if I understand correctly, the “bonding” should be completed already via the back of the niche to the equipotential bonding grid. The insulated green inside the niche is no longer needed since new light is 12 volt ?

 

[JamesW]

(a) Metal Conduit. Metal conduit shall be approved and shall be of brass or other approved corrosion-resistant metal.
(b) Nonmetallic Conduit. Where a nonmetallic conduit is used, an 8 AWG insulated solid or stranded copper bonding jumper shall be installed in this conduit unless a listed low-voltage lighting system not requiring grounding is used. The bonding jumper shall be terminated in the forming shell, junction box or transformer enclosure, or ground-fault circuit-interrupter enclosure. The termination of the 8 AWG bonding jumper in the forming shell shall be covered with, or encapsulated in, a listed potting compound to protect the connection from the possible deteriorating effect of pool water.

 

[JamesW]

As long as the light is a "Listed" 12 volt light that does not require a ground, the supplemental ground/bonding jumper is not required.

The transformer and junction box are also required to be Listed.

See the below thread for a discussion about what a Listed Product is.

UL Listing required?

When replacing a light fixture that is in a wet niche, is the new fixture required to be UL Listed? I'm considering a fixture from sunseeker, but it is not UL. I would really like to go with the SS fixture, but don't want to do something wrong.

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The National Electrical Code (NEC) requires all underwater lighting to be certified to UL 676, the Standard for Underwater Luminaires and Submersible Junction Boxes.

The Standard for transformers is UL379 and it can be “Listed” by any NRTL (Nationally Recognized Testing Laboratory).

 

[JamesW]

680.23 Underwater Luminaires. This section covers all luminaires installed below the normal water level of the pool.

(8) Compliance.

Compliance with these requirements shall be obtained by the use of a listed underwater luminaire and by installation of a listed ground-fault circuit interrupter in the branch circuit or a listed transformer for luminaires operating at not more than 15 volts.

 

[Motorman931]

Perfect. The brochure does show UL and ETL listings.

Thanks for everything!

 

[JamesW]

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[JamesW]

Article 100 of NFPA 70®, National Electrical Code® (NEC®), defines listing as “equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose.”

NFPA Journal, NFPA 70, Spring 2021 | NFPA

Understanding the what, when, and why about NEC listing requirements

www.nfpa.org