Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 17 of 17

Thread: Niche Grounding Headache

  1. Back To Top    #1

    Join Date
    May 2016
    Location
    Burlington, Vermont
    Posts
    19

    Lightbulb Niche Grounding Headache

    Hey folks, I'm dealing with an electrical issue and could use some assistance.

    Background: My pool has a niche installed and previously had a light. The old owner drained the pool and stopped maintaining it. Part of this, for whatever reason, was to cut the power cable attached to the light, pull it back into the conduit and plug up the conduit hole in the niche. He left the cable wired to the panel. He re-installed the light after cutting the cable, but he used a wood screw that was a larger thread than the pilot screw.

    I have managed to install a new light and run its cable up the conduit and wire it into the panel.

    I used a brass pilot screw and it's grabbing some kind of thread because it holds the light in place, but I don't think it's grounding to the niche properly because the circuit trips every time I turn the pool light on.

    I know the circuit is good because a receptacle is on the same circuit and it works perfectly, as long as the pool light isn't turned on.

    From what I can tell, the niche doesn't have a brass or bronze grounding ring between the niche and the face plate. I think the ground is built into the niche and housed in plastic, but I'm not certain.

    Is there some way for me to repair any damage that might have been done by using the wrong screw? Is there a common reason a niche doesn't ground anymore? Where do I go from here?

  2. Back To Top    #2
    Pool Tool's Avatar
    Join Date
    May 2014
    Location
    Western Chicago Area, IL
    Posts
    754

    Re: Niche Grounding Headache

    Hopefully I am following what you are saying. The light niche won't be grounded, but it should be bonded. The light will be grounded to the panel and ultimately the house. There should be a green insulated wire in the new light cable. The screw (assuming this screw holds the trim ring) has nothing to do with the bonding or grounding.

    I would disconnect the cable from the panel until the folks here can understand all that is going on with your light.

    Did you run the new cable through the pool niche conduit up to the panel or j-box without splicing it?
    16' x 32' (21100 gal), vinyl, 1.5 hp Hayward SuperPump,
    Tagelus TA60/60D Sand Filter, Raypak 399K Digital Heater, TF-100

  3. Back To Top    #3
    Zappafan's Avatar
    Join Date
    Aug 2014
    Location
    Hampton, IL.
    Posts
    151

    Re: Niche Grounding Headache

    I would not have anything else on the circuit other than the light. Wire it to it's own breaker. My bad absolutely GFCI breaker.
    17K Gallon,IG Vinyl,1hp Pentair Challenger,Pentair TA60 Sand Filter, Hayward Colorlogic,Re-lined 06-20-15, TF-100,SpeedStir,Lagunitas and Margaritas. Zappafan Pool Build

  4. Back To Top    #4

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,085

    Re: Niche Grounding Headache

    Tricky stuff and I am not a good electrician. I will say that, by far, the most common reason for the breaker to trip is the seal on the fixture is letting in water directly onto the bulb.

    That may not be it b ut it is the most common fault.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  5. Back To Top    #5

    Join Date
    May 2016
    Location
    Burlington, Vermont
    Posts
    19

    Re: Niche Grounding Headache

    Quote Originally Posted by Pool Tool View Post
    Hopefully I am following what you are saying. The light niche won't be grounded, but it should be bonded. The light will be grounded to the panel and ultimately the house. There should be a green insulated wire in the new light cable. The screw (assuming this screw holds the trim ring) has nothing to do with the bonding or grounding.

    I would disconnect the cable from the panel until the folks here can understand all that is going on with your light.

    Did you run the new cable through the pool niche conduit up to the panel or j-box without splicing it?
    Gotcha! I'm a novice electrician, so thanks for bearing with me. I can't see behind the niche, but I assume it is properly bonded. How can I confirm this?

    From the manual for the light: "Use only the special pilot screw provided with this underwater light. This screw mounts and electrically grounds the housing securely to the mounting ring and wet niche. Failure to use the screw provided could create an electrical hazard which could result in death or serious injury to pool users, installers or others due to electrical shock."

    I ran the new cable through the pool niche conduit up to the panel without splicing it and within the cable, there was an insulated green wire. I connected it to the ground bar on the side of the panel.

    The light is new and the seal appears to be intact. No water inside the housing or bulb.

    I'll pick up a new breaker and wire the receptacle separately.

  6. Back To Top    #6

    Join Date
    May 2016
    Location
    Burlington, Vermont
    Posts
    19

    Re: Niche Grounding Headache

    panel.jpg
    The conduit on the left is where the pool light enters the j box. Green insulated to ground bar, white to white and black to black making it inline with the receptacle. The receptacle works - the light trips the breaker.

  7. Back To Top    #7

    Join Date
    Apr 2013
    Location
    Sacramento, CA
    Posts
    2,769

    Re: Niche Grounding Headache

    My short answer is that Dave above is correct, its most likely that your breaker is tripping because of moisture in the fixture. I would pull the fixture and reseal it. Be very careful with placement of the gasket. Inyo pools has some great videos on youtube about changing pool bulbs. And where is the GFCI? If its a 120v light there must be a GFCI on the curcuit. If its a low voltage light there should be a transformer.

    Your question is confused about what is going on here so I offer the following explanation.

    What you should have is a light fixture with a light bulb inside. The fixture has the bulb inside it and a integrated cord out the back that tuns through conduit to a listed junction pox set at least 8 inches above the pool. The fixture is set in the light niche and usually held in place by a retaining ring that is held by a screw on the top of the ring. The light bulb is inside the waterproof fixture. The fixture is made watertight by a lens placed over a gasket.

    Does that all make sense?

    The light fixture itself is not directly grounded but the light bulb and fixture are indirectly grounded by a groundwire in the fixture cord.

    Incidentally there should generally be a bonding jumper. A insulated #8 copper wire running from the niche to the junction box along with the cord.
    22k gallon IG pebblefina, Jandy 1.5 HP VS, Jandy CV Cartridge filter, Fafco solar panels, Polaris 360 supply side cleaner, waterfall

  8. Back To Top    #8
    Pool Tool's Avatar
    Join Date
    May 2014
    Location
    Western Chicago Area, IL
    Posts
    754

    Re: Niche Grounding Headache

    Gotcha! I'm a novice electrician, so thanks for bearing with me. I can't see behind the niche, but I assume it is properly bonded. How can I confirm this? Haha, I myself am a novice and I don't know any way to check for bonding, sorry.

    From the manual for the light: "Use only the special pilot screw provided with this underwater light. This screw mounts and electrically grounds thehousing securely to the mounting ring and wet niche. Failure to use the screw provided could create an electrical hazardwhich could result in death or serious injury to pool users, installers or others due to electrical shock." I am at a total loss with this one, other's will hopefully help out. I don't see that a screw does anything here unless it was a plastic niche with a metal trim ring??

    I ran the new cable through the pool niche conduit up to the panel without splicing it and within the cable, there was an insulated green wire. I connected it to the ground bar on the side of the panel. Sounds great

    The light is new and the seal appears to be intact. No water inside the housing or bulb. This too sounds good

    I'll pick up a new breaker and wire the receptacle separately. Is the existing breaker GFCI protected? Those are required but can be finicky. Hopefully you will have better results once it is wired independently.
    16' x 32' (21100 gal), vinyl, 1.5 hp Hayward SuperPump,
    Tagelus TA60/60D Sand Filter, Raypak 399K Digital Heater, TF-100

  9. Back To Top    #9

    Join Date
    May 2016
    Location
    Burlington, Vermont
    Posts
    19

    Re: Niche Grounding Headache

    Quote Originally Posted by gwegan View Post
    My short answer is that Dave above is correct, its most likely that your breaker is tripping because of moisture in the fixture. I would pull the fixture and reseal it. Be very careful with placement of the gasket. Inyo pools has some great videos on youtube about changing pool bulbs. And where is the GFCI? If its a 120v light there must be a GFCI on the curcuit. If its a low voltage light there should be a transformer.

    What you should have is a light fixture with a light bulb inside. The fixture has the bulb inside it and a integrated cord out the back that tuns through conduit to a listed junction pox set at least 8 inches above the pool. The fixture is set in the light niche and usually held in place by a retaining ring that is held by a screw on the top of the ring. The light bulb is inside the waterproof fixture. The fixture is made watertight by a lens placed over a gasket.

    Does that all make sense?

    The light fixture itself is not directly grounded but the light bulb and fixture are indirectly grounded by a groundwire in the fixture cord.
    The GFCI is on the receptacle, I believe. You can see the circuit breaker on the left in the picture. I think it's a regular breaker.

    What you say makes sense and I'm picking up what you're putting down, but I'm confused about the manual for the light stating: Use only the special pilot screw provided with this underwater light. This screw mounts and electrically grounds the housing securely to the mounting ring and wet niche. Failure to use the screw provided could create an electrical hazard which could result in death or serious injury to pool users, installers or others due to electrical shock.

    The fixture itself doesn't look like it has any water in it. The seal looks intact, no cracks in the lens and I pulled it out of a box, brand new, a few weeks ago.

    Quote Originally Posted by Pool Tool View Post
    "Use only the special pilot screw provided with this underwater light. This screw mounts and electrically grounds thehousing securely to the mounting ring and wet niche. Failure to use the screw provided could create an electrical hazardwhich could result in death or serious injury to pool users, installers or others due to electrical shock." I am at a total loss with this one, other's will hopefully help out. I don't see that a screw does anything here unless it was a plastic niche with a metal trim ring??
    It is a plastic niche. I don't think there's a metal trim ring screwed into it, but I think the plastic is encasing the metal. I'll try to get a picture of the niche underwater, but essentially, the metal is kind of "baked in" with the plastic. That's my assumption from what I've seen.

  10. Back To Top    #10

    Join Date
    Apr 2013
    Location
    Sacramento, CA
    Posts
    2,769

    Re: Niche Grounding Headache

    We cross posted. I didn't see your picture until just now.

    This is not the junction box. This is a sub panel. The cord from the light fixture runs through the conduit to a junction box. A small electrical box often near the pool and about 8 or more inches above ground and then to the subpanel. So look around there is a junction box somewhere where the cord terminates. That is also a source of problems occasionally.

    If the conduit on the left runs to your light then there is no GFCI protection. That's ok if its low voltage and there is a transformer. Its not ok if its a 120 vac light.

    What light do you have?

    And what is that with the pump with GFCI protection on only one leg of the 220?

    - - - Updated - - -

    Did you splice the cord to the light fixture?
    22k gallon IG pebblefina, Jandy 1.5 HP VS, Jandy CV Cartridge filter, Fafco solar panels, Polaris 360 supply side cleaner, waterfall

  11. Back To Top    #11

    Join Date
    May 2016
    Location
    Burlington, Vermont
    Posts
    19

    Re: Niche Grounding Headache

    Quote Originally Posted by gwegan View Post
    We cross posted. I didn't see your picture until just now.

    This is not the junction box. This is a sub panel. The cord from the light fixture runs through the conduit to a junction box. A small electrical box often near the pool and about 8 or more inches above ground and then to the subpanel. So look around there is a junction box somewhere where the cord terminates. That is also a source of problems occasionally.

    If the conduit on the left runs to your light then there is no GFCI protection. That's ok if its low voltage and there is a transformer. Its not ok if its a 120 vac light.

    What light do you have?

    And what is that with the pump with GFCI protection on only one leg of the 220?
    This sub panel is about a foot off the ground and the cord goes straight there. The pool is about 6 - 8 feet to the left in that picture.

    The GFCI protection is because the light is daisy-chained on the same line as a GFCI receptacle. See the orange caps where white and black are twisted to other white and black cables? They exit the panel to a GFCI receptacle.

    I have a Pentair 78438100 light. 12 volt, 300 watt shown here: Amazon.com : Pentair Amerlite 12 Volt 300 Watt Underwater Swimming Pool Light - 50ft. Cord : Swimming Pool Lighting Products : Patio, Lawn Garden

    Not sure what's wired with the pump for GFCI... it's possible something else was wired there, at the time. I'll get a better picture a few steps back and post it here. Stand by...

    And while I am brave, I am not foolish enough to splice the cord to the light fixture. That's how novices wind up in the hospital, I imagine.

  12. Back To Top    #12

    Join Date
    May 2016
    Location
    Burlington, Vermont
    Posts
    19

    Re: Niche Grounding Headache

    panel2.jpg
    The red is the light and GFCI receptacle. 1 is the receptacle, 2 is the switch for the light.
    Blue is the pump. 3 is the switch for the pump and 4 does nothing.

    I'm not too worried about the pump and the blank switch, for now, but there they are, in case it matters.

    EDIT: Sorry the text is so small in the picture! Going from left to right with the switches, we have:

    1) GFCI receptacle wired inline with the pool light
    2) The switch for the pool light
    3) The switch for the pump
    4) A phantom switch that does nothing

  13. Back To Top    #13

    Join Date
    Apr 2013
    Location
    Sacramento, CA
    Posts
    2,769

    Re: Niche Grounding Headache

    If its a 12 volt light where is the transformer? So I'm confused. Also if its a 12 volt light the code does not require a GFCI, a GFCI won't work if there were a problem with the light and GFCI's sometimes false trip with downstream transformers.

    That piolt screw "grounds" the brass ring to the fixture housing which is grounded through the fixture. It would be best if you ordered a replacement screw from Pentair, though I'm not sure one would fit.

    This would have nothing to do with your light not working except it may be screwing up the gasket seal and allowing water in..

    Where does the cord terminate, it does not appear to terminate at the subpanel.
    22k gallon IG pebblefina, Jandy 1.5 HP VS, Jandy CV Cartridge filter, Fafco solar panels, Polaris 360 supply side cleaner, waterfall

  14. Back To Top    #14

    Join Date
    May 2016
    Location
    Burlington, Vermont
    Posts
    19

    Re: Niche Grounding Headache

    Quote Originally Posted by gwegan View Post
    If its a 12 volt light where is the transformer? So I'm confused. Also if its a 12 volt light the code does not require a GFCI, a GFCI won't work if there were a problem with the light and GFCI's sometimes false trip with downstream transformers.

    That piolt screw "grounds" the brass ring to the fixture housing which is grounded through the fixture. It would be best if you ordered a replacement screw from Pentair, though I'm not sure one would fit.

    This would have nothing to do with your light not working except it may be screwing up the gasket seal and allowing water in..

    Where does the cord terminate, it does not appear to terminate at the subpanel.
    I am almost too ashamed to admit this, but it looks like I bought the wrong light. The previous light was 120 volt. I've contacted the reseller to see if they will allow an exchange or refund, but I'm not holding my breath. Would it be better to buy a 120 volt light or should I install a transformer and stick with the current light?

    If I weren't so ashamed, I'd be irate!

  15. Back To Top    #15
    Pool Tool's Avatar
    Join Date
    May 2014
    Location
    Western Chicago Area, IL
    Posts
    754

    Re: Niche Grounding Headache

    Don't feel bad, with the plethora of options and different setups it happens.

    16' x 32' (21100 gal), vinyl, 1.5 hp Hayward SuperPump,
    Tagelus TA60/60D Sand Filter, Raypak 399K Digital Heater, TF-100

  16. Back To Top    #16

    Join Date
    Apr 2013
    Location
    Sacramento, CA
    Posts
    2,769

    Re: Niche Grounding Headache

    I assure you are neither the first or the last.

    The world is most likely going towards low voltage

    Somewhere on here I have a post that explains the differences.
    22k gallon IG pebblefina, Jandy 1.5 HP VS, Jandy CV Cartridge filter, Fafco solar panels, Polaris 360 supply side cleaner, waterfall

  17. Back To Top    #17

    In the Industry

    Join Date
    Jan 2012
    Posts
    340

    Re: Niche Grounding Headache

    I would not reuse the 12V fixture after 120V has been applied. At the very least, you will have to replace the bulb and gasket. Unfortunately, you have no way of knowing what kind of damage you may have caused the fixture.

    Make the decision either way and go with new equipment, IMO.
    25K aggregate IG, Intellipro, FNS48, Polaris 360, PG2000 fiber optic light source

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •