wiring of wet niche in-ground pool light

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  #1  
Old 07-20-13, 09:03 AM
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wiring of wet niche in-ground pool light

I decided to connect the pool light in my in-ground pool that has been disconnected for several years. To check if the light was still operational I connected the three wires (black, white and green) to a 120 volt source. The light worked fine. However, seeing that the ground wire from the niche was not connected I assumed incorrectly that it should be connected to the green wire from the light and as you might expect I ended up blowing a circuit breaker. I pulled the light and found the light housing to be burned through and filled with water. Fortunately I have a discarded light that upon checking by connecting it's three wires to 120 volt seems to work fine. That being the case I thought it wise to check with do it yourself on proper wiring before burning out this unit also. I am assuming the correct wiring is as follows: The single insulated green wire from the wet niche is connected to the green screw in the J box. The three insulated wires from the light are connected thru the J box to the three wires from the remote ground fault unit (green to green, black to black and white to white). An on - off switch is wired between the black wire leaving the ground fault unit and the black wire going to the light thru the J box. Am I correct in my proposed wiring?
Bob
 
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Old 07-20-13, 09:14 AM
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Do you have the lighting unit that uses a replacement bulb ?

It sounds like you do and that is was full of water and worked ???

The niche ground and the lamp ground are both ground and usually get connected together inside the deck junction box. . Connecting the niche ground shouldn't have caused the breaker to trip.
 
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Old 07-20-13, 09:39 AM
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The lighting unit uses a replacement bulb. The light fixture was not filled with water. This occured only after the shorting problem which blew the circuit breaker. You reply confuses me. From information I was able to find on the internet the single green ground wire from the niche is supposed to terminate at the green screw in the J box and not connect to the light ground. This seems right in that the light worked fine when it's three wires were connected to the 120 volt three wires. However, when the niche green ground wire was added to the light green wire and the 120 volt green wire the light burned out, the light housing was burned through and the circuit breaker tripped.
 
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Old 07-20-13, 09:51 AM
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Do you have a brand on the light ..... Hayward perhaps ?

In the Jbox are several ground screws. The niche is on one. The light is on another. There is only one ground source.

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Old 07-20-13, 10:41 AM
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keep in mind these are sealed lights and must be in the water before putting power to them. They will blow out of water.
 
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Old 07-20-13, 03:44 PM
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additional information

After getting your reply I checked closer into my situatio.

Starting at my remote power source I have a ground fault unit wired into a 120 volt source. Leaving the ground fault unit are two wires (one red and one white). An on/off swithch is spliced into the red wire. Both wires go to the J box. Also at the J box are three wires from the light unit (one black, one white and one green) and a single green wire from the niche.

As for wiring at the J box I am assuming that the black and red wires are connected together and the two white wires are connected together. That leaves one green wire from the light unit and one green wire from the niche. Am I right in assuming that these two green wires are connected together using the green screw on the J box?

Checking the volage at the J box I get: 120 volt between red and white wire from the ground fault unit, 120 volt between red wire and green wire from the niche, 0 volts between white wire from the ground fault unit and the green wire from the niche. However, when I connect the white wire from the ground fault unit to the green wire from the niche and check the voltage between these and the red wire from the ground fault unit the ground fault unit trips.
 
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Old 07-20-13, 04:30 PM
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Disconnect the white and black wiring coming from the light. You will need to check for resistance between the white and green and the black and green.

There should be absolutely no measurable resistance between the two lamp power wires and ground. If there is..... you have a water leak and the GFI will trip.
 
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Old 07-22-13, 08:10 AM
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Thank you for your latest reply. I disconnected all three wires from the light which is submerged in the niche and checked resistance between the lights wires: 600 ohms black to green, 600 ohms white to green and black to white 0 omhs. I then disconnected all three wires from the light which is submerged in the niche and checked resistance between the lights wires and the green wire from the niche: 600 ohms black to green, 600 ohms white to green, black to white 0 omhs, and green to green 0 onms. Assuming worst case thereby requiring the purchase of a new light I have a question based on the J box wiring you provided. It shows three power source wires coming from the ground fault unit into the J box. I only have two wires, a white and a red. That being the case in wiring a new light at the J box do I simply connect the two white wires, connect the red and black wires and connect the green wire from the light to the green screw on the J box. Thank again for all you help.
Bob
 
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Old 07-22-13, 08:19 PM
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Since you've measure a resistance to ground....... your fixture has a problem.

That deck box is just a representative picture but you should have a green wire along with your white and red that also connects to the j box.
 
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