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20A GFCB - 120V photocell - 120V/12V transformer - low voltage landscape lights

20A GFCB - 120V photocell - 120V/12V transformer - low voltage landscape lights

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  #1  
Old 06-23-08, 07:20 PM
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20A GFCB - 120V photocell - 120V/12V transformer - low voltage landscape lights

I finished wiring some low-voltage landscape lights...or so I thought until the ground fault circuit breaker wouldn't stay on.

On a 20A GFCB I have 12/2 running throughout. First to a 120V/12V transformer. The 120 side of the transformer has a black & white wire which leaves me with where to put the ground wire. At the same point I'm tying in a 120V photocell which has a black, white and red wire; I went ahead and connected the red and black to the black line. Again I'm left with where to connect the ground. At the 12V side of the transformer I have two reds so I connected the lights...black to red and white to the other red. I now have three loose ground wires around the transformer so I connected all together and the one loose ground wire left at the end of the photocell got put on a ground screw.

Obviously, I'm all messed up. Please help
 
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Old 06-23-08, 07:28 PM
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You need to connect the black on the photocell to the 120 volt hot leg coming to the transformer and then connect the red to the transformer input. (Check your instructions but the red is usually the switch leg).
Tie the whites together.
There should be a lug to terminate the grounds in the xformer.
If you have to, splice them together and take a pigtail to the ground lug.
Some photcells may cause the GFI to trip.
If this happens, you will need to install a cube relay to alleviate the problem.
 
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Old 06-23-08, 07:50 PM
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I appreciate the quick reply once again dezwit. I have the black on the photocell going to the 120V black input on the transformer. I'm not quite following you on where to connect the red photocell wire..transormer input being the black also or white wire? There's no ground lug on the transformer so do I need a different transformer or is there an alternative? You mention that some photocells may trip the GFI - is that a periodic thing or could it happen from the time of install?
 
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Old 06-23-08, 08:11 PM
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The black coming from the panel connects to the black on the photocell, the red from the photocell connects to the black in the transformer, and the white from the panel connects to the white on the photocell and the transformer white.
 
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Old 06-23-08, 09:08 PM
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I tried that and still no luck. I took the photocell off the circuit and still no luck - the breaker won't flip on. At the end of the circuit, after the last light, I don't have the ground wire terminated...could that be my problem? If so, I take it that I need to stake a grounding rod? Sorry if this seems trivial.
 
  #6  
Old 06-24-08, 07:20 PM
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You need to investigate your GFI circuit/device.
Driving a ground rod can potentially cause more problems than it could ever correct.
If I understand correctly, the GFI is not functioning at the moment.
Are you sure that there is power to the receptacle?
A GFI won't reset if there isn't any power.
You mention the end of the circuit. Is this the last light? From what I read, it seems that there is wire hanging loose?
What are you using to wire these low voltage lights.
Low voltage lighting cable is only two wire.
 
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Old 06-24-08, 09:11 PM
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I'm using 12/2 AWG for everything. There's now a 3 wire push in connector after the last light. No loose wires. Each light connects with two ends of a clamp (my best description) that pierce the wiring sheath.

So I think I last told you that I removed the photocell and still couldn't get the GFCB to turn on. The next thing I tried was using a regular breaker to aid me in troubleshooting. I have two sets of lights...the first set lit up. I took of for the store to pick up a low voltage non contact volt detector and about a minute into checking my wires the first set of lights began turning off for a minute...then back on for a minute. Still inconclusive whether or not there's voltage at the wire in front of my second set of lights...still getting familiar with the volt detector and was running out of light. After I made it back in the house I noticed that the transformer was extremely hot. The transformer wires are only 20AWG and I'm wondering if that is playing a part.
 
  #8  
Old 06-25-08, 08:51 PM
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You need to replace the 12/2 with some low voltage cable that is listed for the purpose that you are using it for. Regular low voltage cable for landscape is the best choice. I'm betting to are creating a short by using the crimp on connectors which is why your lights are turning off and on. It is also why your transformer is getting hot. (or you just have too many lights for the transformer) It is over heating and tripping the internal thermal protection. Do that and I think your problem will be solved. Once you have that figured out, install the GFCB and install the photo cell the way Dezwit described.
 
  #9  
Old 06-26-08, 05:23 AM
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The Insulation Displacement Connectors (IDC) that came with your LV lights weren't designed for Romex. They may fit over the cable, but it doesn't mean they're making contact with the correct conductors.
 
 

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