need outdoor lamppost wiring help
#1
08-02-03, 10:37 AM
need outdoor lamppost wiring help
I have a lamppost on my front lawn that is wired using 12-2 with ground and connected directly to its own 20 amp breaker in the breaker panel. The post worked great for a few years and then stopped working, with the light getting dimmer before going out altogether. I replaced the guts of the fixture being that they were all corroded. When I turn the breaker on, it immediately shuts off. I'm hoping to avoid digging up my lawn to replace the wiring. I hope someone can offer some advice. Thank you.
#2
08-02-03, 10:52 AM
Member
First, I hope this is 12/2 UF-B and not 12/2 NM-B. If the latter, then that could explain your problem completely.
Second, I assume that this is GFCI protected, either by a GFCI breaker or a GFCI receptacle. Is this true?
You may in fact need to dig up your lawn, but we will explore other possibilties first. As an experiment, disconnect and separate all wires at the post and see if the breaker will stay on then. If not, the fault is in the underground wiring, and you'll probably need to replace it. If the breaker stays on with the fixture removed, then the problem is likely at your lighting fixture.
Second, I assume that this is GFCI protected, either by a GFCI breaker or a GFCI receptacle. Is this true?
You may in fact need to dig up your lawn, but we will explore other possibilties first. As an experiment, disconnect and separate all wires at the post and see if the breaker will stay on then. If not, the fault is in the underground wiring, and you'll probably need to replace it. If the breaker stays on with the fixture removed, then the problem is likely at your lighting fixture.
#3
08-02-03, 11:04 AM
outdoor lamppost wiring help
Thank you for your quick response. Looks like I am 0 for 2. The wiring is 12-2 NM-B and the circuit breaker is not GCFI. Does this mean the wiring has to be completely replaced? And if so, what do you recommend? Please advise. Thank you.
#5
08-02-03, 07:23 PM
I tried the experiment you suggested and with all wires at the lamppost disconnected the breaker still shuts off. It must be the underground wiring. Please let me know if there is anything else I can try before having to break ground. Thank you for you help.
#6
08-02-03, 07:28 PM
Member
If there are any places to disconnect this wire between the breaker and where the wiring goes into the ground, you might try that as another experiment.
But you better start digging. And use UF-B this time. Run it through a GFCI receptacle before going underground and you'll only need to bury the cable 12 inches.
You don't actually have to pull up the NM-B. Just cut it off underground at both ends and abandon it.
Then investigate why the guts of your old fixture were all corroded, and take steps to ensure that it doesn't happen again.
But you better start digging. And use UF-B this time. Run it through a GFCI receptacle before going underground and you'll only need to bury the cable 12 inches.
You don't actually have to pull up the NM-B. Just cut it off underground at both ends and abandon it.
Then investigate why the guts of your old fixture were all corroded, and take steps to ensure that it doesn't happen again.
#7
08-02-03, 09:21 PM
Much appreciate your help. Question though - you stated to use a GFI recepticle BEFORE going underground. Is that from the lamppost to the house or the other way around. If I am going from the breaker box to outside of the house through a hole in the foundation and then straight into the ground, where would I put this receptacle? I thought I'd use a GFI breaker and then use a GFI outlet on the lamppost. Is this sufficient? Also, I was going to use 14/2 UF wire. Is this sufficient and can I use a 20 amp GFI breaker for this. Please advise. Thank you.
#8
08-02-03, 10:02 PM
Member
The GFCI is at the house end. Either inside before it goes through the siding, or outside just after it goes through the siding (whereever an extra receptacle might be more convenient). If outside, then of course use a waterproof box and cover.
Alternatively, you could use a GFCI breaker. It's a lot more expensive than a GFCI receptacle though. If you use a GFCI breaker, there's no need for a GFCI receptacle on the post. Once GFCI is quite sufficient.
You said it's on a 20-amp breaker. If so, you cannot use 14-gauge wire. Either use a 20-amp breaker and 12/2 UF-B, or use a 15-amp breaker and either 12/2 or 14/2.
Alternatively, you could use a GFCI breaker. It's a lot more expensive than a GFCI receptacle though. If you use a GFCI breaker, there's no need for a GFCI receptacle on the post. Once GFCI is quite sufficient.
You said it's on a 20-amp breaker. If so, you cannot use 14-gauge wire. Either use a 20-amp breaker and 12/2 UF-B, or use a 15-amp breaker and either 12/2 or 14/2.
#10
08-04-03, 07:40 AM
Much appreciate the advice. It turns out that I needed to dig up my lawn and replace the wiring. I used 12/2 UF. I also put in a GFI outlet (which is in the lamppost) and a GFI 20amp circuit breaker. Everything works fine now. Thanks again for the help.
