Strange landscape lighting issue 120v

[Mustwin351]

Have 5 landscape lights controlled by a single indoor light switch. Lights come on for maybe about a minute and then all go out. Turn off the switch and turn back on and they are still out. After waiting about 5 minutes and turning the switch on they come back on but then all of them go out again after about a minute. I'm guessing the most likely scenario is a loose connection at some point in the circuit breaking continuity in the circuit?

Just thought I might get some ideas before I go through the wiring which is a rats nest at best.

 

[JFletcher]

Sounds very much like what happens when a 100W bulb is in a 60W recessed can with a thermal trip; comes on, overheats, bimetallic strip lifts, light goes out, cools, strip makes contact again, light come on, cycle repeats.

I'd take a look at the bulbs to see if they overlamped. and to make sure they are 120V and not LV fed from a xfmr, one that maybe has a similar thermal cutout or is failing.

eta: a poorly placed photocell might also be the culprit

 

[Mustwin351]

Sounds very much like what happens when a 100W bulb is in a 60W recessed can with a thermal trip; comes on, overheats, bimetallic strip lifts, light goes out, cools, strip makes contact again, light come on, cycle repeats.

I'd take a look at the bulbs to see if they overlamped. and to make sure they are 120V and not LV fed from a xfmr, one that maybe has a similar thermal cutout or is failing.

eta: a poorly placed photocell might also be the culprit

Good thought but I know that none of my lights are overlapped but I will try lamping each fixture one at a time to rule out maybe a faulty overload. I wouldn't imagine older landscape fixtures would have overloads but maybe so.

 

[JFletcher]

Good thought but I know that none of my lights are overlapped but I will try lamping each fixture one at a time to rule out maybe a faulty overload. I wouldn't imagine older landscape fixtures would have overloads but maybe so.

Gotcha. So, these 5 lights are all incandescent 120V; no MH or HPS? No photocell in the circuit? Odd problem indeed; faulty circuits dont usually open/close/open/close themselves.

The switch itself could be on its last legs. I'd be surprised if the fault is in any of the wiring itself, especially if the fault time is reproduceable with more than a few cycles.

eta: it could be a bad connection heating up and losing continuity, tho for all 5 to go out it would have to be somewhere between the switch and first fixture

 

[curt swartz]

I have never seen an incandescent landscape fixture with a thermal cutout. As has already been suggested these fixtures are doing exactly what they would do if there was a photocell between the switch and the fixtures.

 

[dmxtothemax]

RE - "faulty circuits don't usually open/close/open/close themselves".

Not true my friend

seen it many times

loose high resistance joint - pass current thru it - heats up - becomes open circuit
lights go out - current stops - loose joint cools down again - becomes high resistance again
lights come on again - etc etc etc.

 

[Mustwin351]

RE - "faulty circuits don't usually open/close/open/close themselves".

Not true my friend

seen it many times

loose high resistance joint - pass current thru it - heats up - becomes open circuit
lights go out - current stops - loose joint cools down again - becomes high resistance again
lights come on again - etc etc etc.

Very correct I have seen that too and was thinking that was the case here....but after a long search I finally found the photocell hidden on a wall under some vines. Problem solved. Thanks for you help guys.

 

[mgookin]

Very correct I have seen that too and was thinking that was the case here....but after a long search I finally found the photocell hidden on a wall under some vines. Problem solved. Thanks for you help guys.

+1

 

[JFletcher]

Very correct I have seen that too and was thinking that was the case here....but after a long search I finally found the photocell hidden on a wall under some vines. Problem solved. Thanks for you help guys.

:thumbsup: