swimming pool lighting...... geez.

[Fulthrotl]

ok. service call to a residence.

pool with attached jacuzzi. both have pentair pool lights, 120 vac.

breaker is tripped. when reset, and lamps turned on with switch.
breaker trips. breaker is 20 amp.

GFCI does NOT trip.

i replace GFCI, just for drill. brand new leviton GFCI blank face,
after the light switch. test gfci downstream. it works correctly.

disconnect both lights at their respective junction boxes, and
reset the breaker, and turn the switch on. breaker holds.
gfci holds. premises wiring to box is good.

120 volts at the junction box.

i hook up the first pool light. it goes on, pulls 4 amps. lights up
fine. i disconnect it, and hook up the second pool light. it goes
on as well, pulls 4 amps. lights up fine.

i shut the switch off, hook both of them up, turn it on, breaker
holds for about 2-3 seconds, pulling 20 amps, and breaker trips.

GFCI does NOT trip. at all. ever.

any thoughts on this one?


randy

 

[Dennis Alwon]

could it be the wiring between the 2 lights is shorting out.

 

[Fulthrotl]

could it be the wiring between the 2 lights is shorting out.

both j boxes are a foot apart, and the wiring between them (pipe nipple)
is fine, and holds power without tripping. so... that leaves the two cords
going down to the fixtures.

as nutty as it sounds, it seems that 20 amps of current is flowing
between the fixtures, simply tripping the breaker from overcurrent
without going to ground and faulting the GFCI.

everything i know about ohms law, and GFCI's says this can't happen.

twenty amps of current flows when BOTH 4 amp fixtures are connected.
either fixture connected alone, draws only 4 amps.

 

[Dennis Alwon]

I have no idea-- something is crazy.

 

[Fulthrotl]

I have no idea-- something is crazy.

yep. we are in complete agreement.

 

[220/221]

any thoughts on this one?

Start over?





I hate pool lights. We spent about 4 hours replacing one last week. Someone else pulled it out, along with the cable, and somehow got their fish tape stuck in the 1/2" rigid brass conduit.

Had to go in from the niche and get ahold of their fish hook and pull it thru.

No problem.



Big, old school niche about 3' below the surface. Problem. Can't do much from above.

No markings on the fixture but it looks pretty standard with a retainer at the bottom and a screw at the top. Problem. New fixture is close, but not exact.

Salt water pool. Big problem. It's bad enough that the fixture wants to float up but even when I let out all of my air, I float up after about 3 seconds. I also have no goggles.

I tried tieing a cinder block to my belt but that just wanted to pull me farther sway from the wall. :roll:

I can't get the thing to seat right and I finally determine that there are a couple tiny brass pieces that won't allow the fixture to go all the way in. I break them off and try again. I get close but cant stay down long enough to get the screw started. After 20 attempts, I determine that the screw is too short.

Drive to True Value and get a 10/24 x 2" brass screw and some goggles and finally got it done.

The pool light COST me $212 so they are going to crap when they see the bill.

 

[dbuckley]

Using a breaker as an ammeter is an imprecise tool.

Get a clamp around those wires and see where the current is really going.

'Cos we all know this makes no sense...

 

[Fulthrotl]

Using a breaker as an ammeter is an imprecise tool.

Get a clamp around those wires and see where the current is really going.

'Cos we all know this makes no sense...

sorry. there was a fluke 337 clamped around the offending wire.
that's how i knew each of the lights individually drew 4 amps.
and collectively, they draw 22 amps.

my gut hunch on this one is that it's been that way for a while,
and the high draw finally toasted the breaker so that it won't hold
the current any more... the first couple time i tested, it held for
2 seconds, then it was instant trip, as it warmed up.

 

[Fulthrotl]

by the way, the fault tree on this one, for me, goes like this:

there are three things i can do here.....

1. replace both lights with LED pool lights, in 12 volts,
with a 120 volt / 12 volt dry type transformer to supply them,
fed from a gfci protected circuit.
(for personal reasons, i will NOT install a 120 volt wet niche
fixture. get someone else. sorry. not negotiable)

2. cut the cords to the lamps off flush with conduits, so that
they CAN NOT be attached to the circuit again by anyone
else.

3. drive over to the building department, and file a written report
of a safety hazard.

i will do one of these things by close of business Wednesday.

professionally, i'm just puzzled, wanting to know what the hell is
going on here..... i already have a plan to fix it..... ;-)

 

[dbuckley]

there was a fluke 337 clamped around the offending wire.

Well, in Fluke we trust, so clearly that's the current flowing.

that's how i knew each of the lights individually drew 4 amps. and collectively, they draw 22 amps.

Still makes no sense

 

[WinZip]

Assuming each light is 500 watt / 120 volt = 4.16 amp how in the world are you getting 20 amp , something really fishy going on , so at each pool box you have a feed in an the light cord correct.

 

[WinZip]

For the hell of it connect 2 100 watt lamps to the pool box feeds see if same happens , next connect first pool light with feed connected to box 2 dont connect box 2 light light , if it holds connect light 2 , pulling my hair out thinking this out because I do alot of this work.

 

[WinZip]

Also do these light have a motor in them that dial turns to different color ?

 

[hurk27]

sounds like there is a metallic path between the lights that is not a path to ground or is a path to the supply EGC, and one or both of the lights has faulted to this metallic path, one with the neutral and one with a hot, so when you hookup both lights it completes the path from neutral to hot?

we know there is not a ground fault because of the GFCI not tripping, so the only other fault would be hot to neutral which the GFCI just passes back to the breaker in the panel.

Long pathway 5.4 ohms in circuit = 22 amps at breaker.

only thing that would make sense to me?

is there any transformers involved with these lights?

 

[WinZip]

ok. service call to a residence.

pool with attached jacuzzi. both have pentair pool lights, 120 vac.

breaker is tripped. when reset, and lamps turned on with switch.
breaker trips. breaker is 20 amp.

GFCI does NOT trip.

i replace GFCI, just for drill. brand new leviton GFCI blank face,
after the light switch. test gfci downstream. it works correctly.

disconnect both lights at their respective junction boxes, and
reset the breaker, and turn the switch on. breaker holds.
gfci holds. premises wiring to box is good.

120 volts at the junction box.

i hook up the first pool light. it goes on, pulls 4 amps. lights up
fine. i disconnect it, and hook up the second pool light. it goes
on as well, pulls 4 amps. lights up fine.

i shut the switch off, hook both of them up, turn it on, breaker
holds for about 2-3 seconds, pulling 20 amps, and breaker trips.

GFCI does NOT trip. at all. ever.

any thoughts on this one?


randy

Is it wired this way and I know you know what your doing this is just a question - from breaker to line side of gfi then from load side gfi to light switch then onto the pool junction boxes with nothing else on that circuit.

 

[Fulthrotl]

sounds like there is a metallic path between the lights that is not a path to ground or is a path to the supply EGC, and one or both of the lights has faulted to this metallic path, one with the neutral and one with a hot, so when you hookup both lights it completes the path from neutral to hot?

we know there is not a ground fault because of the GFCI not tripping, so the only other fault would be hot to neutral which the GFCI just passes back to the breaker in the panel.

Long pathway 5.4 ohms in circuit = 22 amps at breaker.

only thing that would make sense to me?

is there any transformers involved with these lights?

just straight 500 watt incandescent. no motors. no theme park lighting.
no xfmr's.

i'm of the same opinion as you are, that there is simply a large load
that is across the lamps, going from hot to neutral, without
leaking to ground. that only exists when BOTH lamps are
connected to the same wire. it doesn't exist solely in one lamp or the
other. they both have to be hooked up for it to happen.

something i have not dug into yet, is the pool pump was running
during this testing. it's on it's own 220 volt 20 amp circuit,
and that still doesn't make any sense, cause the only return path
that will not fault the GFCI is thru the lamp neutral.

and the gfci trips on 7 milliamps. i measured it with my spiffy doodle
ideal suretest tester, that knows all things.

my head hurts. i need a nap now.

 

[Fulthrotl]

Is it wired this way and I know you know what your doing this is just a question - from breaker to line side of gfi then from load side gfi to light switch then onto the pool junction boxes with nothing else on that circuit.

the light switch is ahead of the GFCI, other than that, yes. it's a textbook
install.

 

[hurk27]

the light switch is ahead of the GFCI, other than that, yes. it's a textbook
install.

could the equal potential bonding have been ran between these two fixtures with an insulated wiring method, but not run any further or the next jumper lost connection leaving this run as an isolated run just between the two fixtures, and now you have a hot grounded out to it, and a neutral in the other grounded out to it?

Ok thats a little far fetched but all that I can think of, have you had the lamps out?

 

[WinZip]

If he was near by I would love to trouble shoot this crazy thing , I would try connecting 2 different lamps the the switch leg at the pool boxes , could be a problem with one or both lights.

 

[hurk27]

just checking between the two lamp circuits after the split with a ohm meter would confirm the above hypothesis?
you will be looking for the neutral in one circuit shorted to the hot in the other?