Pentair light equipped with "low water safety device"

bizzle

Well-known member
Aug 31, 2017
231
Imperial County, CA
I have my spa drained and the light is a full sized pentair with a blown bulb. I have it all disassembled and was trying a regular bulb (tried a flood and a CFL) in it to test the light switches but no lights are working.

I noticed on the label it says that it has a "low water safety device." Does this mean it has some kind of components that keep the light from coming on unless it's submerged and that could explain the reason why a regular light in it with it all disassembled won't work for testing?
 

bizzle

Well-known member
Aug 31, 2017
231
Imperial County, CA
It's not on a GFCI. It has always, as far as I know, been on a normal breaker since the 70s. Small wonder no one has been harmed in the past decades! I have a GFCI to put it on, but I'm testing it first (spa is drained currently anyway). I am testing from the breaker to the junction and the junction to the open fixture, but if there is an automatic shutoff without water being sensed then I won't get juice even if there's nothing wrong with the wires.
 

bizzle

Well-known member
Aug 31, 2017
231
Imperial County, CA
Well then I'm confused. I've tested the wires to the light and they are correct. I already knew the light was blown when I removed it. I was just checking it with a regular light bulb but it won't light up even directly wired to a breaker. The last thing to check is just put it all back together with a new bulb and gasket and hope it works despite all the testing showing there's no reason to suspect it will.

I just didn't want to waste time buying a bulb and wasting a gasket if I'm going to have to end up buying an entirely new light assembly but that's where it's at it seems.
 

kadavis

TFP Guide
In The Industry
Apr 5, 2015
1,579
tucson, arizona
One other test you could do is to disconnect the light cord from the power and check continuity on the black to white and you should have no resistance with no bulb. Then put a known good bulb in and check black to white and see what you get. Also without bulb check black to green also should be no resistance, if there is fixture is bad. If this light is that old maybe you would be better off replacing entire light with new. Good luck
 

bizzle

Well-known member
Aug 31, 2017
231
Imperial County, CA
One other test you could do is to disconnect the light cord from the power and check continuity on the black to white and you should have no resistance with no bulb. Then put a known good bulb in and check black to white and see what you get. Also without bulb check black to green also should be no resistance, if there is fixture is bad. If this light is that old maybe you would be better off replacing entire light with new. Good luck
Thanks for the testing advice. I'll try that first thing in the morning or if I get itchy fingers in a few :)

The fixture label dates it to 2008, but the pad and sub-panel appear to be original. I only inherited the pool in November, 2017 so it's been a bit of a puzzle going through everything.

But just to confirm, you guys are certain that a label declaring, "low water safety device" is only referring to shutting the bulb down if it gets too hot and not in reference to some kind of device in the fixture that would pre-emptively shut it down due to failing to sense enough water?
 

kadavis

TFP Guide
In The Industry
Apr 5, 2015
1,579
tucson, arizona
When the water level is low enough to expose the light lens then internally the light starts heating up and should cut off power to the light. The sensor doesn't detect water level just heat from lack of water around housing