GFCI/GFI Question-

[executive411]

We just spent the past three hours running around the backyard trying to figure out what was going on with our setup...

the system consists of 6 16 channel controllers- it has been working fine for about 5 days. it rained a few times and it rained again yesterday, and everything stopped working correctly...

1 controller (01) was working perfectly-The other controllers all had issues related to the GFI outlet tripping.

On controller 5, we isolated the channels that were causing the GFI to trip- and that was no problem.

On controller 6, it seemed like it was an issue with the amperage, but it was not consistent. This controller has 4 channels connected out of channels 1-8. When any two of these were plugged in, the breaker tripped. When just one of the four were connected, it worked just fine. All channels were less than 4 amps, and combined it's less than 16 ( we upgraded the fuses to 20 Amps)

Controller 3 has a similar issue- all 8 channels are being used-when 7-8 of the channels are on, the GFI trips. but it's not the exact channels each time. All but channel 4 would work fine, then I turn off channel 4 (a 5 amp channel) and turn on channels 1,2,3 one at a time, and more often than not it tripped the breaker-(each one is about an amp)

It's the inconsistent tripping that's confusing me here...

All circuits were tested with a Kill-o-watt meter, and tracked in a spreadsheet to make sure everything was within limits...

Should I break off any ground plugs after the controllers? What can I do to isolate the problem more?

[SBontempo]

If controller 1 is working the way that it should be, how about swapping it out with one of the ones that is tripping the outlet and vice versa. This will help narrow down whether or not you are running into a bad GFI socket.

Steve

[Dennis Cherry]

GFCI's work on ground faults, probably not the current issue. Are you using any old strings of lights? Sometimes the insulation breaks down and gives you a ground fault. I have seen a ground fault where a set of chasing lights was loosely sandwiched between two sheets of colored acetate laying (not sealed) on the ground and got condensation on the lights. using a DVM ohm meter is the way I found the high resistance ground. Disconnected the lighs and the problem went away.

Also sometimes old lights wrapped on metal frame objects will give you a problem.
Are your plugs sealed using plastic bags or tape? You might want to take it off so the water can drain off , UL has tested the lights for outdoor use without stating you need to seal them better, so leave them open and connected properly, elevate them off the ground so the plugs and sockets are not in standing water, and position any unused female receptacles with the openings facing down so water will not go inside. I have done all the above and not one trip this year so far.

[executive411]

OK thanks for the advice- how do I use a ohm meter to test the circuit-and what exactly am I looking for?

[friskybri]

I also have a GFI question. I put in a 20 amp breakers, wire and GFI's to different locations on the outside of the house. I plan on putting 8 icicle channels, 4 rope light channels and 4 mini light channels for one controller. I used kill a watt to check the amps from everything I have. Total amps drawn on lights for this controller is 16 amps. From what I see most use two different Gfi outlets for one controller. Is it ok to use one 20 amp GFI and plug both sides into the one duel outlet? Most of my controllers wont be pulling more then 20 amps max per controller or 10 per side. How much power does the pc boards pull?

[Dennis Cherry]

You need a good DVM (Digital Volt Meter) set it to OHMs

Turn POWER OFF on the controller you are testing but leave the power cords connected to the controller.

Disconnect a light string at the controller from a channel, put one probe in the Ground (round) receptacle on the controller or the extension cord if it is a three wire cord , and then put the other probe across both the blade pins on the string or extension cord plug.

What you want to do is NOT read any resistance from either the power and common wires to the safety ground. If you have any resistance reading that could mean you have leakage to the safety ground.

Watch that you do not touch either probes with your hands or you could be reading your own body resistance not a ground resistance.

If resistance even above 1 Meg is indicated, then disconnect the last string of lights on the circuit you are testing or go to the middle string of lights on a long series string and disconnect it. Go back and see if the resistance went to infinity or you are still reading a resistance.

If infinity then your possible problem is some where in the disconnect strings so reconnect and go the the halfway point of the possible bad strings and disconnect again, keep doing this till you find what string is leaking to ground.

Do the opposite if the resistance is in the first half of the strings.

Now one thing to keep in mind is ground resistance can come and go just by moving the wires, so be very careful not to move the light strings when disconnecting or reconnecting. When reconnecting make sure your resistance is still there before disconnecting other strings or you could be chasing a blind dog.

Once you find the possible string at fault, visually check every inch before touching it, you might find the problem and know how to correct it, like a bulb in water or a cut insulation, once you think it is fixed, plug it back in or replace the string and check the resistance again to make sure it is at infinity.

I know is might sound complicated but it is hard to find and understand what went wrong so you know how to avoid doing a ground fault problem on other channel.

I have been in electronics in troubleshooting for over 50 years, you have to make a plan on how to troubleshoot a problem without distributing the problem so you can confirm you actually found the problem.

[-klb-]

Also, if you are running grounded cords out to the elements, make sure your elevated connections have the female ends facing down. I've seen where the ground socket fills with water, and a puddle, or even film between the socket and plug caused enough of a path. Keeping them facing down prevents the cord ground from getting wet and becoming a path..

As to why you can have a situation where no single item trips the GFCI, but several in combination do, you simply have leaks that are smaller than the trip threshold.. I think many GFCI's are set around 4-6mA to trip, so you could have a number of elements with 1mA leaks, and none of them would trip the GFCI, but any four to six of them would...

[Dennis Cherry]

-klb- wrote:

Also, if you are running grounded cords out to the elements, make sure your elevated connections have the female ends facing down. I've seen where the ground socket fills with water, and a puddle, or even film between the socket and plug caused enough of a path. Keeping them facing down prevents the cord ground from getting wet and becoming a path..

As to why you can have a situation where no single item trips the GFCI, but several in combination do, you simply have leaks that are smaller than the trip threshold.. I think many GFCI's are set around 4-6mA to trip, so you could have a number of elements with 1mA leaks, and none of them would trip the GFCI, but any four to six of them would...

Good points

Thanks for adding

[Dad02]

Sounds like we are talking about a few different things here. If you are calling a GFR a "GFI outlet" understand they come in two different sizes, 20a and 15a (much like your breakers), the most common GFR is a 15amp receptacle with a 20amp feed through. If you are using the 15 amp GFR and trying to plug a 15 - 20amp load into it you will have trouble with the outlet tripping (even with a 20amp breaker). Check your wiring and circuit to make sure it's rated for 20amps (12 gauge wire plus the number of items/outlets on the circuit) and check the rating of the GFR.

[executive411]

The electrician who wired up the backyard came in and removed the problem GFI plugs- He didn't recommend it, but went with it cause he didn't know why the outlets were tripping... By the way, all the outlets were sealed with electrical tape, and the the controllers were bagged umbrella style...

[Steven]

Jeff Millard wrote:

Rain water isn't conductive. Water that gets trapped inside bags and tape attracts dirt, which conducts wherever it can attach itself to something in a continuous trace.

This was my experience this year. I don't use plastic bags or tape, but I make sure all connections are off the ground, and all but 2 controllers are powered with ungrounded 2-wire cords. (I got a good deal at a local hardware store for some orange 14-gauge, outdoor-rated, 2-conductor, stranded power cable.)

This year, one GFCI tripped during the 1st rain. I reset it, and apparently rain water from subsequent rains wasn't conductive enough to trip it, after the 1st rain washed all the dirt away.