GFCI's a good idea?

softdownsoftdown Solar Expert Posts: 3,630 ✭✭✭✭
Left for three days. Came back to a warm fridge due to GFCI getting tripped. Reset and it ran for ~ 1/2 hour. Then it began tripping immediately.

Could be due to a rodent chewing a wire I suppose. But my experience, in general, with GFCI's has been generally horrendous.

If the wiring got sufficiently damaged somehow, I think the circuit breaker will trip and mitigate disaster.

So just replace that GFCI?
First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries

Comments

  • 706jim706jim Solar Expert Posts: 495 ✭✭✭✭
    I used to have them for the outlets on the side of my house. Up here in the north, we plug our cars in during cold nights in January and February. 
    Got so sick of them tripping that I took them out.
    (When is the last time someone got electrocuted by a fridge?)
    Island cottage solar system with 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 29th year.
  • BB.BB. Super Moderators, Administrators Posts: 32,924 admin
    Starting from the basics... There are standard fuses and breakers... And these are usually available in slow or fast trip... Slow trip are usually used on induction motors and other loads that surge for a few seconds and you don't want false trip. And there are fast trip--Can be used on on loads that don't surge--So fast trip can lessen damage/scorched wiring/etc.

    Then the standard & other breaker/protection devices:
    • Standard trip: Normal over current trip breakers--Protect wiring against short circuits and overloads.
    • Ground Fault Detection (roughly over 10 mAmps of "leakage current"--Typically "appliance falls in water, person touches Hot wire and grounded plumbing, near swimming pool, wet grass, etc.) used to help prevent electrocution of people and animals
    • Arc Fault Detection Breakers: Detect the "radio frequency" energy typically generated by sparking/arcing events.
    Ground fault is not there to "protect" the wiring or loads--Just to protect against electrocution (and over current breaker protection if used in main panel breaker slot). Usually required for outlets near sinks, outside, swimming pools, etc.

    I have had several GFI equipped outlets fail (in garage and kitchen). I have even had one fail where the red/black buttons just shattered and spit the springs into the garage sink. Why? No idea. Just cheap plastic in an unheated garage (mild climate).

    I would say that GFI outlets and breakers should only be installed where required by code (near water, outside, etc.). In some cases (older homes, genset, etc.), I have used a GFI adapter cord/plug set on occasion (such as doing emergency repairs in the rain/wet conditions, etc.) just to be extra careful.

    The other type of breaker with Arc Fault detection. As always, check your local codes... Here is one summary for new construction:

    https://www.nyeia.com/where-arc-fault-circuit-interrupter-afci-protection-is-required-in-residential-dwelling-units/

    For new construction, Section 210.12 (A) of the National Electrical Code states that all 120-volt, single-phase, 15- and 20-ampere branch circuits supplying all outlets must be Arc-Fault Circuit-Interrupter protected in the following dwelling unit locations:

    Kitchens, Family Rooms, Dining Rooms, Living Rooms, Parlors, Libraries, Dens, Bedrooms, Sunrooms, Recreation Rooms, Closets, Hallways, Laundry Areas, or Similar Rooms or Areas.

    Even though it is not listed, this includes finished basements because once the basement is finished, the area becomes one of the rooms listed above.

    Adding to the confusion, most people assume that outlets are only plugs or receptacles. However, outlets is defined in Article 100 of the National Electrical Code as “A point on the wiring system at which current is taken to supply utilization equipment”. That means that the requirements for AFCI protection is required in the areas stated above at all 120-volt, single-phase, 15- and 20-amp receptacles, lighting fixtures, switches, smoke alarms, dishwashers, refrigerators, and so on.

     Arc Fault breakers are there to reduce the chances of fire with a "soft short circuit" or wiring connection failure where sustained arcs are generated... Sounds good. But in practice--There have been issues with false trips by brushed (universal) motors used, for example in vacuum cleaners, 120 VAC drills, Skill Saws, and such:

    https://diy.stackexchange.com/questions/37277/what-should-i-do-if-my-vacuum-trips-my-afci-device

    The simple answer is that breakers/outlets (with GFI/AFD) are by nature "unreliable"--Having them on circuits that you want reliable power for (like fridge and freezer).

    If this was a old refrigerator and the GFI tripped... Your first choice would be to replace the GFI device. Probably needed to be replaced.

    There is a possibility that something went wrong in the refrigerator... But modern 120 VAC appliances are designed to have 600 VAC isolation (double insulated if two wire plug) between AC input and the "rest of the device's" electrical wiring (and from the factory, 1,800 VAC minimum hipot tested to get a UL/NRTL Mark).

    Is it possible that your fridge has an electrical problem--But replacing the GFI is most likely the solution.

    As always, the decision is yours... Adding GFI/AFD to a plug in and forget device that you need to run reliably for years on end (fridge/freezer)--It is not worth it for me.

    Alternatives--There are circuit failure alarms:

    https://www.amazon.com/Failed-Circuit-Alarm-New-Style/dp/B0077Q9NC6

    And temperature monitors/alarms...

    https://www.amazon.com/Freezer-Alarm-Refrigerator-Temperature-Monitor/dp/B094783WQ3

    And there are GFI & arc fault Testers:

    https://www.amazon.com/gfci-tester/s?k=gfci+tester

    Adding complexity to detect complexity failure of GFI/AFD complexity... Keeping things simple & reliable. Not a bad solution either.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • softdownsoftdown Solar Expert Posts: 3,630 ✭✭✭✭
    I was cycling this fridge to be primarily off when the sun is down. Mostly used to cool summer drinks is this arid environment. So it owrked pretty hard when the power returned at 8am. Wondering if that contributed.

    This GFCI is being tossed. Not the first time it has failed. Plus I bought it used - as with so many other things.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • checkthisoutcheckthisout Registered Users Posts: 31 ✭✭
    softdown said:
    Left for three days. Came back to a warm fridge due to GFCI getting tripped. Reset and it ran for ~ 1/2 hour. Then it began tripping immediately.

    Could be due to a rodent chewing a wire I suppose. But my experience, in general, with GFCI's has been generally horrendous.

    If the wiring got sufficiently damaged somehow, I think the circuit breaker will trip and mitigate disaster.

    So just replace that GFCI?
    Defrost elements often throw gfci's for a loop.

    I think you found your solution. Get rid of the gfci on the fridge circuit.
  • Dave AngeliniDave Angelini Solar Expert Posts: 6,304 ✭✭✭✭✭
    And get rid of GFCI on critical pump circuits and any other circuit that is important to an offgrid application. 
    "we go where power lines don't" Sierra Nevada mountain area
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • softdownsoftdown Solar Expert Posts: 3,630 ✭✭✭✭
    GFCI's - another "wonderful idea" with frequently disastrous results.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • RCinFLARCinFLA Solar Expert Posts: 1,475 ✭✭✭✭
    Problem is too many occurrences where the metal housing is not properly grounded.  There are several opportunities for missed or improper grounding connections in path back to main panel.  Appliance works fine and proper grounding is seldom checked.

    In 2017, a 12-year-old girl was electrocuted after climbing over a chain link fence and coming down on top of an outside air conditioner unit with one side of AC shorted to its metal case which was floating and did not have the A/C metal housing connected to ground. NEC code now requires outside units, including 240vac units, have GFCI breakers.

    Several years after moving into my new house my 240vac 2 hp sprinkler pump crapped out.  When I went to install a new pump I discovered the ground wire was never connected to pump casing.

    I had an addition put on my house.  After the so called 'licensed' electrician left I checked all the outlets in the new room with one of the simple LED plug-in checkers.  Two outlets did not have ground wire connected.
  • softdownsoftdown Solar Expert Posts: 3,630 ✭✭✭✭
    Problem is GFCI's crap out when an appliance "sneezes".

    "12 year old girl". Could you appeal to emotions a little harder next time? 40,000 girls and boys die on our roads every year. Clearly the speed limit needs to be 5 mph.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • JRHillJRHill Registered Users Posts: 150 ✭✭
    I've had multiple ground fault devices fail over the years. Most recently a 2 pin on the power cord of my pressure washer. I just put a standard plug on it since the circuit is already protected in any place I'd use it. The thing is they don't have my trust, in general. "Testing" them with the built in push buttons is a joke to me. I don't believe that does any more than a cycle the mechanical aspects. The only way to really know is to introduce an actual ground fault. Yeah, I know there are test devices but if you trip it once, will the thing work likewise again without testing it - and on and on.

    Softdown, you are a cool guy. I fully understand your point. But if one life could be saved with a functional $20 device its worth it, little girl or old fart like me. But once someone heads down the save everybody road at all costs there is no end. To me, I subscribe to the "When it's time, its time camp" sprinkled with some common sense, whatever that is and where it can be found.
    Off Grid. Two systems: 1) 2925w panels, OB VFXR3648, FM80, FNDC, Victron BMV-712, Mate3s, 240 xformer, four SimpliPHI 3.8; 2) 780w, Morningstar 30a, Grundfos switch, controller and AC/DC pump, 8 T105. Honda EU7000is w/AGS. Champion 3100. HF 4550, Miller Bobcat.
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