Samsung Refrigerator Tripping GFCI

[winnie]

The special purpose GFCIs require a ground check conductor. If the SPGFCI can not verify the equipment grounding conductor, the device opens the circuit, even without any leakage current.

Well that is simpler logic than I was speculating about.

Given that SPGFCI is already in the code for industrial applications, I wonder if it would be less of a push to get it as an exception for general 120V applications.

In other words keep the requirements for general purpose 5 mA class A GFCIs, but add an exception which permits SPGFCI type approaches for plugged in stationary equipment such as appliances with VFDs.

I bet that in actual practice, 100mA leakage threshold, combined with assured EGC would provide better safety than a 5mA leakage threshold.

Jon

 

[don_resqcapt19]

Well that is simpler logic than I was speculating about.

Given that SPGFCI is already in the code for industrial applications, I wonder if it would be less of a push to get it as an exception for general 120V applications.

In other words keep the requirements for general purpose 5 mA class A GFCIs, but add an exception which permits SPGFCI type approaches for plugged in stationary equipment such as appliances with VFDs.

I bet that in actual practice, 100mA leakage threshold, combined with assured EGC would provide better safety than a 5mA leakage threshold.

Jon

The SPGFCI has a 20 mA trip, but uses the same time to trip formula as does the Class A GFCI. One issue is that these are stand alone type devices and not available as a breaker or a receptacle. Often the stand alone trip device is used with a shunt trip breaker to clear the circuit.
There was a Public Input to permit the use of SPGFCIs for 210.8(F) but it was rejected at the task group and unlikely it will be accepted in the full committee meeting in Jan.

 

[LarryFine]

I believe, and others have said, that the concern is more about accidental contact with plug blades while plugging and unplugging by kitchen personnel than about appliance grounding malfunctions.

 

[jim dungar]

Well that is simpler logic than I was speculating about.

Given that SPGFCI is already in the code for industrial applications, I wonder if it would be less of a push to get it as an exception for general 120V applications.

In other words keep the requirements for general purpose 5 mA class A GFCIs, but add an exception which permits SPGFCI type approaches for plugged in stationary equipment such as appliances with VFDs.

How would the ground sense work for 2 wire devices or when a three wire cord is removed and the receptacle is empty?

 

[winnie]

IMHO if a 2 wire device has more than 5 mA of leakage, then you have a real shock hazard and the GFCI should trip.

I could imagine a device that looks and acts as a regular GFCI with 5mA trip threshold. However if a ground sense lead gets attached properly the sense threshold gets changed to 20 mA.

Plug your stationary appliance in, attach the ground sense lead, and the chance of nuisance trip gets greatly reduced.

Plug in an ordinary appliance, get ordinary protection.

Jon

 

[don_resqcapt19]

How would the ground sense work for 2 wire devices or when a three wire cord is removed and the receptacle is empty?

An SPGFCI cannot be used on equipment that does not have a connection to an EGC. Not sure they are intended for cord and plug connected equipment and doubt there will ever be a breaker or receptacle version of this device.

 

[winnie]

I think there would need to be a substantiated proposal to allow such devices in the first place.

But it seems a good solution to providing improved protection to stationary appliances without increasing nuisance tripping such as started this thread.

 

[garbo]

Before retiring from a large hospital they had an expensive maybe 8' wide refrigerator with three large doors on both sides. One side was in a clean room where they mixed drugs and over side was for puck ups. Unit would trip a 120 floor 20 amp bolt on GFCI circuit breaker every few days. Guys replaced GFCI breaker twice but still tripled. I spent over a hour examine wiring. Disconnected the control board and meggered every wire & compressor. All megger reading were great. Replaced GFCI 5 ma trip breaker with a 30 ma trip equipment 20 amp single pole GFCI circuit breaker and never tripped again. Unit did not have a VFD and never found any moisture on wires or luminares. Frustrating for sure. Rooms had plenty of light and I wanted to disconnect one side of luminares for a week to see if 5 ma GFCI tripped but they said they could not have luminare off.

 

[kwired]

Before retiring from a large hospital they had an expensive maybe 8' wide refrigerator with three large doors on both sides. One side was in a clean room where they mixed drugs and over side was for puck ups. Unit would trip a 120 floor 20 amp bolt on GFCI circuit breaker every few days. Guys replaced GFCI breaker twice but still tripled. I spent over a hour examine wiring. Disconnected the control board and meggered every wire & compressor. All megger reading were great. Replaced GFCI 5 ma trip breaker with a 30 ma trip equipment 20 amp single pole GFCI circuit breaker and never tripped again. Unit did not have a VFD and never found any moisture on wires or luminares. Frustrating for sure. Rooms had plenty of light and I wanted to disconnect one side of luminares for a week to see if 5 ma GFCI tripped but they said they could not have luminare off.

Was GFCI even required on this? If so sounds like something that likely has option to hard wire and then likely wouldn't need GFCI.

 

[ptonsparky]

FWIW, I've installed meters capable of measuring mA in series with the EG conductors. That way you know what level your dealing with. Gar would have suggested a series resistor, with a voltmeter in parallel with it.

 

[farmantenna]

here in Massachusetts we're using 2023 NEC so ALL Kitchen receptacles need to have GFCI protection . So let the chaos begin! We had 1600 ! electric ranges tripping GFCI circuit breakers throughout the state and because it was such a problem with tenants using hot plates and extension cords just to cook, the state fire marshal and governor had to get involved with emergency exception procedure. Basically, put in the $90 CB and if it's a problem document, it's a problem, then get inspector's permission to put in $18 CB. Disaster

 

[ptonsparky]

I don't know if I've ever seen a range or dryer with a proper 4 wire connection made up by an appliance store. I always checked ranges in new homes. Dryers if they were there.

 

[garbo]

Was GFCI even required on this? If so sounds like something that likely has option to hard wire and then likely wouldn't need GFCI.

Yes it was hard wired and it was most likely in the contract when they performed a remodel.

 

[ramsy]

I doubt that the change in UL 943 to address the high frequency leakage issue will be far enough along for a GFCI-HF to be on the market for 3 or 4 more years.

Perhaps never, if no GFCI or NRTL is required where appliance is manufactured, before purchased on the internet & shipped.

Samsung refrigerators.. are manufactured in South Korea, the U.S.A, Germany, China, Hungary, South Africa, Luxemburg, Sweden, and India.

Many of these countries adopt the self-regulated CE mark, with 230vac appliances using 1/2 the current of 120v loads, on RCD breakers.

4 types of RCD devices detect AC, DC currents, and varying frequencies.

As long as RCD's are not adopted, and UL listing standards / NRTL's remain unenforceable with internet sales, knuckle-head US contractor's and their GL policy remain liable for all appliance incompatibility hazards, when the required GFCI or AFCI are bypassed by the knuckle head.

 

[Doc13067]

Yes, it would matter. The NEC requirement is for the receptacle location, not what’s plugged into it.

The refrigerator has an EGC. It’s safe near the sink. The reason that the code is written the way it is, is to prevent someone plugging in a portable appliance with a 6’ cord into a non-GFCI protected receptacle and allowing that appliance to reach the sink.

Yeah that’s true it does specifically talk about two wire plugs. But if the neutral and ground were touching somewhere would the breaker trip? And with water right next to something that may have a neutral to ground fault I was just being cautious. I’m going to do a continuity check on the plug just to make sure that’s not the issue and if it is not I’ll probably put in a regular receptacle. Although it will be extremely annoying that Samsung made a refrigerator that doesn’t work with GFCIs.

 

[Fred B]

Yeah that’s true it does specifically talk about two wire plugs. But if the neutral and ground were touching somewhere would the breaker trip? And with water right next to something that may have a neutral to ground fault I was just being cautious. I’m going to do a continuity check on the plug just to make sure that’s not the issue and if it is not I’ll probably put in a regular receptacle. Although it will be extremely annoying that Samsung made a refrigerator that doesn’t work with GFCIs.

Seeing a lot of equipment that is using components or design factors that create such an issue in an attempt to meet energy codes without considering implication on electrical code requirements. Consider HVAC equipment that has forced a TIA to be issued regarding GFCI installation on the larger equipment outlets on exterior of bldg.

 

[winnie]

Consider HVAC equipment that has forced a TIA to be issued regarding GFCI installation on the larger equipment outlets on exterior of bldg.

I think the SPGFCI approach would be ideal for minisplits. Allow greater leakage but require a solid ground which is validated. If the required EGC opens, then the breaker trips.

The biggest problem would be hacks defeating the ground check system rather then installing the check wire.

Jon

 

[Fred B]

I think the SPGFCI approach would be ideal for minisplits. Allow greater leakage but require a solid ground which is validated. If the required EGC opens, then the breaker trips.

The biggest problem would be hacks defeating the ground check system rather then installing the check wire.

Jon

The 4-6mA is established threshold for personal protection (reasoning to add GFCI protection to exterior equipment) and the SPGFCI is 20mA far above the "let go" value. Would not be recommending a SPGFCI as substitute for that reason.

 

[kwired]

Yeah that’s true it does specifically talk about two wire plugs. But if the neutral and ground were touching somewhere would the breaker trip? And with water right next to something that may have a neutral to ground fault I was just being cautious. I’m going to do a continuity check on the plug just to make sure that’s not the issue and if it is not I’ll probably put in a regular receptacle. Although it will be extremely annoying that Samsung made a refrigerator that doesn’t work with GFCIs.

Yes, GFCI's have neutral to ground fault protection built into them. Doesn't need to be any load current for it to work. The device injects a signal into the output, if there is a neutral to ground fault current makes its way back to the source and then out to the GFCI via supply side neutral completing a circuit - but this current is enough to unbalance the sense coil since it is only on one of the protected conductors so the normal GFCI functioning is what initiates the trip. If they did not have the signal injection feature then it wouldn't trip unless until enough load current flows to trip the GFCI.

 

[winnie]

The 4-6mA is established threshold for personal protection (reasoning to add GFCI protection to exterior equipment) and the SPGFCI is 20mA far above the "let go" value. Would not be recommending a SPGFCI as substitute for that reason.

Agreed that the 20mA threshold is not as safe as the 4-6mA class A protection.

But the combination of 20mA protection with enforced EGC connection changes this balance. 20mA through a person is a significant hazard. 20mA through the EGC not so much.

Remember that we are talking about equipment fastened in place, where the danger is that the EGC fails, and a separate failure energizes the chassis.

Jon