GFI tripping on low voltage??

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GoldDigger

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Dennis Alwon said:
I think he is asking if drop in voltage will affect the functioning of the gfci but not certain. Which is it Cavie?
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If the voltage seen by the GFCI gets low enough (probably somewhere lower than 60 volts for a 120 volt unit) then it will behave the same way as if it were disconnected completely, namely you would not be able to reset it and have the reset lock in.
But in that case, the connected equipment would not be working either, so I would not consider it either a nuisance or unexplained trip if that is part of the OP's concern.
I would hope that an up-to-date listed GFCI would not fail to trip on current just because the voltage went too low, but I don't know whether that is part of the listing tests. :)
 
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Dennis Alwon

Dennis Alwon

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Cavie said:
Is there a distance that will cause a GFI to trip?.
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I have heard that a long distance from the source will cause tripping. I believe that was in the literature many years ago but not sure if that has changed. I try and avoid gfci breakers and use gfci receptacles instead
 
Dennis Alwon

Dennis Alwon

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GoldDigger said:
The descriptions of GFCI circuitry and design here seem pretty accurate and potentially helpful. Do you have a good reference to recommend?
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Not really but I did find this from this site

GFCI Limitations
GFCI circuitry has certain inherent limitations that will cause them to open the circuit inappropriately.
These conditions are called: Capacitive Coupling and Spurious Signals. Capacitive Coupling occurs
when long cables are buried in the earth, and the top and bottom parts of the cable act like the plates of a
capacitor. This allows tiny current leaks to occur along the length of the cable. These tiny discharges can
open the GFCI. This is one reason that it is advantageous to locate the GFCI as close as possible to the
electrical load. Spurious Signals occurs when the electrical load of a circuit is changed suddenly due to
turning on or off various electrical devices ? especially all at once. The sudden change unbalances the
current input (black wire) and output (red wire) and the GFCI trips.
Recent Developments
Technology changes in the last 10 years have brought about a variety of similar, but more specialized
devices. These include:
1. Appliance Leakage Current Interrupters (ALCIs)
2. Equipment Leakage Current Interrupters (ELCIs), and
3. Immersion Detection Circuit Interrupters (IDCIs)
ALCIs and ELCIs are devices that react at less than 5 milliamps to interrupt power. ALCIs are
considered personal protective equipment, and not intended to replace GFCIs. ELCIs are equipment
protection devices are intended for sensitive equipment. Immersion Detection devices (IDCIs) are
inserted into appliances and are designed to protect people as their name suggests. Its chief virtue is that
it is designed to function independently of a grounded object. They are not intended to replace CFCIs.
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SG-1

SG-1

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Once the voltage is down to about 100 volts the normal test push button may not work. With the reduced voltage, the current through the test resistor is also less & may be below the trip setting of 4-6mA.
 
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jim dungar

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SG-1 said:
Once the voltage is down to about 100 volts the normal test push button may not work. With the reduced voltage, the current through the test resistor is also less & may be below the trip setting of 4-6mA.
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That will depend on if the GFCI is at the begining of the run or at the end.
 
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jim dungar

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handy10 said:
I am pretty sure that I have seen GFI's that trip if a breaker is turned off in the circuit. I have a three way splitter with a gfi in the cord that trips every time it is unplugged.
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GFCI receptacles will trip if voltage is removed. this has been an OSHA requirement in 'construction cords' for years, but it is only a recent requirement in 'normal' box mounted devices (a primary reason homemade extension cords were discouraged).
 
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