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Thread: Difference between GFI and GFCI

  1. #1
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    Difference between GFI and GFCI

    hi, good day.. pls help, im a little bit confuse. i just want to know if there's a difference between GFCI and GFI? i have a friend who says that GFCI is for the OCPD in the electrical panels, while GFI is for the individual outlets that has a ground fault current protection. please advise..

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    Quote Originally Posted by jojo View Post
    hi, good day.. pls help, im a little bit confuse. i just want to know if there's a difference between GFCI and GFI? i have a friend who says that GFCI is for the OCPD in the electrical panels, while GFI is for the individual outlets that has a ground fault current protection. please advise..
    A GFCI is either a breaker in a panel, or a receptacle. A GFI is a piece of equipment, usually in switchgear that detects a ground fault, and is usually in big services -Greater than 400A. It needs to be set correctly to the service size. Thats about all I know about it, being a resi guy.

    ~Matt
    I would rather beg for forgiveness then beg for permission.

  3. #3
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    There is no difference between the terns GFCI and GFI. The latter is just a lazy slang version of the GFCI. The NEC does not even contain the term GFI.

    Regarding large wye services as Matt mentioned, they use the term GFPE which has a little different meaning than GFCI.

    230.95 Ground-Fault Protection of Equipment.
    Ground-fault protection of equipment shall be provided for solidly grounded wye electric services of more than 150 volts to ground but not exceeding 600 volts phase-to-phase for each service disconnect rated 1000 amperes or more. The grounded conductor for the solidly grounded wye system shall be connected directly to ground through a grounding electrode system, as specified in 250.50, without inserting any resistor or impedance device.
    The rating of the service disconnect shall be considered to be the rating of the largest fuse that can be installed or the highest continuous current trip setting for which the actual overcurrent device installed in a circuit breaker is rated or can be adjusted.
    Exception: The ground-fault protection provisions of this section shall not apply to a service disconnect for a continuous industrial process where a nonorderly shutdown will introduce additional or increased hazards.
    Rob

    Chief Moderator

    All responses based on the 2011 NEC unless otherwise noted

  4. #4
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    thanks for your advises matt and rob. i was also correct in thinking that either the device is a receptacle or a circuit breaker protecting the feeders, still it is a GFCI. i mean GFI and GFCI is no different. i really appreciate your help..
    Last edited by jojo; 07-19-10 at 06:29 AM.

  5. #5
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    Quote Originally Posted by jojo View Post
    thanks for your advises matt and rob. i was also correct in thinking that either the device is a receptacle or a circuit breaker protecting the feeders, still it is a GFCI. i mean GFI and GFCI is no different. i really appreciate your help..
    You are correct that GFI and GFCI are the same; however, unlike GFPE-which protects equipment, GFCI protects people.
    "Electricity is really just organized lightning." George Carlin


    Derék

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    Quote Originally Posted by jumper View Post
    You are correct that GFI and GFCI are the same; however, unlike GFPE-which protects equipment, GFCI protects people.
    There is also two clases of GFCI's Class "A" is a 5ma device that as said, is a people protector, Class "B" such as the one required in 426.28 is a 30ma device for the protction against fires caused by heating equipment, UL has allowed the use of AFCI's since they include a Class "B" GFCI in them, since AFCI's have come out, Class "B" GFCI's are getting hard to find.
    Wayne A. From: N.W.Indiana
    Be Fair, Be Safe
    Just don't be fairly safe

  7. #7
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    yeah derek, GFCI is for safety of persons and GFPE is for equipment. i have to admit that im not really familiar the term GFPE. what i know only know is the terms GFCI and AFCI =) Only when i read yesterday about NEC230.95. Its about a circuit breaker with shunt trip. I came to know that there are 2 types of ground-fault equipment protectors: a ground-fault sensor encircling all circuit conductors (including the neutral) and a ground-fault sensor encircling only the bonding jumper conductor. But what if the service disconnect is rated less than 1000A? is GFPE not required?

    @ wayne:thanks for the information regarding the two classes of GFCI. the receptacles in the kitchens and in the wet areas class "A" GFCI's. for class "B" GFCI's i have no idea on its applications for heating equipment. is the class "B" applied for equipments like a microwave ovens?

    thanks for the information guys.

  8. #8
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    Hey jojo,

    GFPE is out of my range of experience. I leave that up to an EE.

    The 30 mA GFCI protection in a AFCI I knew about, but a class "B" GFCI is a new one to me. There is a lot I do not know.
    "Electricity is really just organized lightning." George Carlin


    Derék

  9. #9
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    Class "B" GFCI's are required in these articles:

    424.99(C)(5)
    426.28
    427.22

    And a much missed Class "A" GFCI requirement
    424.44(G) although manufactures have been very good about warning labels on this requirement, and even have built in GFCI's in there supplied controls to meet this requirement, but this wasn't so back a few years.

    I might have missed others?

    I like the idea of using a class "B" GFCI on most cable and element types of heating, as a ground fault somewhere mid cable/element will not always open the OCPD, and this can lead to a fire or shock hazard. so to me it should be required on all resistive type of heating where a ground fault could cause the above to happen.
    Wayne A. From: N.W.Indiana
    Be Fair, Be Safe
    Just don't be fairly safe

  10. #10
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    Quote Originally Posted by jojo View Post
    @ wayne:thanks for the information regarding the two classes of GFCI. the receptacles in the kitchens and in the wet areas class "A" GFCI's. for class "B" GFCI's i have no idea on its applications for heating equipment. is the class "B" applied for equipments like a microwave ovens?

    thanks for the information guys.
    Nope mainly resistive type of heating, not all but some as in the articles I listed above.
    Wayne A. From: N.W.Indiana
    Be Fair, Be Safe
    Just don't be fairly safe

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