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Thread: Do I really need a 20-amp circuit for this?

  1. #21
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    Quote Originally Posted by Dennis Alwon View Post
    Where does the code specify primary heat source. I have put the heater part on a t-stat in the past.
    Okay I will concede that it could be considered space heating, then you would have to reconcile the following statement with 424.3(B).

    Quote Originally Posted by Dennis Alwon View Post
    In general the heat is required to be 125% but not the light & fan. All that doesn't matter if the manufacturer requires a 20 amp cir anyway and I believe the calc. would still be over 15 amps
    424.3 Branch Circuits.
    (B) Branch-Circuit Sizing. Fixed electric space-heating
    equipment and motors shall be considered continuous load.

    And if the fan and heat are considered continuous, then the light is considered.......?
    "Electricity is really just organized lightning." George Carlin


    Derék

  2. #22
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    what difference does it make cost wise? A few dollars? do what the instructions say and be done with it.
    Bob

  3. #23
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    Quote Originally Posted by petersonra View Post
    what difference does it make cost wise? A few dollars? do what the instructions say and be done with it.
    That was my thought also.

  4. #24
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    Quote Originally Posted by jumper View Post
    IDK, I think that it is more of of an appliance IMO, the heater is only really intended to heat part of the space for a limited amount of time. It is not the primary source of heat for the bathroom.
    Take a look at the scope of 424

    424.1 Scope. This article covers fixed electric equipment used for space heating. For the purpose of this article, heating equipment shall include heating cable, unit heaters, boilers, central systems, or other approved fixed electric space-heating equipment. This article shall not apply to process heating and room air conditioning.
    Notice it says for space heating, not primary or central heating.

  5. #25
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    Art 422 is the general "appliances" section.

    Unless something falls in the following sections 424 - 440 which are for specific appliances, it is covered in 422.

    424.1 Scope.
    This article covers fixed electric equipment used for space heating. For the purpose of this article, heating equipment shall include heating cable, unit heaters, boilers, central systems, or other approved fixed electric space-heating equipment. This article shall not apply to process heating and room air conditioning
    .

    If it heats a space and is not process heating or room air conditioning then 424 applies.

  6. #26
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    Quote Originally Posted by jumper View Post
    Okay I will concede that it could be considered space heating, then you would have to reconcile the following statement with 424.3(B).



    424.3 Branch Circuits.
    (B) Branch-Circuit Sizing. Fixed electric space-heating
    equipment and motors shall be considered continuous load.

    And if the fan and heat are considered continuous, then the light is considered.......?
    I was looking in my 2008 NEC and didn't see the part that said, "and motors". I see it was added in 2011 NEC. I suppose it only makes sense for the motor of a heating unit be considered continuous.

  7. #27
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    Quote Originally Posted by growler View Post
    A fan/light/heater is just a space heater combined with a light and fan. Is there some difference between the heat of a ceiling mount fixture and say a wall mounted space heater?
    Not in my opinion. That's why I say it falls more under the 2008 NEC 424 article.

  8. #28
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    Quote Originally Posted by jumper View Post
    Okay I will concede that it could be considered space heating, then you would have to reconcile the following statement with 424.3(B).



    424.3 Branch Circuits.
    (B) Branch-Circuit Sizing. Fixed electric space-heating
    equipment and motors shall be considered continuous load.

    And if the fan and heat are considered continuous, then the light is considered.......?
    Why would the light be considered continuous. The motor can be considered continuous but the 125% on the heat should cover that. NO?

  9. #29
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    We are really getting into odd territory as the item is a unit with a label so we do not calculate each item separately.

    That said if we were too;

    1) The light could be called continuos or not. It would depend on the use

    2) The exhaust fan motor would be required to be counted at 125% per article 430 if is larger than...

    3) ... The heater blower motor at 100 or 125% dependent on which motor is larger

    4) The heater element at 125% due to article 424


    But why would we do all that? The instructions say 20 amp circuit.

  10. #30
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    Quote Originally Posted by iwire View Post
    We are really getting into odd territory as the item is a unit with a label so we do not calculate each item separately.

    That said if we were too;

    1) The light could be called continuos or not. It would depend on the use

    2) The exhaust fan motor would be required to be counted at 125% per article 430 if is larger than...

    3) ... The heater blower motor at 100 or 125% dependent on which motor is larger

    4) The heater element at 125% due to article 424


    But why would we do all that? The instructions say 20 amp circuit.
    I've been watching this string of posts and comparing the time invested in tryiing to justify a 15a circuit verses just installing a 20a as iwire said and calling it a day.

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