(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 15 of 18

Thread: electric heater

Hybrid View

  1. #1
    DIY Senior Member DIY's Avatar
    Join Date
    Dec 2006
    Location
    Florida
    Posts
    150

    Default electric heater

    This heater I have is rated at 1800 watts. Before i plug it In I would like to know if the older wireing system here will be able to handle it (positive and negative wires only in any one outlet). What is the best way to figure for that ? Every outlet in this place is a GFCI (Bdrms.,living room,kitchen and 1 in bathroom) or will this type of outlet trip if to much or not enough juice Is detected at outlet ? Thank you

  2. #2
    DIY Member arfeller's Avatar
    Join Date
    Aug 2007
    Location
    Port Angeles, WA
    Posts
    77

    Default It sounds like it would be close

    Without knowing more about the wireing in the home it is difficult to answer.

    However, somthing that might help is

    Voltage X amps = Watts

    So, Amps = Watts / Voltage

    1800 watts/120 volts =15 amps. Normal household circuits will be 15 amps.

    You would be pulling 100% of the circuits rated capacity if it is a 15 amp breaker with just the heater alone.

    Next you can look at the gauge of the wire. If it is 14 gauge then 15 amp is the max amp allowed.

    12 Gauge could carry a 20 amp circuit.

    I know this does not exactly answer your question but might help

  3. #3
    Homeowner Thatguy's Avatar
    Join Date
    Aug 2008
    Location
    MD
    Posts
    1,460

    Default

    Quote Originally Posted by DIY View Post
    This heater I have is rated at 1800 watts.
    If you have a voltmeter, measure how far the voltage drops when you turn on the heater and post back. A 3vac drop is about normal; that is, from 120vac to 117vac, for example.

  4. #4
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,653

    Default power

    The wire size, circuit breaker, and additional load on the circuit will determine whether you can safely use the heater in that outlet.

  5. #5

    Default

    Just curious...

    What is the brand / model of the heater and what type of plug does it have on it? (Regular outlet plug?)

    Has the plug been changed from the manufacturer's supplied plug?
    Last edited by Billy_Bob; 01-07-2010 at 06:16 AM.

  6. #6
    Electrical Contractor Jim Port's Avatar
    Join Date
    Aug 2009
    Location
    Maryland
    Posts
    156

    Default

    Quote Originally Posted by Thatguy View Post
    If you have a voltmeter, measure how far the voltage drops when you turn on the heater and post back. A 3vac drop is about normal; that is, from 120vac to 117vac, for example.
    How does this help the OP to answer their question?

  7. #7
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,405

    Default

    Basically, that heater will draw close to a full 15A, and if your input voltage drops below 120 (and your normal may be lower than that), it will try to draw more than 15A, so it is very likely it will trip the breaker or blow the fuse fairly quickly. A constant load like that should have some excess capacityon the supply side. I'd be somewhat surprised if it didn't have a 20A plug on it. This has one of the blades turned 90-degrees so it will only fit into a 20A receptacle.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  8. #8
    Electrical Contractor/Instructor jwelectric's Avatar
    Join Date
    Jun 2007
    Location
    North Carolina
    Posts
    2,523

    Default

    This heater will need to be multiplied by 125% or figured at 2250 watts.
    The minimum circuit capacity will need to be 18.75 amps.

    Most 20 amp circuits in a normal house will trip after a couple hours with a heater this large plugged in.

    On any circuit watch for failure of the receptacle that is being used. In most houses all the receptacles are rated for 15 amps and this heater will be drawing the heat of a 18.75 amp load.

  9. #9
    DIY Member arfeller's Avatar
    Join Date
    Aug 2007
    Location
    Port Angeles, WA
    Posts
    77

    Default

    Quote Originally Posted by jwelectric View Post
    This heater will need to be multiplied by 125% or figured at 2250 watts.
    The minimum circuit capacity will need to be 18.75 amps.

    Most 20 amp circuits in a normal house will trip after a couple hours with a heater this large plugged in.

    On any circuit watch for failure of the receptacle that is being used. In most houses all the receptacles are rated for 15 amps and this heater will be drawing the heat of a 18.75 amp load.
    I thought the 125% rule was for calculating sizes for dedicated load circuits like hot water heater.

    Why would a 1800 watt plug in heater be pulling 2250 watt load?

    Also, why would a 20 amp circuit trip from a 18.75 amp load after couple hours? Heat buildup in the panel?

  10. #10
    Homeowner Thatguy's Avatar
    Join Date
    Aug 2008
    Location
    MD
    Posts
    1,460

    Default

    Quote Originally Posted by Jim Port View Post
    How does this help the OP to answer their question?
    It checks connection integrity. Hello again, Mr. Port.

  11. #11
    Electrical Contractor Jim Port's Avatar
    Join Date
    Aug 2009
    Location
    Maryland
    Posts
    156

    Default

    Quote Originally Posted by Thatguy View Post
    It checks connection integrity. Hello again, Mr. Port.
    The question was dealing with circuit capacity, not connection integrity.

  12. #12
    Homeowner Thatguy's Avatar
    Join Date
    Aug 2008
    Location
    MD
    Posts
    1,460

    Default

    Quote Originally Posted by Jim Port View Post
    The question was dealing with circuit capacity, not connection integrity.
    Connection integrity affects circuit capacity, in non-obvious ways.

    Here's a Rorschach-like test for you. For 10 points, referring to my avatar, are you the kid or the snake?
    Explain your answer.
    Last edited by Thatguy; 01-09-2010 at 08:09 AM.

  13. #13
    Electrical Contractor/Instructor jwelectric's Avatar
    Join Date
    Jun 2007
    Location
    North Carolina
    Posts
    2,523

    Default

    Quote Originally Posted by DIY View Post
    This heater I have is rated at 1800 watts. Before i plug it In I would like to know if the older wireing system here will be able to handle it Thank you
    No .

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •