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    reweb's Avatar
    reweb Posts: 27, Reputation: 1
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    #1

    Mar 3, 2006, 02:04 PM
    Electric Stove + 30 Amp Breaker?
    Hello,

    I am installing a 20" electric stove in a "Granny Unit"... The stove is going where there used to be a dryer. The wiring (for the dryer) is there including a 30 amp breaker. Does a stove of this size need a 50 amp beaker? Or, can I use the existing 30 amp breaker?

    I want it to be safe and work well of course...

    Thanks!
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
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    #2

    Mar 3, 2006, 02:12 PM
    If you could provide the nameplate data would be helpful, since electrical calculations use amperage or wattage. There is no accurate method of determining the load of this range by the dimensions.

    The range will work fine if the all the burners and the oven are not used all at once. The oven and certainly two burners should work fine.

    This unit sounds like a small apartment range, and may very well only need a 30 amp circuit. Please get back with the load data and we can go from there.
    reweb's Avatar
    reweb Posts: 27, Reputation: 1
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    #3

    Mar 3, 2006, 02:19 PM
    Thanks a bunch for the quick help. Here is what I could find on the stove.

    Three Wire 120/240
    120/208 volt
    60 Cycle AC
    Wattage = 8,800

    What do you think?

    Thanks!
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
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    #4

    Mar 3, 2006, 02:25 PM
    Great, thanks for the info.

    8800 watts at 208 volts = 42 Amps total load.

    This range, to operate at 100 %, will need a complete 50 amp rated circuit.

    I am guessing by the 208 volts is that this is a multi-family dwelling. Keep in mind that, in case you are considering doing the work yourself, that only licensed qualified electrician may be required to install the circuit. This is determined by your local city and state laws.
    reweb's Avatar
    reweb Posts: 27, Reputation: 1
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    #5

    Mar 3, 2006, 02:54 PM
    The property is a single family residence. I plan to do the work myself. My house has a main disconnect so I can throw one lever and shut off all of the power to the breaker box.

    The wire is all there from the breaker box to where I want the stove. It is a big fat wire that is about 1 inch thick. This is a 50's house. Unfortunately, I can not read any numbers to tell the exact gauge of the wire. It is the same type of wire that is serving my existing stove that is on a 50 amp breaker. Remember I am adding a second small stove to serve my "granny unit". I am putting the stove in a location that previously had an electric dryer. By the way, I now use a gas dryer so I won't be pulling much more electricity than before?

    There should be no problem with me changing the breaker in the breaker box to 50 amps + changing the outlet in the wall from a 30 amp dryer to a 50 amp stove, right? It looks pretty simple. Do you see any problem with this as long as all power is off while doing the work?

    Thanks again for your help!.
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
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    #6

    Mar 3, 2006, 03:12 PM
    OK most states allow homeowners to do their own electrical work providing they apply for a permit.

    What is a "Granny unit"? Could this also be called a mother-in-law apartment? If so, then this is no longer a single family dwelling.

    Why is the range a 208 volt then? Your voltage should be 120/240 volt? If you do have 240 volt and connect a 208 volt range, the heating elements will not operate at full wattage, and will affect the heat output. Not a huge deal, it will just take longer to cook. No harm will be caused to the elements, again just will add time to cooking.

    Before just replacing the breaker, you need to be absolutely sure of the wire size. Again the dimension is irrelevant. Older cables were much larger thanthose made now because of the insulation You may need to get a wire stripper that has the exact hole for several wire sizes, and each is labeled with the size.

    You will be safe providing the main breaker is off, certainly to replace the outlet, somewhat safe while replacing the breaker. Keep in mind if the main breaker is in the panel, the wires feeding the breaker are live.

    Again please check the wire size, if it is not #6 copper wire, then you must replace the cable.
    reweb's Avatar
    reweb Posts: 27, Reputation: 1
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    #7

    Mar 3, 2006, 03:45 PM
    I will check the wire size.

    I have no idea why the stove is 208 volt. I will need to check into that.

    Thanks again for your help I really appreciate it!
    toddbailey's Avatar
    toddbailey Posts: 25, Reputation: 1
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    #8

    Jul 20, 2009, 06:47 PM
    Quote Originally Posted by tkrussell View Post
    OK most states allow homeowners to do their own electrical work providing they apply for a permit.

    What is a "Granny unit"? Could this also be called a mother-in-law apartment? If so, then this is no longer a single family dwelling.

    Why is the range a 208 volt then? Your voltage should be 120/240 volt? If you do have 240 volt and connect a 208 volt range, the heating elements will not operate at full wattage, and will affect the heat output. Not a huge deal, it will just take longer to cook. No harm will be caused to the elements, again just will add time to cooking.

    Before just replacing the breaker, you need to be absolutely sure of the wire size. Again the dimension is irrelevant. Older cables were much larger thanthose made now because of the insulation You may need to get a wire stripper that has the exact hole for several wire sizes, and each is labeled with the size.

    You will be safe providing the main breaker is off, certainly to replace the outlet, somewhat safe while replacing the breaker. Keep in mind if the main breaker is in the panel, the wires feeding the breaker are live.

    Again please check the wire size, if it is not #6 copper wire, then you must replace the cable.

    Actually if you connect a 208 volt appliance to a 240 volt supply, you are exceeding it's design specs, thus you'll be driving the heating elements harder and will shorten their life span. I suspect they thought a 208 supply and a 240 volt applience.
    dwm67's Avatar
    dwm67 Posts: 1, Reputation: 1
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    #9

    Dec 11, 2012, 11:12 AM
    Hi I plan on using a 30" Electric Range is a 30 amp breaker with 10/2 wire.. is it Safe to use...
    toddbailey's Avatar
    toddbailey Posts: 25, Reputation: 1
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    #10

    Dec 11, 2012, 11:38 AM
    I doubt the home has 208 volts, 208 is used in split phase wiring. A typical home and residential appliances are rated for 120 and 240 single phase.
    Getting back to the question, a 30 amp breaker can be paired with #10 wiring, but and you'll need to consult the manufacturer on this the unit probably needs a 40 amp service and #8 wiring, at aminimum, just like my 30" ge rangeoven.
    toddbailey's Avatar
    toddbailey Posts: 25, Reputation: 1
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    #11

    Dec 11, 2012, 11:40 AM
    Quote Originally Posted by dwm67 View Post
    hi I plan on using a 30" Electric Range is a 30 amp breaker with 10/2 wire ..is it Safe to use ...
    NO, 40 amp service and #8 wire
    hfcarson's Avatar
    hfcarson Posts: 1,003, Reputation: 49
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    #12

    Dec 11, 2012, 01:01 PM
    Please don't guess... the installation instructions will clearly spell out what size circuit breaker to be used and in many cases also specify the required wire sizes...
    The electrical code requires that all electrical appliances, devices, etc. shall be installed in accordance with their "listing and labeling", so please read the instructions or "google" a copy from the manufacturer.
    toddbailey's Avatar
    toddbailey Posts: 25, Reputation: 1
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    #13

    Dec 11, 2012, 01:30 PM
    40 amp service & #8 is not a guess, it's clearly stated in the nec handbook.
    However, you need to take the device ratings into consideration.
    If the device requires a 30 amp service an existing 40 amp service will work however a 30 amp service will not work for a device that requires a 40 amp service.

    For example: my old GE range has a rating of 11 kw at 240, so doing the math, it requires 45 amp.
    Oddly the manual implies a 40 amp service.. go figure
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
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    #14

    Dec 11, 2012, 03:35 PM
    Dwm67, the nameplate nor instructions may not tell you what size circuit is allowed, as most direct the installer to the NEC.

    Per the NEC:
    For ranges of 8-3⁄4 kW or more rating, the minimum branch-circuit rating shall be 40 amperes.
    Tell us what the wattage, kilowatts, or kW, is of your unit, found on the nameplate, and we can go from there.
    toddbailey's Avatar
    toddbailey Posts: 25, Reputation: 1
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    #15

    Dec 11, 2012, 03:49 PM
    Quote Originally Posted by tkrussell View Post
    Dwm67, the nameplate nor instructions may not tell you what size circuit is allowed, as most direct the installer to the NEC.

    Per the NEC:


    Tell us what the wattage, kilowatts, or kW, is of your unit, found on the nameplate, and we can go from there.

    I rest my case... 40 amp and #8
    stanfortyman's Avatar
    stanfortyman Posts: 5,598, Reputation: 279
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    #16

    Dec 11, 2012, 04:25 PM
    I rest my case... 40 amp and #8
    How in the hell can you rest your case?? All you know is that he wants to wire a 30" Electric Range. Where do you see what the unit draws? What if it is dual fuel? What if it is actually just a cooktop?

    I get your point, and most full size ranges do require a 40A circuit minimum, but we know nothing about this unit except that it is 30" wide.
    toddbailey's Avatar
    toddbailey Posts: 25, Reputation: 1
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    #17

    Dec 11, 2012, 04:50 PM
    I'm using your quote For ranges of 8-3⁄4 kW or more rating, the minimum branch-circuit rating shall be 40 amperes.

    This probably covers 90 + % of 30 inch ranges made in the last 25 years.
    Granted more info is needed but a safe guess would be to follow what the nec code states.
    It highly doubtfull that a service of greater than 40 amps would be required, and there is nothing wrong in connecting an applicance that requires less than a 40 amp service to operate. The service rating is determined by the wire size, the length of the branch circuit and the breaker rating. If it's later determined that only a 30 amp service is required, it would be as simple as replacing a 40 amp breaker with a 30 amp breaker. But this is optional. There is nothing wrong with connecting a 30 amp applicance to a 40 amp service branch circuit.

    Assume it just a 4 element cook top, it still is going to fall in the above rating category as each large element will draw aprox 3 to 4 kw and 2 to 3 kw for a small one.
    stanfortyman's Avatar
    stanfortyman Posts: 5,598, Reputation: 279
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    #18

    Dec 11, 2012, 05:41 PM
    Assume it just a 4 element cook top, it still is going to fall in the above rating category as each large element will draw aprox 3 to 4 kw and 2 to 3 kw for a small one.
    Sorry, this is just wrong.
    I have never seen a four element cook top that required more than a 40A circuit, and the vast majority require just a 30A circuit, with some even a 20A circuit.

    The numbers you are quoting for each element are way off.
    toddbailey's Avatar
    toddbailey Posts: 25, Reputation: 1
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    #19

    Dec 11, 2012, 07:53 PM
    Quote Originally Posted by stanfortyman View Post
    Sorry, this is just wrong.
    I have never seen a four element cook top that required more than a 40A circuit, and the vast majority require just a 30A circuit, with some even a 20A circuit.

    The numbers you are quoting for each element are way off.
    My numbers are estimates, based on the 11 kw oven/range I currently have installed.

    But you are missing the point here. Code states to use a 40 amp service for your typical oven range. So why are we even discussing this? Once again, There is nothing wrong with connecting a device to a branch circuit that has a higher rating than the appliance requires.

    Oh and by the way, my estimates aren't that far off, I found replacement elements that consume 1.8 kw for a small dia and 2.6 kw for the larger diam. But this is all way off topic. The original post askes if a 30 amp service will work for their 30in range. Since most "ranges" come in the form of a 4 element stove and a oven combo, Range being the key here, if it were a stove top then it's a diffent story.
    In any event with out knowing the mfg rating's it's safe to reply with the nec dedfault to use a 40amp service.

    Can we drop this subject ?
    hfcarson's Avatar
    hfcarson Posts: 1,003, Reputation: 49
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    #20

    Dec 12, 2012, 05:53 AM
    When installing electrical equipment you "must" comply with NEC Article 110.3(B)... "Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing and labeling."

    As an electrical inspector, when I inspect your project and see a range (for instance) I will ask you for the installation instructions. (See Attachment) if you don't have this information or what you have done does not match the instructions, I can give you a red sticker...

    The range loads shown in table 220.55 are intended for "load calculations" they are not to be used to size branch circuits... again if the work does not comply with manufacturer's installation instructions, you may fail the inspection.

    Many times it is not possible to review the installation instructions for future equipment so installing the largest branch circuit cabling likely can be a good idea. The circuit breaker size and plug configuration will need to wait for the manufacturer's instructions.
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  1. File Type: pdf Ge Installation Instruc.pdf (34.5 KB, 242 views)

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