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  • overloaded?

    Hi all,

    I'm new to the forums, so hello. I just bought a new house and am getting started with do-it-yourself projects. I'm new to all of this, so I'm learning as I go...

    Anyway, I just 'mapped' all the circuits in my house, and I am confused about something. One of my kitchen circuits is rated for a mere 20A x 120V (2400 W), yet there's A LOT plugged into it:

    toaster (950 W)
    coffee pot (850 W)
    microwave (1000 W)
    dishwasher (~1000? W)
    garbage disposal (~500? W)
    laundry washing machine (~1500? W)

    These things add to nearly 6000 Watts! Granted, I've only got two or three in use at one time, but just running toaster + microwave + coffee pot (2800 W) during breakfast time should overload the circuit and trip the breaker, right? Yet, I've had no troubles so far. My question is: why hasn't my breaker trippred or my kitchen blown up?

    Thanks very much for input,
    Jeff

  • #2
    what might seem as an overload probably isn't. two outlets may be on a dedicated circuit. only real way would be to get an amprobe. this is a clamp around the conductor, that clamps around a conductor and reads the amps in a circuit. you can get one at home depot or lowes. I have one made by greenlee but mine costs around $150. the Ideal co has one for about $30. Mine is digital, Ideal's is an analog. get one and try it, it may alleviate any questions in your mind.

    Comment


    • #3
      hayzee,

      thanks, but i'm confused (please be patient...i'm new to this). All the appliances I listed above turn off together if I trip the circuit breaker. I assume this means they're all on the same circuit. But sounds like you're saying this is not necessarily true. Can you explain?

      thanks again
      jeff

      Comment


      • #4
        Jeff, you say a "mere" 20A circuit. This is the largest circuit you can install for general receptacles.

        The main thing is not everything is used at the same time. While your particular situation is not currently code legal it was common way back in the day when we had FAR less appliances.

        The reason your kitchen hasn't "blown up" yet is because that simply does not happen. I guess that statement was rhetorical.

        The reason the breaker does not trip often is because breakers do NOT trip the instant the amperage exceeds the rating. They trip on a "curve".
        A 20A breaker will hold for hours at 22 or 23 amps. It will hold indefinitely at 20 amps. It will hold for a few minutes at 25-26 amps. A few seconds at 35 amps.
        This is not to say it is proper for a circuit to be loaded like this, but the code has "cushions" to prevent situations like this from becoming dangerous.


        The reason I say it is not legal is because the washer should be on a dedicated 20A "laundry" circuit isolated to just the laundry area. The DW and disposal should either have a dedicated circuit for each, or they can share a 20A circuit. The micro, IF permanently installed must also be on a dedicated circuit.
        ANY and all counter top appliances are plugged into the "small appliance circuit(s)". The current code requires a minimum of two SA circuits. This has been code for quite some time.

        When was your home built?

        Comment


        • #5
          SP,

          thanks a lot for reply...very helpful.

          By "mere" 20A, I just meant in comparison to the 30A and 50A breakers that are also in there (I think these are all with the 240V circuits). and yeah, the "blown up" comment was just for a smile.

          I think the "cushions" that you describe probably best explain why the breaker hasn't tripped. When I'm running coffee pot, microwave, and toaster at the same time, I guess I'm pushing maybe close to 22-23A, but this isn't occurring for more than minutes at a time. Suffice to say, I'll make sure to limit the number of items running at once in the kitchen!

          House built in 1947. Kitchen circuits definitely not up to code, but we're planning a kitchen/laundry-area remodel, so we'll address these problems then.

          Thanks again!!
          Jeff

          Comment


          • #6
            Originally posted by jemoore View Post
            House built in 1947. Kitchen circuits definitely not up to code, but we're planning a kitchen/laundry-area remodel, so we'll address these problems then.
            You watch and see how many circuits they will be required to run just to meet code.

            Comment


            • #7
              I got to rewire a 1920-something house....It originally had about 3 outlets in the whole house! As stated above- we didn't used to need all this electricity!

              If you want to run multiple appliances all at the same time, I'd consider doing something- running new circuits or redoing the kitchen wiring.

              In the meantime, you might consider using some common sense and rough rules to limiting the appliance use....you are right, the coffee pot, toaster & microwave could be over the limit....just my opinion but two at a time is a personal rule of thumb I use for a 20 A circuit and a HEATING appliance....(crude rule that heating applicances seem to be ~1000 watts and a 20A circuit = ~2000 watts + a safety margin).

              P.S. Your coffeemaker heating element cycles on and off too- so it's not like your coffeemaker, toaster and microwave are continuosly drawing their full current/wattage....but if all three hit at the same time, you might trip a breaker.

              Comment


              • #8
                new code says a minimum of two small appliance branch circuits in the kitchen. within a 6 foot radius of the sink, must be gfci protected. any counter space 24 inches or wider needs a receptacle. in my kitchen I have six circuits for all the counter top receptacles and two for any receptacle at the four foot level on an external wall. fridge is on a dedicated circuit. dishwasher is on a hard wired dedicated circuit.

                Comment


                • #9
                  A few clarifications:
                  - The two SA circuit minimum rule has been in effect for quite some time now.
                  - The 6' from a kitchen sink rule was dropped several code cycles ago. ALL kitchen counter receptacles must be GFI protected.
                  - Any counter space 12" or more requires a receptacle.

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                  • #10
                    Thanks Pete that's what happens when you get old and senile. Knew about the SA for a while but didn't know about the gfci rule.

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                    • #11
                      No prob. I just wanted to make sure we use the latest codes just in case. Not all places adopt the latest codes, but the ones in question are a few cycles old and in most places they are accurate.

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                      • #12
                        maybe I ought to invest a new codebook.

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                        • #13
                          I am assuming your house is older, and at the time it was built had the circuits required by code at the time. If we are talking about the 50's or even 60's, microwaves and Mr. Coffee hadn't even been invented!

                          Circuit breakers are basically time related devices. There will be a curve showing that at lets say 110% of rating, it will trip after 30 minutes. At 125% it will trip in 10 minutes. 150% 1 minute. Etc. I just pulled these numbers out of a hat, not from an actual chart, but the idea is that you could easily run 2 or 3 things for a short time and not trip. That is not ideal, but by design should not cause a fire.

                          Your "fix" is to have one or 2 additional circuits installed.

                          Comment


                          • #14
                            In new houses the microwave gets its own dedicated circuit. then 20 amps on other gfi's , as ussual not all items are on at the same time like you mentioned. DO NOT put a larger breaker in there !! your breaker is there to protect you from plugging all those things in and using them at the same time, or else your wire supplying current can get over heated and cause fire. Different sized wire takes differnet breakers. This is very important.
                            Your best solution is run a seperate line for the microwave as it ussually runs while other things will be being operated. Henc the new code for miccrowave on dedicated line.

                            Best wishes

                            Comment


                            • #15
                              Originally posted by g5inc View Post
                              In new houses the microwave gets its own dedicated circuit.......... Henc the new code for miccrowave on dedicated line..
                              Another point of clarification. The only time this is true, at least according to the NEC, is if the micro is fixed in place. Basically your average OTR (over the range) micro.
                              Counter appliances, including micro's, are NOT required to have dedicated circuits.
                              Of course, if you know exactly where it will go, it is not a bad idea to have a separate circuit there.

                              Comment

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