Not always but it happens from time to time. A technician visited for this issue and at that time we couldn't reproduce the situation but he observed my coffee machine hit very high ampere like 9 or 11A at the beginning very shortly. but breaker unit can hold 20A. We guessed even though the reader couldn't catch it but it could reach to 20A or nearby threshold point. Anyway, he replaced the break unit with another and said let's see what would happen. Later, I have the same problem one or two times a week again.

Now, I wonder if there is any high current holding outlet so that it prevent high current from flowing in a very short moment?

Or, is this coffee machine problem?

  • Is this a normal breaker or a GFCI/AFCI breaker?
    – JPhi1618
    Nov 2, 2017 at 19:08
  • A standard breaker will not trip instantly. It has a time delay relative to the current being drawn. Depending on the breaker, you can draw multiples of the listed current for seconds before the breaker will trip. A small spike that the meter wasn't fast enough to catch wouldn't trip a standard breaker.
    – JPhi1618
    Nov 2, 2017 at 19:25
  • I checked the breaker and found yellow square D symbol and red test button and on/off switch with "20" only. So, I think it is not a GFCI.
    – Daebarkee
    Nov 2, 2017 at 19:27
  • 2
    If it has a test button, then it would be GFCI. Square D commercial breakers have a clear window that shows red when a breaker is tripped so don't confuse the two. The breaker would probably say "GFCI" or "AFCI" if that's what it is.
    – JPhi1618
    Nov 2, 2017 at 19:39
  • Thank you, @JPhi1618. I decided to move my coffee machine to the other line as Billy C suggested.
    – Daebarkee
    Nov 2, 2017 at 19:43

2 Answers 2


It sounds like there is other equipment on this circuit of which you are unaware. Perhaps your refrigerator? It's a common intermittent load in kitchens that could easily pop a breaker in combination with a coffee maker.

Your electrician should have measured amperage draw inside the electrical panel when he swapped out the breaker.

Invite the electrician back over, for some coffee.

You can use a Watts-Up or Kill-a-Watt meter to measure the coffee maker's draw at the outlet:wattsupkill-a-watt

And the electrician should have an amp clamp to measure at the breaker.

  • Yes, he had the amp clamp and measured on the breaker line on which I connect refrigerator, my coffee machine, and my echo. usually, without coffee machine, it showed 1~2A.
    – Daebarkee
    Nov 2, 2017 at 19:30
  • I wonder if the only solution is to move my coffee machine to the other line which has no device connected. :(
    – Daebarkee
    Nov 2, 2017 at 19:32
  • 1
    Ok. So that's the answer. Fridge and coffee maker shouldn't be sharing circuits. Refrigerators often have several stages of power draw, and can pull quite a lot at their max. If you can't move your coffee machine to another circuit, you'll need to turn off the fridge first. Try that for a couple weeks, and you'll see the problem go away. I could hypothetically imagine using zwave controllers to cut power to your fridge automatically every time the coffee maker goes on. But you'd have to program that, and it could damage the fridge to do that to often. Nov 2, 2017 at 19:36
  • 1
    One last thing just occurred to me that I thought I'd add. You could use the zwave controllers in the opposite order. Set it up so that when the FRIDGE is drawing > 2A, it turns power off to the coffee machine. Most simple coffee machines I've seen should suffer NO damage being controlled like that, though it could make it a nuisance to make coffee in the morning. When I was a kid I had an AC, mini fridge, microwave, and four computers on UPS in my bedroom on a shared 15A circuit. I used X-10 and a VB 6 program to juggle load, and the UPSes were needed to keep the computer running it on. Nov 2, 2017 at 20:19

If the coffee maker's heating coil is cracked, it will fault through the water to ground and trip the breaker as it should.

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