Can you tell me approximately how many amps a small microwave oven uses. I rent and my house has 15 amp circuits and my microwave keep tripping the circuit. My landlady told me my microwave uses too many amps. Can that be? Thanks so much for your help

Just text my brother about this question (he is an electrician) he said it's possible the microwave oven is to big in power - but it's most likey the microwave oven has outlived it's life expectancy - in other words it's knackered and you need to get a new one.

Hope this helps :)

If volt * amp = watts perhaps you can take the wattage of your oven and divide by your voltage at home (120 in North America) to get amps.
http://science.howstuffworks.com/question501.htm

Most larger microwaves will draw about 12 amps. Yours should have a decal giving the power it draws inside the door or on the back. If in watts, divide by 120 for the amps. You want the power it uses, not the output. Most microwaves alone shouldn't trip a 15 amp breaker, but if most of your kitchen is on the same circuit, you will have the breaker tripping. Many apartments, especially older ones, have marginal electrical service. Even many houses don't have the service they need in the kitchen. Check the book that came with it. Chances are, it will say it should have its own 15 amp circuit. Adding new circuits is a pain even if they tack up surface mounted wiring. It is possible the circuit used #12 wire originally, and the 15 amp breaker could be replaced with an 20 amp one.

Didn't see Karma's post, before my original, but he is right, 120 is only correct if that is what your voltage is.

Most new construction provides a dedicated 20 amp receptacle for the microwave. Or at most I will share this circuit with a gas range. (since the micro is often located above the cooktop.)

Hi,
Sometimes, if the same wiring is to different receptables in the kitchen, one cannot run many things at one time.
Such as, running the toaster, blender, and microwave all at once might trip the circuit breaker.
When running your microwave, do you have other electrical appliances on as well? The 15 amp breaker should be enough to handle the microwave.

No, I don't run other applicances at the same time. I'm very careful because the circuit keeps tripping. Its only a small microwave. Maybe there is something wrong with the microwave. It seems to trip if I use it a second time to heat up a 2nd dish right after the first time. What do you think? Thanks for your help

Try it on another circuit, even in the bedroom or something. Sometimes a circuit breaker can get old and trip when it shouldn't. This would be more likely to be true if a previous tenant abused it by using the microwave and other stuff like the toaster at the same time. If it is OK, the circuit breaker is bad. Not that bad of a job to change, but it does mean exposing the hot main incoming power, not a good place to start DIY.

If it kicks that breaker off too, time to look for a new microwave. Be sure and have something in it when you test it.

They just changed the switch yesterday so we will see if it keeps tripping. If it does then I'll get a new micorowave. This one is about 6 years old so it may be that. Thanks again for your help and advice. I'll let you know how I make out with it.

Anytime. Glad I could be of some help!

I was quite surprised to find my 1000 watt rated microwave actually used between 1800 and 1860 watts during its high power cooking. It also used 15.8 amps during operation. How did I find this out? Edmund Scientific carries a device called "Kill a Watt" (about $36) which you can plug into any 110v device to monitor power consumption during operation. I was shocked at where my energy was being wasted after monitoring several devices --I certainly never expected a microwave to use as much as it does. The microwave is only 3 months old, so I know it's not outdated or worn out and it's on a dedicated breaker with no other appliances attached. Just thought I'd share this tidbit, and the math does work out 1860 watts, divided by 120 volts is around 15.8 amps!

In addition to all these fine answers ~ if your refrigerator is on the same circuit, then the microwave may work find until the fridge cycles 'ON'. Now both are drawing current and can trip the breaker.