# Running A/c And Microwave Tripping Breaker



## Greg

We just got our first camper last oct. so we are still learning. I want to know if it is normal for the 30 amp breaker to kick when running a/c and turning microwave on. This happened a couple of times this weekend. there were a few other things running like a fan, tv, and a few lights. It kicked the breaker in the camper twice and the breaker at the campground three times. Just wondering if this is normal or if there could have just been a problem at that campground. A few of the electrical boxes were in need of maint.


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## hautevue

In my TT, the a/c and microwave are on different breakers in the TT Power Panel.

If you are tripping the TT panel breakers, then it's likely that the incoming voltage is low. Lower voltage means the appliance draws more current and if it exceeds the current rating of the breaker, pop goes the breaker.

If you are tripping the campground power post breaker, then you really have a problem and it's up to the campground to fix. My guess is low voltage again, and the campground post breaker is overloaded and it, too, pops.

Check the voltage with your voltmeter (the one you bought for $10 or $20 at Radio Shack







) If the voltage on the meter is under 108 or so, there's your problem.


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## Greg

My a/c and microwave have seperate breakers to, it did'nt trip those breakers it triped the main 30 amp breaker in the camper. I was kind of guessing it was a problem with the camp ground because i think i remember on memorial weekend running the ac and microwave at the same time and none of the breakers kicked.


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## swanny

with 30 amp you sometimes need to pick and choose what to run and what to shut off. If the microwave is running and the ac compressor is running I think you maybe pushing the limits of 30 amp service. The CG power kicking out sounds like a CG issue. JMO

kevin


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## Chuggs

I agree with that.

Here's a very inexpensive clamp meter that you might consider...

http://www.harborfreight.com/digital-clamp-meter-96308.html

If you're handy with household wiring...go to Home Depot and get a 30amp Travel trailer Plug & Receptacle, and three 2 foot sections of 10 gauge wire (BLACK, WHITE, GREEN) (or better yet 8 gauge wire) to make a test jumper. You wouldn't leave this attached while camping...but you can use it to troubleshoot electrical problems. Hook the hot lead up with BLACK wire, the neutral leg with WHITE wire, and the ground leg with GREEN wire.

What you do is plug the adapter into the campground outlet...and your camper into the adapter. You'll have three strands of separated wire running that short distance. You can clamp the meter on your BLACK wire...with the meter set to A/C amps...and read how much current your camper is drawing. This will give you a chance to actually measure the amp draw of different components of your RV. Some clamp meters even have a MAX feature, which holds onto the highest measure...so you can see what the peak draw is when items like the a/c startup...which have a surge when they kick on. If you're up to spending a lot more on a meter...they do make ones that measure DC amps as well as AC amps. This is handy for checking the load on your alternator on your tow vehicle...or seeing how much DC amperage your inverter is drawing (if you have an inverter).

Here's a problem that you might be running into:

You find a nice secluded spot to set up camp. Of no fault of your own...you're probably many feet away from the neareast MAIN electrical panel. SO, the campground ran a long distance of wire from the MAIN panel to your campsite. The further the distance the more resistance. Resistance will cause the line voltage to drop when place under LOAD. It will probably meaure all nice and 110v-115v when there is nothing attached...but hook up that camper...and suddenly the voltage goes down to 109v or less.









To fix this...the campsite needed to run a larger gauge wire...but more gauge is more $$.

If the power pole in your campsite has a 15amp outlet on the same leg as the 30amp outlet...you can put your meter on A/C voltage and put the test leads into the 15amp outlet while your camper is drawing a load on the 30 amp outlet. This will let you see the voltage drop. UGGG!

Here's an example of how voltage drop causes breakers to trip.

Let's say that your breaker is a 30 amp breaker.

30 amps X 110 volts = 3300 watts.

So you should be able to run a continuous load just under 3300 watts.

Now if you have a voltage drop due to the long run of inadequate gauge wire...or maybe you yourself are to blame for using a 50ft extention cord to make it even worse. Now your voltage drops to 107v...

3300 watts / 107 volts = 30.84 amps and POP goes the circuit breaker.

I hope that I made that illustration easy to follow.

If the breaker is popping at less that the rated load...it may be weak and need to be replaced. Most will take momentary surges above the rating without popping. The manufactueres site will have the specs of each circuit breaker usually.

Charlie


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## Chuggs

Oh...one more thing to consider.

A/C units don't always draw the same ammount of amperage. The amperage will depend on how much WORK the unit has to do. The coolant pressure will vary depending on latent heat and the freon charge in the unit. So it might just draw more current on a 97 degree day in the sun...than it will on a 85 degree day in the shade...or you might get a difference in current draw if your unit needs to be charged with freon. It would be interesting to see how meaurable the difference is with a clamp meter...


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## Duanesz

Did you have your water heater on electric too? Some times When I have the a/c running and the hot water heater on electric and run the microwave it will pop the breaker. You just have to be aware of whats on an running. Most of the time I want to use the microwave I turn the water heater off so theres not to much draw you are not always aware that the water heater is calling for heat.


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## ED_RN

Duanesz said:


> Did you have your water heater on electric too? Some times When I have the a/c running and the hot water heater on electric and run the microwave it will pop the breaker. You just have to be aware of whats on an running. Most of the time I want to use the microwave I turn the water heater off so theres not to much draw you are not always aware that the water heater is calling for heat.


That goes for the frig as well. The few times we have camped with power we haven't had a problem. If running on the gen's I have to switch the H2O heater and frig to propane of the gens will kick out because they are overloaded.


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## Greg

Duanesz said:


> Did you have your water heater on electric too? Some times When I have the a/c running and the hot water heater on electric and run the microwave it will pop the breaker. You just have to be aware of whats on an running. Most of the time I want to use the microwave I turn the water heater off so theres not to much draw you are not always aware that the water heater is calling for heat.


 Yes when we get to the campsite i always bleed the air out of the water lines and then turn the eletric water heater on and leave it on for the duration of the stay. I only turn the lp on if we are all taking showers and i want the waterheater to recharge faster. I guess i will just have to start watching how much stuff we run at the same time.


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## jozway

If the water heater, a/c and microwave were all drawing amperage at the same time it would easily trip the breaker. Anytime we use the a/c we limit all the other big amperage draws (water heater and micro).


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## battalionchief3

We have tripped a few times with the AC and the micro running. A toaster is nothing but a controlled short, so watch that running too. Usually it is a low voltage problem. I find it easier to turn the AC off or just run the fan for that short time. Some people get a 50amp adapter and plug there 30amp cord in it. They don't have 50 amps but the connectors in the plug usually are not as worn out as the 30's since most people use the 30's. Loose plugs make heat and drop voltage.


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## Fanatical1

All good advice.

You can not run the AC, microwave and other high draw appliances at the same time.

If you had the electric hot water heater running at the same time that might be the
culprit. Fridge on electric also uses some juice too. Toasters or coffee makers
are a big draw. They will need to be off.

You should be able to run the microwave and AC if your not running the water heater,
toaster,coffee maker ect.... Lights don't use too much but it all adds up.


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## Up State NY Camper

Tripping breakers is very common in tt's. All of the above advice is great, and right on. If my wife is going to be using the hair dryer, or something that draws a lot of amps, I start turning stuff off temporarily until she's done. After all, it is only a camper with 30 amp service. Your house gets almost 10 times that in service.


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## GO WEST

I just had this problem at KOA North in Albuquerque. This camp is well maintained and I am close to the main building so I don't think it's a campground problem (usually).

I had the fridge on elec (use their power, not my gas), elec hot water heater on + the AC and when I turned on the microwave it flipped the 30 amp breaker on the pole outside.

This didn't surprise me at all. I usually remember to just turn off the AC while using the microwave, even if the elec water heater is off. I do the same for a hairdryer, electric skillet, or toaster, just turn off AC for awhile.

But sometimes I forget and flip the breaker, it's normal.


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