Breakers Tripping When Using A/C & Appliances At Same Time

[tilldee]

Is this natural? Each time I use the microwave or turn on the hair dryer while the A/C is on, the coach breaker will trip. Is there something we can do to prevent this from happening?

[wolfe10]

Couple of "ifs" in this:

If voltage is correct 120 +/- 10%.

If the A/C is functioning properly.

If (probably the biggie) nothing else is on 120 VAC (such as water heater element, charger charging deeply discharged batteries, and to a lesser degree, refrigerator, etc)

THEN it should work with one A/C and one other item like hair dryer or microwave unless a really big one.

But, worse case is turn the A/C back to FAN for the duration of the additional heavy load.

[rossboyer]

We need more information to be able to help you.

When you say the coach breaker trips, which breaker?

Is your service, 30 amp or 50 amp?

Is your coach, 30 amp or 50 amp?

I am guessing the answers will be 30 amp. If so the air conditioner is 12 to 15 amps of load.

The microwave is also 12 to 15 amps of load.

Your converter charging the batteries is 5 to 20 amps of load.

Refrigerator is 3 to 50 amps load. Turn it to gas.

Do you have an electric heating element in your water heater? If you do, turn it off

12+12+5 is 29 amps or 15 + 15 + 20 is 50 amps of load.

Both are too close to 30 amps or much more.

The solution is to turn off a major load to be able to operate another major load.

[kaypsmith]

In addition to mrboyer's comments, you indicated the (coach breaker) tripped. Did you perhaps mean the campground breaker, or is it really one inside the coach? If the one inside the coach that is tripping, then the circuits inside the coach are wrong. Each ac unit should be on an individual breaker.

[wolfe10]

And, if the coach breaker, is it the 30 amp main breaker (which is what I assume) or individual breaker for a particular circuit?

[tbutler]

Well Tilldee, you are just a bundle of electrical questions lately. I just posted a helpful web site on your previous question but it rolled over to page 2 and may go unnoticed so here it is again.

RV Electric

There is a section on RV Recepticles for 30A and another on 50A. There is also a section on testing RV Outlets as in testing an outlet in a park or at a friends house before you plug in. There are designs for home made testers that you can use.

We're still waiting for more information about where the breaker that is tripping is located, in the motor home or on the post outside the motor home. Are you plugged in at a park or at a friends home. If plugged in at a friends home, what kind of service do you have, 20A, 30A or 50A? What kind of cord are you using to plug in. Are you able to measure the voltage when the air conditioner is running? If you have good electrical service it should measure 120 volts without the air conditioner (or other large appliance) running and then when you plug in it should remain really close to that 120 volts. If it drops 10 or 15 volts with the air conditioner running then it will drop further with another appliance running and the result is insufficient voltage which will cause a higher amperage draw and thus trip a breaker that wouldn't normally trip. Yes, I've seen campgrounds with electrical service this poor. We have an electrical readout on the dash of our motor home and one of the first things I check when we are running air conditioners is the voltage when both air conditioners are on.

Another possibility is that the breaker itself may be defective. Breakers do wear out. Replacing the breaker may solve your problem. I've had this done at campgrounds before and had the problem solved that way. A breaker is amazingly cheap. A 30A breaker should be about $5 at Lowe's. A 50A breaker should be about $10. Have the campground replace it. If you are at a friends house, they may have something else running on the 30A circuit but if not, offer to replace their breaker for them and see if that helps.

Give us more information about your motor home and your situation and we may be able to better diagnose your problem.

[kaypsmith]

Tom your reference to RV Electric, is very informative and should be included in all RV manuals, thanks!

[tilldee]

In addition to mrboyer's comments, you indicated the (coach breaker) tripped. Did you perhaps mean the campground breaker, or is it really one inside the coach? If the one inside the coach that is tripping, then the circuits inside the coach are wrong. Each ac unit should be on an individual breaker.

I'm talking about the coach breaker (not the campground breaker). Not the AC breaker either.

We need more information to be able to help you.

When you say the coach breaker trips, which breaker?

Is your service, 30 amp or 50 amp?

Is your coach, 30 amp or 50 amp?

I am guessing the answers will be 30 amp. If so the air conditioner is 12 to 15 amps of load.

The microwave is also 12 to 15 amps of load.

Your converter charging the batteries is 5 to 20 amps of load.

Refrigerator is 3 to 50 amps load. Turn it to gas.

Do you have an electric heating element in your water heater? If you do, turn it off

12+12+5 is 29 amps or 15 + 15 + 20 is 50 amps of load.

Both are too close to 30 amps or much more.

The solution is to turn off a major load to be able to operate another major load.

Service is 30 AMP

Coach is 30 AMP

Fridge is running on AC

Water Heater is LP Gas

And, if the coach breaker, is it the 30 amp main breaker (which is what I assume) or individual breaker for a particular circuit?

The breaker is the 30 AMP main breaker as everything goes off. The AC breaker does not trip.

TButler - Thanks for the site. I will check it out and pass it along to my DH. I was hoping there was something we could do to stop this from happening. We have friends who have a 50AMP coach and run both AC's, we only have one, along with an electric full size fridge and water heater and they do not have this issue.

[kaypsmith]

Think it's time to talk to an electrician about an alternate way to run AC at campground, or some of the other appliances. Could be simple to run a heavy duty extension cord to some of those, and plug into the 20 amp plugin at the campground to take some of the load away from the 30 amp breaker. Also look inside the door of the fridge and check for amp draw, many house type easily pull 10 to 12 amps, and surprisingly the smaller units are usually less efficient than the larger ones. Good luck hunting.

[huffypuff]

You may need to have an intelitek control panel installed. Why? If your coach is 50 amp and you're plugged into 30 amp or worst 20 amp you will be overloading the source of your power. The power management in the intelitek will switch things off if you go over the rating. Example: When I was at Redmond this week my 50 amp coach was plugged into 30 amp. I was running my front A/C and used the microwave while the A/C was running. Guess what, there isn't enough amps for both on one leg since the frig was on 120 as well as HW heater. So the intelitek turned off the a/c until the microwave was done then turn the a/c back on. Are you sure this isn't what's happening?

[tbutler]

Quote: TButler - Thanks for the site. I will check it out and pass it along to my DH. I was hoping there was something we could do to stop this from happening. We have friends who have a 50AMP coach and run both AC's, we only have one, along with an electric full size fridge and water heater and they do not have this issue.

With a 30A coach, you have a single hot line with 30A available. Your friends with a 50A coach, have two hot lines, each capable of carrying 50A. This means that a 50A coach has 100A available when plugged in to a 50A source.

As mentioned by huffypuff, we also have an Intellitec control panel which will automatically adjust the appliances and circuits to keep the amperage below the limit available. When we are on a 50A circuit we can run everything in our coach at one time. On our generator we have two hot lines at 35A so the Intellitec will limit our total usage to less than 70A and not more than 35A on either of the lines. If we are on a 30A supply, the Intellitec knows this because it only senses a single hot line. This results in some appliances being shut down by the automatic system according to the systems programming of priorities for the various systems. This prevents the circuit breaker on the supply line from tripping. If we are on a 20A circuit (normal household circuit), we can manually tell the Intellitec that the circuit is 20A, it has no way of sensing this as a 20A or 30A circuit as both have a single hot line. The Intellitec prevents tripping the breaker on the post almost all the time.

Installing an Intellitec in an existing coach isn't easy. The panel has to have a way to separate different circuits and control them individually. I can't imagine how difficult and expensive it would be to do with an existing coach. The short answer to your problems is that you will have to do the job of the Intellitec by hand, shutting off the air conditioner when you want to use another appliance. It's a juggling act to keep the amperage below 30A.

By the way, any appliance with a heating element, hair dryer, portable heater, coffee maker, water heater, toaster oven, etc. will be a high amperage appliance. If the owners manual for your coach doesn't have a list of appliances and their amperage draw, make a list for yourself. You will find a label with the amperage listed on every appliance. Installed appliances like a microwave might be difficult to find as they may be on the back of the microwave. In that case I would look at the manufacturer name and model and see if the information might be available on the internet and if not, contact the manufacturer of the appliance or your motor home to get the information. You shouldn't have to take the coach apart to get this information. Once you have this information and have used it for a while it will become second nature, you will know which appliances can be run at the same time and which need to be shut off temporarily while another is in use.

Finally, any time an electric motor starts there is an momentary surge in electricity and its amperage draw spikes. This can cause a breaker to trip if it takes the the amperage over the limit of the breaker. Some breakers have a time delay to prevent a temporary spike from tripping them but those aren't in use in RV Parks to my knowledge. The compressor in the air conditioner and the compressor in the refrigerator are two appliances that will cause this temporary spike. If you run your coach on the generator you can actually hear this spike in the tone of the generator when the air conditioner kicks in. The generator will surge up in power and then settle back to a steady running sound.