Breaker in coach tripping when AC and Electric Hot Water Tank on

[5picker]

I understand all the cautionary statements about current draw but let me give you some real world experience... our last 10 R/Vs have all been 30a and we have successfully run the A/C and water heater (on electric) in every one and never tripped a breaker in all kinds of environmental conditions. Hot, cool, weather, never mattered.

Now, use a coffee pot or hair dryer at the same time and you've got a tripping breaker faster than you can reset it.

[A32Deuce]

Originally Posted by Iwannacamp

I thought they did. I think the “proposed weakening” has to do with running near max capacity and “wearing out” over time.

Cavie will know...

All I know is a friends garage we kept tripping the main breaker trying to get a floor lift to work. A couple years later he told me turning on the shop lights would trip the main breaker. I told him to replace it. He did and no more tripping the breaker. If I'm wrong then that's what I believe!

[A32Deuce]

Originally Posted by 5picker

I understand all the cautionary statements about current draw but let me give you some real world experience... our last 10 R/Vs have all been 30a and we have successfully run the A/C and water heater (on electric) in every one and never tripped a breaker in all kinds of environmental conditions. Hot, cool, weather, never mattered.

Now, use a coffee pot or hair dryer at the same time and you've got a tripping breaker faster than you can reset it.

X2! Ask DW!

[pribbens]

When I purchased our progressive dynamic surge arrestor I also got the remote readout, which reads out the fault, and when operating, the total current. This has proved extremely valuable in determining which items can be turned on together. I use 30 amp as the limit, and have not had to run out to the pedestal to reset that 30 amp breaker--my good luck as I follow this thread.
So yes, as suggested, you can purchase a reasonably inexpensive clamp on meter, some have a peak hold readout. Yet, for continous monitoring, I like what I have.
That said, I wish we had the option to drop out the water heater when the microwave is on, since the water heater can really wait.
I had to dig in on the 80% rule, and I found this from 1996, which, while dated does give some background;
" ...the NEC defines a continuous load as "a load where the maximum current is expected to continue for three hours or more." It's critical for you to understand that this is a load at its maximum current uninterrupted for at least three hours. Office lighting typically meets this qualification.NEC sizing rules. Secs. 210-22(c), 220-3(a), 220-10(b), and 384-16(c) all relate to the sizing rules for overcurrent protective devices (OCPDs). The first three all specify the same requirement:

OCPD size = 100% of noncontinuous load + 125% of continuous load.

Sec. 384-16(c) has the same requirement, except that it's stated in terms of the loading of the OCPD. This rule states that an OCPD can be loaded to only 80% of its rating for continuous loads."

https://www.ecmweb.com/basics/sizing-circuit-breaker

According to this, unless you're running your heat pump, or HVAC 24 7 since it's too cold, or too hot, most RV loads won't make the 3 hour rule for continous. If someone has an update, that would be great to know.

As it's not the pedestal tripping, I would vote for the electric heater intermittantly shorting out against ground, causing the CB to trip. So running on propane is a good troublshooting tip.

On our previous RV and so too on this one, I dug into the wiring of the Heat pump connections and did not like what I saw, so --with power off, course -- reworked those connections located in the ceiling of the MH. Your results may vary.

I've had too many Ground Fault trips, and so replaced the incoming 30 amp receptacle. I found that there too, one of the terminals, (white wire as I recall) was loose, showed signs of overheating, and I was happy to replace and secure these terminals as well. Ground faults were less. I have taken to turning off the converter CB until the power comes on, and this has all but eliminated GF trips.

[rlh1957]

Agree with testing suggestions. Look for any signs of heat or melted wire connections. A loose ground (or load) can cause crazy things under load.

[Grumpy7159]

I did not get the time line of your problem. Was the AC running and then the hot water heater kicked in and one or both breakers tripped? I would check the water heater electrical heating element. It may be faulty drawing more amperage than it is designed to sucking the supply voltage down, causing both the AC and water heater to draw more current, and tripping one or both circuit breakers. Check with an amp probe and voltmeter. A PMT would be better if you had access to one (not many shops have one)

[myredracer]

Originally Posted by Maggot

A 30 amp breaker is not designed to run 30 amps indefinitely. Libert, Square D will verify that. They advised us to keep our loads at 80%.

I will say again, this is incorrect. The time-current graph for an industry standard molded case AC circuit breaker is below and is per UL/CSA and NEC requirements.

In most cases, breaker and wiring for a fixed load (electric heater, lighting, etc.) is required to have a safety margin of 1.25 times the current rating but a breaker itself can and will operate up to it's rating indefinitely as can be seen in the graph. After spending a career in the electrical biz, I am quite familiar with specs, characteristics and code/standard requirements of breakers from all the manufacturers, Square D, Seimens, Westinghouse, FPE and all the rest of them.

A 30 amp RV can be run up to 30 amps continuously with the only caveat being the condition of the pedestal receptacle and shore power plug blades and possible meltdown if there's a poor connection.

[JF Happy Traveler]

Originally Posted by houstonstroker

What voltage are you seeing in your camper? When voltage drops at campgrounds amps go up.

Not sure. I would have to check.

[JF Happy Traveler]

Originally Posted by wmtire

At first thought/glance I figured you were just overloading the main 30 amp circuit by using too many appliances at the same time. However this shouldn't cause the water heater individual circuit breaker to trip (it's usually 15 amps).


If you are getting lower voltage from the pedestal, this does indeed cause the amps to rise, like in a motor..but shouldn't in a heating element. It should actually decrease the amps to the heating element if I'm thinking correct.


I'm thinking there may a problem with the heating element.


Can you turn the water heater to propane operation, and turn off the circuit breaker to the electric heating element and see if this stops the A/C from tripping.

If on propane, breaker does not trip..

[JF Happy Traveler]

Originally Posted by Grumpy7159

I did not get the time line of your problem. Was the AC running and then the hot water heater kicked in and one or both breakers tripped? I would check the water heater electrical heating element. It may be faulty drawing more amperage than it is designed to sucking the supply voltage down, causing both the AC and water heater to draw more current, and tripping one or both circuit breakers. Check with an amp probe and voltmeter. A PMT would be better if you had access to one (not many shops have one)

It trips either way. Doesn’t matter which one is on first.

[wmtire]

Originally Posted by JF Happy Traveler

I have a 2016 Wildwood travel trailer. My breakers trip when the AC and the hot water tank is on at the same time. Sometimes it is the main breaker in the coach and sometimes it is the AC and/or the hot water tank breaker. I believe everything is on its own circuit to my panel. Is it possible that this would trip because I am not getting enough power from the pedestal? The pedestal breaker never trips. Thank you in advance for any help I can get on this.

Originally Posted by JF Happy Traveler

If on propane, breaker does not trip..

OK, I think it's just been assumed by me but should be asked for sure...Are you plugging into a 30 amp or 50 amp outlet.....and are you using any kind of adapter (ie what amp RV do you have)?

[JF Happy Traveler]

Originally Posted by wmtire

OK, I think it's just been assumed by me but should be asked for sure...Are you plugging into a 30 amp or 50 amp outlet.....and are you using any kind of adapter (ie what amp RV do you have)?

30 amp unit and plugging in to 30 amp with no adapter.

[redhooker]

I have only seen 30 amp trailers with electric WH option combined with a 13000 AC. Perhaps yours is equipped with a 15k, which on startup will draw over 15 amps. If the WH is drawing amps as well any other electric item in use would easily push you past 30 amps.

It could be a case of poor option bundling on the part of the ordering dealer. If your unit is relatively new perhaps the dealer could be of assistance.

There are several wattage elements available as well, from around 1400 watts to about 1700 watts. If you have a higher wattage one you may be able to downgrade it to a lower wattage. If your trailer had a prior owner they may even have replaced the original with a bigger one. They are quite inexpensive and easily swapped.

I hope you find a solution as long term stays are definitely made better with the WH on electric.

[JF Happy Traveler]

Originally Posted by redhooker

I have only seen 30 amp trailers with electric WH option combined with a 13000 AC. Perhaps yours is equipped with a 15k, which on startup will draw over 15 amps. If the WH is drawing amps as well any other electric item in use would easily push you past 30 amps.

It could be a case of poor option bundling on the part of the ordering dealer. If your unit is relatively new perhaps the dealer could be of assistance.

There are several wattage elements available as well, from around 1400 watts to about 1700 watts. If you have a higher wattage one you may be able to downgrade it to a lower wattage. If your trailer had a prior owner they may even have replaced the original with a bigger one. They are quite inexpensive and easily swapped.

I hope you find a solution as long term stays are definitely made better with the WH on electric.

You may have nailed it. The original ac was replaced right after we got the new trailer. It was covered under our 1 year factory warranty. I just looked at the invoice and they replaced the 13,500 with a 15k. It sounds like that may be the issue. Too big of a unit for a 30amp coach?

[wmtire]

Originally Posted by JF Happy Traveler

You may have nailed it. The original ac was replaced right after we got the new trailer. It was covered under our 1 year factory warranty. I just looked at the invoice and they replaced the 13,500 with a 15k. It sounds like that may be the issue. Too big of a unit for a 30amp coach?

No, there are plenty of RV's (mine included) with 30 amp and 15K air conditioners. It also should not have anything to do with you tripping the water heaters circuit breaker as you have stated it does sometimes. If you were only tripping the RV's main circuit breaker or the pedestal main, then I would say your cumulative amps are overloading the 30 amps. You also state that it sometimes trips the A/C circuit breaker.(quoted below)

Originally Posted by JF Happy Traveler

I have a 2016 Wildwood travel trailer. My breakers trip when the AC and the hot water tank is on at the same time. Sometimes it is the main breaker in the coach and sometimes it is the AC and/or the hot water tank breaker. .

But now that you added the original A/C was replaced that leads me to think something else.

[wmtire]

Is there any way you can pull the cover off of RV's electrical distribution panel (ONLY AFTER YOU HAVE DISCONNECTED ALL SHORE POWER SOURCES)



If so, can you look at the neutral terminal block (it will be where all the white wires are connected to) like in the left hand side of this pic below. Your actually distribution panel may be different as to the location.




You are looking for a possible loose main neutral wire (the thick one) or possible burnt one.

[CedarCreekWoody]

Have you verified that you do not have a low voltage problem? Check you voltage UNDER LOAD and verify that it is not dropping excessively. If it is check the connections where the incoming power wires connect to the distribution box. Are they clean and connections tight?

Edit: Yeah, what Wmtire said above. He beat me to it. Lol

[wmtire]

One more question. Do you have any kind of inverter and/or a transfer switch in this RV?

[redhooker]

Originally Posted by JF Happy Traveler

You may have nailed it. The original ac was replaced right after we got the new trailer. It was covered under our 1 year factory warranty. I just looked at the invoice and they replaced the 13,500 with a 15k. It sounds like that may be the issue. Too big of a unit for a 30amp coach?

Sounds like a likely culprit. While some people may have had a coach with a 15k and a water heater, they certainly may not have YOUR water heater, which could be one of several different wattages. They also may not have YOUR air conditioner model which may or may not be a heat pump.

I have found there are significant differences in running wattages of different AC models. Dometic rates the 15k Brisk Air II at 1725-1767 (standard vs heat pump) running watts. Coleman Mach 3 15k rates 1400 watts, the Mach 3 PS 15k a staggeringly low 1075 watts.

Each RV can vary quite a bit, so just because one coach has one model 15k and maybe a 1400 watt heater another may have a 1650 watt heater and other loads needing a 13.5k AC. If your air-conditioner was upgraded from what it shipped from the factory with, that would be my suspect number one. If you need the additional cooling capacity like I said earlier you could look into perhaps lowering the wattage of your hot water heater if possible.

[CHEVY67TRK]

I had a similar issue. There was enough room in my breaker box to add another main breaker to split the box.