50 amp Class A plugging into 30 Amps

[jondrew55]

I have a 2014 Class A with a daily modern power monitoring system. It knows when I'm plugged in using a dog one and says 30 Amps. So what won't I be able to run? Will both ACs run? Have not had an opportunity to try it yet

[mmartin]

1 A/C and a few other things.....i wouldn't try the microwave and a toaster at the same time.

[Skip426]

No; do not attempt to run both A/C units.
Dual A/C's was the reason that RV's went to 50 amps in the first place.
The dog bone , splits the 30 amp to two 15amp legs.
The A/Cs , might run , BUT the dog bone WILL overheat, and melt.
Some will tell you that the park circuit breaker will trip before the wiring melts, BUT , I've watched it happen, to a neighbor , who wouldn't believe me.

[JJH3rd]

Use your experience of popping circuit breakers at home as a guide. Here's the science: you are dealing with 120v at 30 amps and Power in Watts = I x E [30*120] = 3600 watts.

So total up the maximum (surge) watts used by each device: AC + refrigerator + the lights and when you exceed 3600 stop and subtract devices until you get back under 3600.

[BFlinn181]

You probably won't be able to run both A/C units on 30 amps. You should check the amperage requirements of each large draw item in your RV and do the math. If you know an appliance's watts, the formula is A = W / V. Also remember your converter/charger and refrigerator are drawing power and A/C units draw more power, especially at start up.

A 50 amp RV service is actually capable of delivering 100 amps of power, 50 amps on each leg. (12,000 watts) 30 amp service is only giving 3,600 watts, only about one third of the 50 amp system!

[jondrew55]

Both ACs seem to be running fine. I won't turn the electric water heater on though. This may force me to read the manuals :/

[Skip426]

Originally Posted by jondrew

Both ACs seem to be running fine. I won't turn the electric water heater on though. This may force me to read the manuals :/

If you really want to scare yourself, go and pick up the connections at the dog bone after the A/Cs have been running.

[D Lindy]

When Both of my AC's are running I'm pulling about 28AMPS. As to running other items when 1 AC is on, I leave my inverter on, and say I have the AC, coffee pot, and microwave on and I go over 30AMPS the Inverter picks up the over Amperage when on a 30AMP service.

[dengraham]

As stated above a 50 Amp motor home will normally have two legs and each leg will have a circuit for 50 Amps (for a total of 100 Amps). A 30 Amp post only can provide a total of 30 Amps. (Note: the 50 Amp post is providing TWO lines (legs) with 50 Amp each). So, one more time, on a dog bone you will have a TOTAL of 30 Amps. The dog bone connects the two motorhome legs together and provides a total of 30 Amps. (It does not split them 15/15; it provides 30 Amps TOTAL. You can use 25 on one line and 5 on the other but you cannot go over 30 Amps).
So, two a/c's typically use 12-15 Amps and you can run both. However, if you are running your satellite receiver, your sound system, your TV, your pc, refrigerator, etc. you are probably going to blow a fuse. You will need to turn off one of the a/c's in order to run the microwave, hair dryer, or electric hot water tank. Some motorhomes have systems to automatically turn certain things off to prevent you from overloading your available Amps. I hope this helps.
>> Dennis

[garbonz]

Originally Posted by Skip426

No; do not attempt to run both A/C units.
Dual A/C's was the reason that RV's went to 50 amps in the first place.
The dog bone , splits the 30 amp to two 15amp legs.
The A/Cs , might run , BUT the dog bone WILL overheat, and melt.
Some will tell you that the park circuit breaker will trip before the wiring melts, BUT , I've watched it happen, to a neighbor , who wouldn't believe me.

Are you sure on the dogbone? If that was true, then NO AC's would work. I think it split the wire and feeds 30 amps BOTH legs. And electricians out there?

[Spk64]

Yes, that is correct 30 amps is available from either leg but not 30 amps from both legs at the same time.
Total is 30 amps regardless of how it is split.
But this is no where near the same as a 50 amp setup which is true 50 amps on each leg.
30 amp = 3600 watts
50 amp = 12,000 watts

[garbonz]

Thanks for the clarification. The 15 amp thing had me confuded

[shiggs68]

If your power monitor panel is an Energy Management System, yes you can run both air conditioners and anything else you want. The system will manage keeping your current below the 30amp limit by cycling everything as you use it.

There should be lights telling you what is being shed to hold the limit.


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TravellingRVDoctor, LLC

[CLIFFTALL]

Originally Posted by shiggs68

If your power monitor panel is an Energy Management System, yes you can run both air conditioners and anything else you want. The system will manage keeping your current below the 30amp limit by cycling everything as you use it.

There should be lights telling you what is being shed to hold the limit.


Sent from my iPad using iRV2 - RV Forum
TravellingRVDoctor, LLC

True. I did with both of my MH's.