A/C off of 20 amp service?
Has anyone ever heard of a single a/c unit not being able to start and run on a 20amp shore power circuit? We bought a new coach and the dealer says don't run a/c unless connected to a 30 amp servic...
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dougrainer wrote:Effy wrote:
Yes, I do it all the time. Worst case it will trip a breaker.
Sorry, Worst case is NOT tripping a breaker, but overloading the systems which results in HEAT buildup, which can lead to a FIRE. Your Post is a good example of the misconception of what a 120 breaker REALLY does. A Lot of bad things have happened to people that assume that the 120 breakers stop ALL bad results. I always ask customers, WHY do you think your 30 amp shore cord end is all burnt and pitted? Why is your 30 to 15 amp adapter slightly melted and burnt and pitted? WHY do you think your 50 to 30 Dogbone is Burnt and pitted on the 30 amp end? BECAUSE THEY OVERLOAD THE SYSTEM WHEN NOT CONNECTED TO 50 OR 30 AMP SERVICE. Doug
What Doug said!
The reason the dealer said don't run your AC if you are plugged into 20 amp service is that the AC maxes out that circuit, and ANYTHING else running will overload it, maybe just enough for really bad things to happen. It's true that if you overload any circuit enough, it will trip the breaker. But that is a catastrophic overload. A very tiny minor overload will not trip the breaker, but WILL cook other things, possibly even enough to cause a fire.
And the simple truth is that if you plug the entire rig into that 20 amp circuit, there will be "other things" running whether you know it or not. At the very least, the converter will be charging the battery with at least minimal maintain-charge current. And THAT may be just enough to cause problems.
The takeaway is simple: don't do it. Upgrade your home service to at least 30 amps so you can do it right, and don't risk damage to "things" by using the existing 20 amp circuit.
