2 a/c units on 1 gen?

afidel wrote:

BB_TX wrote:

valhalla360 wrote:

BB_TX wrote:

valhalla360 wrote:
Probably yes...until the cord melts. As skibine showed, you are probably looking at 27-30amps in ideal conditions. A 30amp is rated for 24amps continuous load.

......

Please show me the specifications that show a 30 amp cord is only rated for 24 amps continuous. I really want to know.

I believe we had this discussion on a different thread. If you want to melt you cords, have at it.

There were statements made that a 30 amp breaker was only good for 24 amps. And that is not true either. NEC specifies a breaker be sized for 125% of the designed max load, or the max load be sized for 80% of the rating of the breaker. Same thing. But a breaker can carry full load for an extended period of time before it trips. If you look at breaker trip curves you will see the initial trip point will be in excess of the breaker amp rating. Not less than rating. Some time delay at small amounts over rating and faster trip as current increases over rating. And yes, breakers can trip at loads slightly below rating due to heat buildup over time, especially where multiple breakers are installed side by side sharing heat.

Properly designed wire sizing must be large enough to carry the full rating of the protection device safely whether it be a breaker or fuse. So with all these statements made I am simply asking for some specifications that state a power cord is only good for 80% of the specified rating. Simple request. I have searched and can not find anything that states a power cord or extension cord can only carry 80% of stated load without burning up.

And I have run my 50 amp trailer on 30 amp service at near max for days (even tripped the park 30 amp breaker a few times) and have never burned my power cord or adapter.

Marinco 30 amp cord

NEC says outlets and wiring shall be derated to 80% for continuous load and that breakers shall be designed to enforce that. If you were using a 50A cord on a 30A plug then duh you'd trip the breaker before your cord melts as your cord isn't the weak point, that's the outlet and the wiring behind it, that's what the breaker's thermal trip is protecting. The time period for continuous is 3 hours at the 80% threshold or above.

Sorry, but I don't use a 50 amp cord on 30 amp service. I use a 25' Marinco 30 amp power cord with a 50 amp connector on the trailer end and a 30 amp plug at the shore power end instead of my 50 amp cord with a 50/30 dogbone.