Wiring Second Air Conditioner

[steveandbernie]

Hi,

I have a motor home with a 35 A service and 2 air conditioners.  As currently set up I can only run one unit at a time with a switch in the bedroom to change from the front to the back.  I would like to wire the back unit separately.  I have a few questions:

1 I plan to install a separate breaker box for the second AC with a 30 A breaker.  Is that sufficient / overkill?
2 my site has a 50 A outlet only - What do I use to power?  (Is there such a thing as a 50 A chord that will accept 2 - 30 A chords?
3 When my generator is running both AC units are operational - What do I do to ensure that I have isolated the back unit from the generator so there is no risk of a cord being live when the generator is running?
4 Should I pay the $400.00 to an electrician to make these changes for me?

Thanks
Steve

 

[Gary RV_Wizard]

Your RV has 30A service, not 35.

A 20A breaker and 12 gauge wire is sufficient for the second AC power line.

You can wire an adapter to feed to 30A (or a 30 and a 20) from one 50A outlet. I don't know anywhere to buy one - you will have to make it. It's not difficult - we can explain how.

Your rear ac is apparently already wired direct to the generator and I assume you would want to keep it that way. You should add a double pole, double throw switch in the line from the generator to the rear ac and bring the external (shore power) 20A feed into that switch. en you can switch the rear ac power source between generator and 2nd shore power line.

Hiring an electrician depends on your familiarity with things electric. What you are talking about is more complicated than installing a new outlet, but not rocket science either. On the other hand, you are messing with something that could kill you if you get it wrong

 

[steveandbernie]

HI Gary,

Thanks a lot.  I wired the rear air this weekend and have it up and working before the 100+ temps we expect this week in Phoenix.

My switch was pretty straight forward, mostly had to figure out which wire went where.  It was marked on the back of the switch, but I used a proximity AC sensor to see which wires were hot when.  Happily the Generator was wired through the same switch so I don't have to worry about that.

I used an AC outdoor fused box and mounted that inside where the power cord(s) are stored.  That was the cheapest option at about $10.  I did soon find out that one needs a heavy duty - slow blow fuse to handle the powering up.

Regards
Steve

 

[Gary RV_Wizard]

Glad to hear you got it up and running. Good work!