AC without pre-wire?

[FunnyCamper]

we have a toyhauler and the garage has 2 air vents but is still hotter back there. this will be daughters room.

We have 2 AC units. master and center ac. but we have a fantastic fan in the garage. It is not pre-wired to accept an ac unit BUT can I still have one put in it? have the service guys run the necessary wires and get a 3rd ac back there?

I was searching the net for info but haven't found anything helpful to me and knew someone here would have an answer.

thanks for any help.

[FunnyCamper]

yes I agree.

also I know that some good placed fans can help get some air back there so no one suffers too much 🙂

[CA_Traveler]

FunnyCamper wrote:
wow. good electrical info for me.


our state parks are mostly 30 amp pedestal with a 15 amp plug included on the stand. I was hoping to plug into the 30 amp and run just one of my main ac and then the separate garage I would run into the 15 amp plug. that is when the service guy said don't do that 🙂 only a 20 amp plug will be good enough for that 13.5 ac in the garage.

I will check each of my state parks I love and ask exactly what power is on that pedestal. I know the 30 amp plug is there, but will ask what the amps are on the smaller plug. hopefully 20 amp would be sweet to hear is included.

In all cases a DVM is your friend as you want good voltage for ACs and especially when you use both plugs on the pedestal. I'm always suspicious that a 30/20 pedestal is wired for 30A and not a 50A draw.

Don't be surprised if the park doesn't know what the plug is or gives you the wrong answer. The term 15A or 20A is often used to mean the same thing.

BTW If you're at a nice beach site and it's hot have DD come in the front which solves the problem.

[FunnyCamper]

wow. good electrical info for me.


our state parks are mostly 30 amp pedestal with a 15 amp plug included on the stand. I was hoping to plug into the 30 amp and run just one of my main ac and then the separate garage I would run into the 15 amp plug. that is when the service guy said don't do that 🙂 only a 20 amp plug will be good enough for that 13.5 ac in the garage.

I will check each of my state parks I love and ask exactly what power is on that pedestal. I know the 30 amp plug is there, but will ask what the amps are on the smaller plug. hopefully 20 amp would be sweet to hear is included.

[CA_Traveler]

SpencerRB wrote:
Maybe I'm mistaken regarding the load management feature on the triple A/C trailers. Maybe it is only used when attempting to run multiple A/C's off the genny, but if my memory serves me correctly, I've read some people having issues running all 3 at the same time when plugged into 50 amp service.

3 ACs will not trip the CB on 50A unless they are wired on the same leg which would not be the best balance of loads.

2 ACs on one leg combined with other loads could draw more than 50A and trip the CB. Like 2 ACs, HW, hair dryer, MW or whatever.

[allcool]

Sorry, my confusion, didn't realize the subject was a campground 50 amp service.

[CA_Traveler]

allcool wrote:

SpencerRB wrote:

I believe he has 50 amp on the trailer. He was adding a 20 or 30amp separate circuit for the 3rd A/C separate from the trailer electrical.

You do bring up an interesting point. From my understanding, 50amp service is actually rated at 240v, so at 120v, it is rated at 100amps. If this is the case, why do 50amp trailers need load management devices to handle 45 amps (3 15k) of A/C units? This should be less than half of total capacity.

Not exactly...
Its 25amps at 240v and 50amp at 120v.
100amps at 120v would be 12,000 watts, not happening on a Onan5500, ever.

If you measure between both legs of 120v it will be 240v on the 5500 genny. Either 240v leg measured to neutral or ground, gives 120v.
Thats why there are 2, 30 amp breakers, one for each 120v leg of the 240 being produced by the genset. Each leg is good for a little less than 25amps @120v, more or less. So thats how it gets a rating of 50amps, 2 separate 25amp 120v circuits. Actual specs, its 45.8 amps, so in reality, each 120v leg is rated for 22.9amps constant draw...

Make no mistake, 5500 watts is 5500 watts, no matter what voltage. 5500w, thats all we get out of the Onan 5500. Although a surge to 6000watts momentarily will happen.

Let's clear up the confusion: A 50A RV circuit is 240/120V 50A and the 50A rating applies to 240V. This 4 wire circuit can supply 240V @50A or 120V @ 50A on each hot leg or any combination of 240V and 120V as long as the current on each hot legs does not exceed 50A. Few RVs use 240V so we tend to think of it as 2 circuits of 50A each. And the CB is a dual 50A CB. So 50x240=2*50*120=12K Watts available on this circuit.

Don't know how we got into gens but generally you don't get 240/120V from an Onan under 10K watts. Instead they are 2 120V circuits.

[SpencerRB]

allcool wrote:

SpencerRB wrote:

I believe he has 50 amp on the trailer. He was adding a 20 or 30amp separate circuit for the 3rd A/C separate from the trailer electrical.

You do bring up an interesting point. From my understanding, 50amp service is actually rated at 240v, so at 120v, it is rated at 100amps. If this is the case, why do 50amp trailers need load management devices to handle 45 amps (3 15k) of A/C units? This should be less than half of total capacity.

Not exactly...
Its 25amps at 240v and 50amp at 120v.
100amps at 120v would be 12,000 watts, not happening on a Onan5500, ever.

If you measure between both legs of 120v it will be 240v on the 5500 genny. Either 240v leg measured to neutral or ground, gives 120v.
Thats why there are 2, 30 amp breakers, one for each 120v leg of the 240 being produced by the genset. Each leg is good for a little less than 25amps @120v, more or less. So thats how it gets a rating of 50amps, 2 separate 25amp 120v circuits. Actual specs, its 45.8 amps...

Make no mistake, 5500 watts is 5500 watts, no matter what voltage. 5500w, thats all we get out of the Onan 5500. Although a surge to 6000watts momentarily will happen.

I'm aware that an Onan 5500 produces 5500 watts, but no one mentioned a generator.

I'm referring to your standard 4 wire 50 amp 'plug in' service. http://www.myrv.us/electric/Pg/50amp_Service.htm

Maybe I'm mistaken regarding the load management feature on the triple A/C trailers. Maybe it is only used when attempting to run multiple A/C's off the genny, but if my memory serves me correctly, I've read some people having issues running all 3 at the same time when plugged into 50 amp service.

[allcool]

SpencerRB wrote:

I believe he has 50 amp on the trailer. He was adding a 20 or 30amp separate circuit for the 3rd A/C separate from the trailer electrical.

You do bring up an interesting point. From my understanding, 50amp service is actually rated at 240v, so at 120v, it is rated at 100amps. If this is the case, why do 50amp trailers need load management devices to handle 45 amps (3 15k) of A/C units? This should be less than half of total capacity.

Not exactly...
Its 25amps at 240v and 50amp at 120v.
100amps at 120v would be 12,000 watts, not happening on a Onan5500, ever.

If you measure between both legs of 120v it will be 240v on the 5500 genny. Either 240v leg measured to neutral or ground, gives 120v.
Thats why there are 2, 30 amp breakers, one for each 120v leg of the 240 being produced by the genset. Each leg is good for a little less than 25amps @120v, more or less. So thats how it gets a rating of 50amps, 2 separate 25amp 120v circuits. Actual specs, its 45.8 amps, so in reality, each 120v leg is rated for 22.9amps constant draw...

Make no mistake, 5500 watts is 5500 watts, no matter what voltage. 5500w, thats all we get out of the Onan 5500. Although a surge to 6000watts momentarily will happen.

[CA_Traveler]

OP One technique is to route the 3rd AC wiring to a male and female plug in a storage compartment and then continue on to the 20A RV panel CB. Now use a heavy construction cord (10 ga) to connect the AC to a 20A pedestal plug when 50A is not available. This is a common technique and there are posts on this mostly for a 30A rig with 2 ACs.

However a 30A and 20A pedestal may/may not be wired to handle a 50A load. You should be monitoring to monitoring the voltage to be sure a pedestal is OK. Another pedestal in the same CG that is closer to the CG could also be helpful.

I added a second circuit for ceramic heaters when we're on a 30A pedestal. By default it's plugged into a dedicated 20A RV circuit. But when cold it gets plugged into an available 20A plug.

The dealer is right about a 15A plug. However many pedestals have a dedicated 20A plug.

Lots of fun. :B

[CA_Traveler]

SpencerRB wrote:
I believe he has 50 amp on the trailer. He was adding a 20 or 30amp separate circuit for the 3rd A/C separate from the trailer electrical. Thanks

You do bring up an interesting point. From my understanding, 50amp service is actually rated at 240v, so at 120v, it is rated at 100amps. If this is the case, why do 50amp trailers need load management devices to handle 45 amps (3 15k) of A/C units? This should be less than half of total capacity.It's a 240/120V circuit and since few RVs have 240V appliances most think of it as 2 50A circuits. That's a lot of power and will run everything including 3 ACs. For this load management is not needed.

But load management does play a part for 20A and 30A pedestals and the gen.

[SpencerRB]

CA Traveler wrote:
Have you considered upgrading to a 50A service? Then you could run all 3 ACs and the MW, HW and hair dryer all at the same time. Of course you would need a 50A site.

There are various ways to accomplish this.

Another option is a 50A to 2 30A plugs, one for the current plug and the second one for everything the daughter needs.

I believe he has 50 amp on the trailer. He was adding a 20 or 30amp separate circuit for the 3rd A/C separate from the trailer electrical.

You do bring up an interesting point. From my understanding, 50amp service is actually rated at 240v, so at 120v, it is rated at 100amps. If this is the case, why do 50amp trailers need load management devices to handle 45 amps (3 15k) of A/C units? This should be less than half of total capacity.

[CA_Traveler]

Have you considered upgrading to a 50A service? Then you could run all 3 ACs and the MW, HW and hair dryer all at the same time. Of course you would need a 50A site.

There are various ways to accomplish this.

Another option is a 50A to 2 30A plugs, one for the current plug and the second one for everything the daughter needs.

[FunnyCamper]

OK---learned a few things today at the dealer.

He said NO to plugging in the extra AC we are putting into the garage area, a 13K AC directly into a 15 amp. (using that converter 30/15 connector) He said the lowest is a 20 amp. he said I will ruin the ac long term and probably trip the 15 amp alot because of the 'big draw' of amps when it kicks on to cool. He said don't do it 🙂 He said the kick on will be like 15-17 amps at least so best to go no lower than a 20 amp service.

hmmm he said I could try it but not to expect much and would limit the longevity of the ac in the end.

[FunnyCamper]

that is confusing to me 🙂 but I will show hubby your post.

all considerations are good to learn. thanks