A/C unit

[RMcNeal]

Yeah. I've checked ours and it seems ok. I may use some PVC pipe to keep the ducts open. Looks like I could probably fit 1 1/2" or 2" pipe in the duct work.

[John Shasky]

What did they use to prop it up with?

[eZAK]

Thanks for all your replies!
To clear up any confusion; We do have two Coleman units. Having two A/C units is new to us so bear with me.
After setting the rig up in a new spot, What is the procedure for cooling it down as quick as possible?
Assuming I'll need both units cranked up and 50A at the pedestal, OR can I get away with a wye? (50 > 30 & 20)

Is the duct work connected between both units or only to the rear unit?

I'll also assume that the BTU's are the same for both and that they'll draw the same amperage, correct?

And before anyone says "go check your rig" The HC is back at the dealer for some minor problems.

[RMcNeal]

eZak, ours is a Montana Legacy 3791RD, not a High Country, so YMMV. We have the Dometic units and the duct work runs the length of the rig and both A/C units are connected to it. Normally, I would say you need 50 amp service to run both A/C's but you may be able to get by with 30 amp if you are very conservative with other electrical usage. Never tried it, honestly. Both of ours are 15K btu units, the only difference is the rear unit also has a heat pump. I have the wye cable you are talking about 50 -> 30/20 amp. It works well unless the 20 amp plug is a GFCI at the pedestal. In my experience, the GFCI keeps tripping when using this adapter. I didn't realize when I ordered it, but it says something about that on the packaging.
I also made my own 50 -> 2@30 amp plugs, but only 1 park we go to has 2 30 amp outlets in the same box. Never seen that anywhere else.
I have heard of some units that have a 15K unit and a 13.5k unit, so you could have differing draws, just depends on what was installed in your unit when built.

[RMcNeal]

Oh. To answer the part about cooling down as fast as possible...
What we usually do is get both A/C's running as quickly as possible. If it's really hot inside, I will turn on both fantastic fans to draw some of the hot air out of the rig for about 5 minutes. That seems to be the best help for us.
Also, I recently started blocking the vents under the stairs as it was pointed out that a lot of A/C is being vented to the basement.
Haven't done it yet, but a lot of full timers block off all of the floor vents during the summer too. We have the pull out garage in the back, and 1 floor vent does open directly to that area, so there may be some benefit to that. I haven't bothered as hunting season is approaching, and I'll need the heat more than A/C in a month or so. I have heard some just use cling wrap under the floor vent to block it.

[sourdough]

Originally Posted by eZAK

Thanks for all your replies!
To clear up any confusion; We do have two Coleman units. Having two A/C units is new to us so bear with me.
After setting the rig up in a new spot, What is the procedure for cooling it down as quick as possible?
Assuming I'll need both units cranked up and 50A at the pedestal, OR can I get away with a wye? (50 > 30 & 20)

Is the duct work connected between both units or only to the rear unit?

I'll also assume that the BTU's are the same for both and that they'll draw the same amperage, correct?

And before anyone says "go check your rig" The HC is back at the dealer for some minor problems.

We do pretty much the same as has been described; open it up, turn on both ACs and vents on/open for a short period of time. I will say that we do not "cool down" in 15 minutes or even 30 minutes. It cools off from 120 or so but not cozy cool. Our last trailer was about the same length but not a 5th wheel and cooled down quicker. I attribute that to the additional interior height. If we arrive late somewhere (which I try to never do) we do have the dump feature in the bedroom which DW loves.

If like mine you have a 15k main AC and 13.5 bedroom. They do not draw the same amperage. I do not use a 50/30/20 Y. I only stay in 50A sites. The exception would be in winter when I do not need the ACs. Trying to run both ACs on a 30A wouldn't be a good idea IMO. Too much load and potential for damaging the AC units - sort of like trying to run one off a 15A home circuit.

[RMcNeal]

I have been wondering about running A/C off 30 amp. Some places we would like to go only have 30 amp, which is why I bought the 50->30/20 adapter. My unit has hookups for the washer/dryer. Both are 110 volt, 20 amp circuits. I don't have either yet, but if I did, would I not be able to wash or dry with the A/C running?
Seems counter intuitive. Maybe someone with washer/dryer could chime in please. I have been considering putting in the stackable Splendide units, but no A/C while using them would be a deal breaker.

[RMcNeal]

OK. Just thinking out loud here, so forgive me if this makes no sense. 30 amp gives you a single leg of service at 30 amps. 50 amp gives you 2 legs of of service each at 50 amps, so essentially 100 amps, right. Nothing in the rig runs on 220 volts. So each leg is split independently. With that in mind, there should be enough service to run both A/C's and the washer and dryer simultaneously. Full disclosure, I'm not an electrical engineer but I did stay at a holiday inn express. :-)

[sourdough]

Think of it this way; your 50A service comes in with 2 50A legs split inside your trailer. When you use the 30A it splits the 30A and gives you 2 15A legs where you had 50 with the 50A hookup - HUGE difference.

Now figure that each of your ACs is on each of those 50A legs pulling maybe 15A when starting - no problem. Then you hook up that 30A with 2 15A legs and the AC starts - that circuit is maxed out. Then DW wants to run the washer/dryer with the dryer pulling say 13A....and the AC kicks in; 13A + 15A= 28A you're trying to pull from a 15A supply - pop goes the weasel (breaker). Same will go with toaster, coffee maker, microwave, hairdryer etc. etc.

I would note there is a reason that 30A RVs aren't wired for 2 ACs.

[RMcNeal]

Just what I was thinking, sourdough. Thanks.
I have considered putting a 3rd A/C in and running it on its own 15 amp service, separate from the 50 amp. But honestly, our 2 units keep the rig very cool and have no trouble keeping up with the heat, I just can't seem to keep them running with the stupid Dometic thermostats.

[sourdough]

By the way we have the stackable Splendide washer/dryer units. We have no problem doing laundry with both ACs going....on 50A service. I would not attempt it on 30A.

[RMcNeal]

Cool. Glad to hear it. I thought that made more sense.

[rayegelhoff1]

I have a 2016 305RL that has a 15K blizzard nxt, it would not keep running , the temp would vary 20 + degrees. I replaced the thermostat and moved it off of the wall from where factory put it. Now works great , had 99 degree day and it kept a constant 76 inside.

[skippydoo]

Our 2019 HC331RL had air flow problem which resulted in a very slow cool. We need a cold unit living in NC and traveling to the south often. So so air does not work for us. Not a fan of this quite cool fyi. *Thankfully our bedroom has a dump AC* this saved us a few times.

Husband had to put pvc pipe in living/dining room vents too. After he dug around with his arm UP in the vents to clear the area and re-tape the foil stuff.

Also he made cones out of white coil stock (ask lowes if not sure) to re-direct air flow DOWN since the air flow was only going across and over outlet. Nothing there to direct downward into cabin at all. Go figure.

The cone is screwed to pvc deflector. . We also purchased new vent thingies to replace the factory ones. These work a lot better. Found on amazon.

Valterra A10-3357VP Rotating/Dampered Heating and A/C Register - 4" ID x 7" OD, White

Since these fixes our Rig is freezing with tons of blowing air, and i do mean tons of air. Having our Rig in the middle of summer in Orlando---it had no problems keeping up with the demand.
*we never set our ac on automatic*---no proper southern would do such a thing

100 plus degrees outside, cabin cools easy 65'...true story.

[eZAK]

I spoke with the dealer yesterday. They said they checked both A/C units and found them to be operating with in specs. I will check the duct work when I get the rig back.

As far as the power goes, I did run both A/C units with the 50a > 30/20 wye.
In my HC the A/C units are wired on the same leg. Verified with a tester.
I marked that leg on the wye with some colored tape. Plugged that leg into a 30a outlet and the other leg 30>20 into a 20a GFCI.

No tripping and both A/C's running. and Yes, I'm a Electrician with 35 yrs. in the trade.

[Mikelff]

Originally Posted by eZAK

Thanks for all your replies!
To clear up any confusion; We do have two Coleman units. Having two A/C units is new to us so bear with me.
After setting the rig up in a new spot, What is the procedure for cooling it down as quick as possible?
Assuming I'll need both units cranked up and 50A at the pedestal, OR can I get away with a wye? (50 > 30 & 20)

Is the duct work connected between both units or only to the rear unit?

I'll also assume that the BTU's are the same for both and that they'll draw the same amperage, correct?

And before anyone says "go check your rig" The HC is back at the dealer for some minor problems.

If you have 50 amp service you should use that. Some rigs have AC units with different BTU ratings, like mine. For initial cool down keep as many slides in retracted position as you can, or partially open the ones you need to. This gives you less volume to try and cool down . Once the rig cools enough, open your slides. Also, when you pack up or first hook up, make sure your AC units are in the off position. This prevents unnecessary power surges. Also check and make sure breakers are off at the power stand before you flip the power on. Seems like a simple thing but I watched a guy blow out his electric system because he had not shut off his AC units inside the rig and probably had left other stuff on. He didn’t check to see if the breakers/ power at the stand was off and when he hooked up it all blew. He must have been new to RVing. Most air duct system these days connect both AC units to the same duct work.