Three 15k BTU Air Conditioners

MuddFlap · 03-22-2017, 07:20 PM

Who else has 3 units?
Can you run all 3 units on 50 amp shore power?
The math doesn't add up to be able to do it, but the salesman says... Well we know where that story goes.

atom ant · 03-22-2017, 07:57 PM

Should not be a problem at all. Remember 50A service is actually 2 legs of 50A or 100A.

Your power management system should prioritize and shed loads of other equipment to prevent overload - such as the HW tank electric, Dryer, etc before AC, then it will start shedding AC.

We run 3 13500 ACs on 50A service all the time.

MuddFlap · 03-22-2017, 08:44 PM

O. M. G. You mean to tell me the salesman had it right!?!? Thanks Atom, you're atomic!

Ford truck guy · 03-22-2017, 09:14 PM

Quote:

Originally Posted by MuddFlap

O. M. G. You mean to tell me the salesman had it right!?!? Thanks Atom, you're atomic!

Not sure he has ever been called that before !

Char & Steve · 03-22-2017, 09:43 PM

Quote:

Originally Posted by MuddFlap

Who else has 3 units?
Can you run all 3 units on 50 amp shore power?
The math doesn't add up to be able to do it, but the salesman says... Well we know where that story goes.

OK Mudd.... Just rub it in!!!!!!

All of us out here or lets say 99.8% have only two so when you pull in to the Rally some year we are all going inside yours to cool off.

Steve

Jim & Mary · 03-22-2017, 10:55 PM

That's right after they wipe the drool off their mugs after they take a tour of your custom coachwork...........

Randalf · 03-22-2017, 11:23 PM

So we just got (what we hope) was a great year-end deal on a new
2016 Redwood 38RD with two units. Are we going to regret not waiting to get a year-end deal on a 2017 model with three units? We traded in our '16 Coachmen Chaparral 338 with two units (15000 & 12500 BTUs) to buy the RW, and we know from experience that the two a/c's on that trailer didn't cut it in Las Vegas in August. If it was 102 outside, it was 82 inside. Will the insulated windows and thicker walls of the Redwood keep us cooler than the Chaparral could in the same conditions?

atom ant · 03-23-2017, 01:49 AM

Quote:

Originally Posted by MuddFlap

O. M. G. You mean to tell me the salesman had it right!?!? Thanks Atom, you're atomic!

hahaha - the salesman probably didn't know at all, but he had a 50-50 chance

BugSplatter07 · 03-23-2017, 03:13 AM

We have 3 AC units and never had any issues with all 3 running at the same time. I will say that we have only ran all 3 at the same time about 4 times. That was just to cool it down fast as we were returning back to the camper after being away from it for a long period of time.

Salesman is just like a blind squirrel, they find a nut every now and then.

HTX · 03-23-2017, 03:54 AM

Quote:

Originally Posted by Randalf

So we just got (what we hope) was a great year-end deal on a new
2016 Redwood 38RD with two units. Are we going to regret not waiting to get a year-end deal on a 2017 model with three units? We traded in our '16 Coachmen Chaparral 338 with two units (15000 & 12500 BTUs) to buy the RW, and we know from experience that the two a/c's on that trailer didn't cut it in Las Vegas in August. If it was 102 outside, it was 82 inside. Will the insulated windows and thicker walls of the Redwood keep us cooler than the Chaparral could in the same conditions?

I think you will see a difference. I had a 2003 KZ New Vision with the factory insulation upgrade and it did not compare to the RW. I'm in South Texas at 100 + when I got home from work my the 6 ft. shorter KZ with 1 15k unit would be at 84 or higher. In the same location the RW with one unit running the temp would be around 76 degrees in August/September last year.

As a comparison my old 5th had most of the windows facing south (I used bubble foil insulation on those windows.) The RW has the dining area facing north which is a huge plus. It also has awnings on all of the windows I did not use those due to high winds but a pull down solar screen on the rear window was useful during the peak hot season.

Overall I have been pleased with the insulation compared to my old unit.

HTX

HTX · 03-23-2017, 03:59 AM

Quote:

Originally Posted by Randalf

So we just got (what we hope) was a great year-end deal on a new
2016 Redwood 38RD with two units. Are we going to regret not waiting to get a year-end deal on a 2017 model with three units? We traded in our '16 Coachmen Chaparral 338 with two units (15000 & 12500 BTUs) to buy the RW, and we know from experience that the two a/c's on that trailer didn't cut it in Las Vegas in August. If it was 102 outside, it was 82 inside. Will the insulated windows and thicker walls of the Redwood keep us cooler than the Chaparral could in the same conditions?

I think you will see a difference. I had a 2003 KZ New Vision with the factory insulation upgrade and it did not compare to the RW. I'm in South Texas, at 100 + when I got home from work my 6 ft. shorter KZ with 1 15k unit would be at 84 or higher. In the same location the RW with one unit running the temp would be around 76 degrees in August/September last year.

As a comparison my old 5th had most of the windows facing south (I used bubble foil insulation on those windows.) The RW has the dining area facing north which is a huge plus. It also has awnings on all of the windows that I did not use those due to high winds but a pull down solar screen on the rear window was useful during the peak hot season.

Overall I have been pleased with the insulation compared to my old unit.

HTX

brad chilton · 08-06-2018, 09:56 PM

Anyone with a 2018 have 3 a/c ‘s they can run at the same time ? I can only run 2 of the three at any given time .. Redwood has 2 - front and mid units - on same breaker running thru ems system , 3 rd unit in bedroom on diff leg of breaker box and is always avail .. So I can run the bedroom and only one of the front or mid units ... both front and mid units are labeled and have 20 amp breakers in breaker box , both units are wired together .. Keystone CS told me that’s how it’s done period ...
Shouldn’t I have both units on individual breakers ??
Any help would be appreciated .. Also how difficult is this job to do ??
Brad

xtasee · 08-06-2018, 10:33 PM

Brad,

I am not the expert but the way you explain your wiring is exactly the way I understood they were designed. You can only run one ac off of each leg coming out of the pedestal.

I also have been told that the two on the same leg are switched back and forth based on demand. Once the rear unit reaches the setting on the thermostat, then the mid unit would take over until it reaches it's setting and visa/versa. Does yours switch automatically? If not, there could be a problem with your power management system.

atom ant · 08-07-2018, 01:15 AM

Well something went astray - some say they can run 3 at the same time, but if the EMS is sharing a circuit with 2 ACs you could never run 3. There is no point to having a 3rd if you can only run two - the whole point is to increase the Btuhs for the larger coach and taller headroom.

If Redwood did indeed wire it the way said (2 on one breaker controlled by EMS), I would modify it to get all tree running at once.

I would pull one of the ACs off the EMS and put it on it's own breaker, and put the HW heater or Dryer on the other side of the EMS so it can share with the 3rd AC.

PS - I have 3 13,500k ACs running all the time in our MH and I hook up to the same 50A service everyone else does. I have EMS, but it sheds loads to how I prioritize, starting with HW and dryer.

brad chilton · 08-07-2018, 03:07 AM

BRAD
Thanks for your reply as this is what I posed to keyston cs...i was told this is the way its wired.. front 2 on same breaker, even thought they have a second breaker marked along with the Ems... bedroom is other circuit with its own breaker ...cs told me I could only run a//c in the front .... some thing is totally screwed up inaddition with the ems, I had to run wire to gen hourmeter as it it didn’t recognize the gen , and when its on 30 amp step up , I can only 1 run 1 ac at a time as ems sheds the second ...My understanding was the ems was setup so you could run 2 acs....Dealers I have talked to say just bring it in ... in a month or so.. i need to d=fix this now as summer temps on westcoast are getting brutally hot ...
So let me ask you, how difficult is it to move 1 ac to the breaker its already set up for ? Can I do it myself or do I need an rv mobile guy or an electrician?

Thanks for your input..
Brad

BugSplatter07 · 08-07-2018, 04:45 AM

I can run all 3 of the a/c units at one time with no problem. When all 3 units are running it doesn’t take long to cool things down. It will go from low 80’s to upper 60’s in about 15 minutes or less.

atom ant · 08-07-2018, 03:48 PM

Sounds like somewhere between 2016 and 2018 they changed the design. I'm hoping it wasn't to accommodate a change to the duct zoning. I'm assuming the 2018 supply and return ducts can still handle the 3 acs running like in 2016.

Brad -
I'm don't have a visual of how the ACs are connected to the EMS, so I'm not sure how you would need to remove it, but to get it on the breaker all you need is the hot (black) removed from EMS and attached to the breaker (the breakers pop out to work on them). The neutral should already be on the neutral bar, as well as ground on the ground bar. Again, I don't know how their EMS is tied in, as they came out after we bought ours. I would do it myself but I was a journeyman for several years. I don't know what your skill set is. Any electrician could. I don't think a mobile RV tech would touch it as it is a modification.

katy4man · 08-07-2018, 04:55 PM

We have a 2018 3821rl and that's the way ours works as well seems like the 2 in main living area alternate automatically between themselves and of course the bed room is a heatpump on its on breaker also....also was told by the tech at Tulsa rv that was the way they work...just my 2.5 cents worth....and as far as ducting goes bedroom is definitely separate from living area...

brad chilton · 08-07-2018, 08:32 PM

Quote:

Originally Posted by katy4man

We have a 2018 3821rl and that's the way ours works as well seems like the 2 in main living area alternate automatically between themselves and of course the bed room is a heatpump on its on breaker also....also was told by the tech at Tulsa rv that was the way they work...just my 2.5 cents worth....and as far as ducting goes bedroom is definitely separate from living area...

Are you saying you cant run your 3 ac’s at the same time ?

katy4man · 08-08-2018, 02:39 AM

Im not 100% sure how it works we just got it but about 3 weeks ago it was 100+ degrees for about 5 days and 90 at night set all tsats on 70 and it only got up to 76 inside in the heat of the day sounded like the 2 in living area cycled between themselves but they may all 3 been running when I get some time to check em out will report back as for now seems to be working as by design...have been fighting leaking shower and broken bottom door roller which redwood sent part to me and I caulked shower at bottom door track so far so good....

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