Hello. With summer just around the corner I've been considering the addition of the 3rd AC unit on my 2018GK. I have some question for those of you that have the 3rd AC unit or who have installed one. My AC section of my power distribution panel is full so I cannot add the breaker there. For those who have the 3rd AC unit from the factory where is the breaker installed? If you added the 3rd unit at the dealer how/where did they install the breaker? I'm pretty sure I need to upgrade my Power Control System module and control panel as well to accommodate the 3rd AC unit. My current PCS only controls two AC units and the electric water heater. For those of you that have the 3rd AC and the PCS could you post a pic of your PCS panel? Thank you!

First let me say I don't have 3 acs & am not an electrician.
As I understand though even with 3 acs you'll only have 2 running at a time unless the 3rd is powered separately with its own power source.
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First let me say I don't have 3 acs & am not an electrician.
As I understand though even with 3 acs you'll only have 2 running at a time unless the 3rd is powered separately with its own power source.
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It’s my understanding that the Power Control System does allow the operation of 3 AC units on a 50 amp service. It does so by monitoring the loads and allowing loads to come on and by shedding load as needed. In my coach the front AC is more than enough to cool the bedroom/bath deck but the other AC struggles to cool the main part of the coach. I believe the PCS system will allow use of all 3 units and will manage power distribution to all three accordingly. For example it may allow power to both rear units and once start up loads have peaked it will allow load to the third unit. It may also shed load as needed. The PCS in my coach allows me to run both my ACs when on generator power with my Onan 5500. Hopefully someone with 3 roof AC units and PCS will chime in.

We were in Disney here in Florida this past October when they had a week of 95 plus temps and we kept our interior at 72 to 74 keeping the shades down and both ACs running.

It is not easy or cheap to upgrade you current electrical system to handle 3 A/C units.
Our Redwood is a 2014 38FL with 2 A/C units and no power management system.
I invested my time and resources in improving our current A/C units performance and our Redwoods insulation.
Our A/C units performance was improved by adding output Registers to meet / exceed the A/C manufacturers minimum requirements (our Redwood did not have the A/C manufactures minimum recommended output registers of 5 per 15K A/C unit), adding A/C returns and removing return air flow blockage so the A/C units work more efficiently.
The insulation was improved by correcting / installing insulation in our Front Cap area, installing Slide Toppers to keep direct Sun Light off the top of our thin Slide Roofs.
When our Roof system failed during warranty, we had the RV Armor System installed and they installed white coating on the top of our roof with tan coating on the side wraps to match out coach's color. The white roof top also helps with direct sun heat also.
Now I am able to maintain comfortable temperatures even on the hottest days with direct sun.

I have 2019 390MB with 3 AC'S. With the EMS system you can run all 3 AC'S at the same time. The EMS will shut one off when power is needed. Here is picture of breaker's.

Rob,

What was the dimension of the foam blocks that you used to wedge up the AC duct work??

Joe

I have 2019 390MB with 3 AC'S. With the EMS system you can run all 3 AC'S at the same time. The EMS will shut one off when power is needed. Here is picture of breaker's.

Dlord017 thank you for the post and the photos! Interestingly I figured your PCS module would be different with 3 AC units. It looks exactly like my PCS module with WH, AC1 and AC2. I would have thought you would have all three of your AC units on the display. Perhaps I won't have to upgrade the PCS if I add the third unit!

We have a 2017 39MB with 3 A/C units, the PCS module looks exactly like Dlord017's, so far not a single problem with the setup and all 3 units seem to cycle on and off as needed when the temperature dictates. I also thought the 3rd A/C unit would be represented on the PCS module, but that's not the case.

I definitely think a wiring diagram for the PCS and three AC units is in order for me to understand exactly how they are wired and work. I wonder if Redwood can provide this? Thank you all for responding.

I definitely think a wiring diagram for the PCS and three AC units is in order for me to understand exactly how they are wired and work. I wonder if Redwood can provide this? Thank you all for responding.

NOPE!
That's company secrets!
Not sure it would be of much help if you were lucky enough to get a set. They were/are not "as built", but mere suggestions to the folks on the line, not sure there are any 2 RWs wired/plumbed/satellite cables wired the same, it all depends on which guy/gal was running it & their mood at that moment & time of day.

I definitely think a wiring diagram for the PCS and three AC units is in order for me to understand exactly how they are wired and work. I wonder if Redwood can provide this? Thank you all for responding.

NOPE!
That's company secrets!

Not sure it would be of much help if you were lucky enough to get a set. They were/are not "as built", but mere suggestions to the folks on the line, not sure there are any 2 RWs wired/plumbed/satellite cables wired the same, it all depends on which guy/gal was running it & their mood at that moment & time of day.

Perhaps Precision Circuits could help. On their website they do provide wiring diagrams for a number of different manufacturers but nothing for Redwood.

http://precisioncircuitsinc.com/category/120v-energy-management/

Attached is Heartland Wiring Diagram. I'm guessing using the various wiring diagrams I could figure out the wiring for load shedding three AC's and the water heater. Based on everyone's responses I probably don't need to upgrade my PCS hardware.

Wow Joe, it has been years ago I did the blocks to hold up the falling down bubble foil, I do not remember how thick it was.

Rob,

What was the dimension of the foam blocks that you used to wedge up the AC duct work??

Joe

Wow Joe, it has been years ago I did the blocks to hold up the falling down bubble foil, I do not remember how thick it was.
I went to Lowes and bought some foam block after measuring the height between the duct and the ceiling where the bubble foil is.

Thanks Rob,

I was cleaning ducts and saw this... I am not ready to cut holes and add return vents so I was gonna try to get something long enough to add in there from the existing vent..