AC’s will not keep Solitude 373 FB cool

[huntr70]

Don't exactly know how they work, I'm not a tech.

Try it on a Solitude and let us know how it works.

Does your Momentum have the EMS on it?

[Aridon]

Don't exactly know how they work, I'm not a tech.

Try it on a Solitude and let us know how it works.

Does your Momentum have the EMS on it?

Yes, its primary purpose is to shed loads when on 30 amp service. Turn on hair dryer while the air is on, the EMS turns off the air and lets the hair dryer run. Once the hair dryer load is off for a minute or two, the air is allowed to fire back up. Keeps you from having to go out and flip the pedestal breaker a few times a day because 30 amp is very limiting.

On 50 amp, the EMS is essentially bypassed. Some of them will look for an open neutral type situation and not allow the voltage to enter the plugs (our Newmar's EMS did that and saved all our electrical items) but most of them are basically in pass through mode when on 50 amp load wise. They essentially do nothing for load balancing and are not necessary.

When on 50 amp, you have two legs @ 50 amps each which are 180 degrees out of phase and use a shared neutral. So the loads from phase 1 and 2 essentially subtract each other out on the neutral. The limiting factor in most cases (assuming proper balancing) is the weakest breaker in the chain. Either the pedestal will go if you draw more than the leg can handle or one in the panel inside depending on what you are doing. We've blown the pedestal breaker a few times when we first picked up our momentum because the washer dryer was on the same phase as two of the air conditioners. 2 airs plus the dryer is a lot of amps so I changed that really fast after a few trips to reset the breaker outside. The EMS didn't kick in because the EMS is basically off when in 50 amps when in comes to load balancing.

Now I'm not claiming to know it all, which is why I asked for your reasoning when you made the claim. This what my experience and limited knowledge has lead me to know in my many years fulltime with a variety of different RV's. I could very well be incorrect and if I am, I'm sure someone will be by to fix my mistake.

[huntr70]

Yes, its primary purpose is to shed loads when on 30 amp service. Turn on hair dryer while the air is on, the EMS turns off the air and lets the hair dryer run. Once the hair dryer load is off for a minute or two, the air is allowed to fire back up. Keeps you from having to go out and flip the pedestal breaker a few times a day because 30 amp is very limiting.

On 50 amp, the EMS is essentially bypassed. Some of them will look for an open neutral type situation and not allow the voltage to enter the plugs (our Newmar's EMS did that and saved all our electrical items) but most of them are basically in pass through mode when on 50 amp load wise. They essentially do nothing for load balancing and are not necessary.

When on 50 amp, you have two legs of 50 amp service and they are 180 degrees out of phase and use a shared neutral. So the loads from phase 1 and 2 essentially subtract each other out on the neutral. The limiting factor in most cases (assuming proper balancing) is the weakest breaker in the chain. Either the pedestal will go if you draw more than the leg can handle or one in the panel inside depending on what you are doing. We've blown the pedestal breaker a few times when we first picked up our momentum because the washer dryer was on the same phase as two of the air conditioners. 2 airs plus the dryer is a lot of amps so I changed that really fast after a few trips to reset the breaker outside. The EMS didn't kick in because the EMS is basically off when in 50 amps when in comes to load balancing.

Now I'm not claiming to know it all, which is why I asked for your reasoning when you made the claim. This what my experience and limited knowledge has lead me to know in my many years fulltime with a variety of different RV's. I could very well be incorrect and if I am, I'm sure someone will be by to fix my mistake.

I understand your theory, but when you didn't do the 3rd a/c option on Momentum, you didn't get the EMS either. It was a mandatory option when you put in 3 a/c units. Not on every one. That has actually changed for 2020 models, with a different system.

This is off the 2019 GD Momentum specs....."3rd 15k BTU A/C (Includes Energy Mgmt. System & 3-Zone Thermostat)"

In your theory, every 50 amp coach made with 2 a/c units should have an EMS "in case" you only have 30 amps available.

[cookinwitdiesel]

The EMS also comes into play when you are running 3 A/Cs on the 5500W generator that many of the Momentums have as well. That is more than a 30A service (3600W) but less than a 50A service (12000W).

[TheLexx]

Check out my thread on fixing the air conditioner divider between the cold air and return side of the AC unit. Also be sure you pop off the vent covers and feel the foil tape around the vent. For many folks that foil tape is not pressed down, thereby obstructing the cool air flow from the vents.

We we were just in Las Vegas in 105 degree temps and our 2 air cons had no issue getting the inside down into the low 70’s after the “repairs” I made. Previously we were sweating in that kind of weather as our units would not cool the coach down to below 80.

Another thing you dan do is to add some good window film to all the windows. I went to windowfilm.com and bought some 20% ceramic automotive film and applied it to all our windows. It only cost $130 to buy enough film for the whole trailer. This film is rated to reject 64% of the total solar energy. Your AC units won’t have to work as hard.

https://www.mygrandrv.com/forum/show...day-and-oh-boy

[Txfivver]

Interesting. I spent 4 days Fathers Day weekend in mine in San Antonio and no issues keeping it cool. It was sunny and in mid 90's and my two Coleman's kept it at 72 inside easily. When setting up I put them on hi cool auto and opened the dump valves on both units. Within 2 hours or so it cooled down and I went to low cool auto and used the ceiling vents, stayed comfy all weekend.

[KirbyRVA]

Check out my thread on fixing the air conditioner divider between the cold air and return side of the AC unit. Also be sure you pop off the vent covers and feel the foil tape around the vent. For many folks that foil tape is not pressed down, thereby obstructing the cool air flow from the vents.

We we were just in Las Vegas in 105 degree temps and our 2 air cons had no issue getting the inside down into the low 70’s after the “repairs” I made. Previously we were sweating in that kind of weather as our units would not cool the coach down to below 80.

Another thing you dan do is to add some good window film to all the windows. I went to windowfilm.com and bought some 20% ceramic automotive film and applied it to all our windows. It only cost $130 to buy enough film for the whole trailer. This film is rated to reject 64% of the total solar energy. Your AC units won’t have to work as hard.

https://www.mygrandrv.com/forum/show...day-and-oh-boy

Based on your thread, I will be checking my AC units and duct work as soon as we get back to the rig this weekend.

Tell me more about the ceramic film. How difficult is application?

[TheLexx]

Window film is not that hard to apply to our smallish windows. The website I linked to sells an installation kit. Just get the most basic one. The key is using the squeegees to get the air and water under the film out. Another tricky thing is many of our windows have curved edges and frames. It’s tricky to trim it exactly around the curved edge. Fortunately if you make a mistake on the upper edge the window valence will hide it. Just google window film in station. There are a lot of videos out there showing how to install the stuff. This is a totally worthwhile job to DIY.

Based on your thread, I will be checking my AC units and duct work as soon as we get back to the rig this weekend.

Tell me more about the ceramic film. How difficult is application?

[KirbyRVA]

Window film is not that hard to apply to our smallish windows. The website I linked to sells an installation kit. Just get the most basic one. The key is using the squeegees to get the air and water under the film out. Another tricky thing is many of our windows have curved edges and frames. It’s tricky to trim it exactly around the curved edge. Fortunately if you make a mistake on the upper edge the window valence will hide it. Just google window film in station. There are a lot of videos out there showing how to install the stuff. This is a totally worthwhile job to DIY.

Some of our windows (those on the patio side) are pretty big. At least we have two awnings that can be used to shade those......when it is not too windy.

[TheLexx]

Some of our windows (those on the patio side) are pretty big. At least we have two awnings that can be used to shade those......when it is not too windy.

You will have to check on the website whether they make a film that fits the length or width of your window. Fortunately in my case the largest window is the one by the dinette and the available film easily fit it.