2022 Cornerstone and the missing inverter

[Maddog11capt]

Hey folks;

We're in the market for a new Cornerstone. As I was researching the differences between the 2021 and 2022 Cornerstones, I discovered that the 2022 Cornerstone is missing an inverter. (Ok, well let's just say that Entegra decided not to install two of them starting in the 2022 model year)

I was looking at the sheet that Larry (LWBAZ) was kind enough to attach in a previous post and it says "Eliminated second inverter but changed breaker from 30 amp to 50 amp on the single 3,000-watt pure sine inverter."

Huh??? What does changing the circuit breaker from 30 amp to 50 amp have to do with removing one of the inverters? Unless my basic understanding of electricity is wrong, isn't a 3000-watt inverter still a 3000-watt inverter regardless of the circuit breaker size? What am I missing?

Thanks for helping me understand what has changed.

ron

A.K.A. Maddog11capt

[hpykmpr47]

Originally Posted by Maddog11capt

Hey folks;

We're in the market for a new Cornerstone. As I was researching the differences between the 2021 and 2022 Cornerstones, I discovered that the 2022 Cornerstone is missing an inverter. (Ok, well let's just say that Entegra decided not to install two of them starting in the 2022 model year)

I was looking at the sheet that Larry (LWBAZ) was kind enough to attach in a previous post and it says "Eliminated second inverter but changed breaker from 30 amp to 50 amp on the single 3,000-watt pure sine inverter."

Huh??? What does changing the circuit breaker from 30 amp to 50 amp have to do with removing one of the inverters? Unless my basic understanding of electricity is wrong, isn't a 3000-watt inverter still a 3000-watt inverter regardless of the circuit breaker size? What am I missing?

Thanks for helping me understand what has changed.

ron

A.K.A. Maddog11capt

Not sure but I think they are under the assumption that adding a heavier breaker will not allow the breaker to trip as easy. Apparently the Inverter is capable of handling the load but the breaker was not.

[brobox]

The major drawback to the single inverter/charger is going to be the single charger taking twice as long for the batteries to charge. In most cases, nobody will know it is taking twice as long for the batteries to charge after they are plugged in.
Just looked at the brochure on my 21, it is listed as 3,00o watt with two inverters. I thought is was 4,000w. Show how much I don't know about the newer models.

[rorr1821]

Originally Posted by Maddog11capt

Hey folks;

We're in the market for a new Cornerstone. As I was researching the differences between the 2021 and 2022 Cornerstones, I discovered that the 2022 Cornerstone is missing an inverter. (Ok, well let's just say that Entegra decided not to install two of them starting in the 2022 model year)

I was looking at the sheet that Larry (LWBAZ) was kind enough to attach in a previous post and it says "Eliminated second inverter but changed breaker from 30 amp to 50 amp on the single 3,000-watt pure sine inverter."

Huh??? What does changing the circuit breaker from 30 amp to 50 amp have to do with removing one of the inverters? Unless my basic understanding of electricity is wrong, isn't a 3000-watt inverter still a 3000-watt inverter regardless of the circuit breaker size? What am I missing?

Thanks for helping me understand what has changed.

ron

A.K.A. Maddog11capt

This is what I believe happened:
In 2018 or 2019 Entegra went with the new “Hybrid Inverter with 3000 watt and 60A reset breaker”. Previous model had 30A reset breaker and 2800 watt. What Entegra did not do at that time was upgrade the wire from 10 gauge to 6 gauge wire for the the new 2ea 3000 watt inverters. So the new inverters still had 2ea 30A breakers in the electrical box above the driver seat. They could not put 50A or 60A breaker for the 2 inverters in the box for the simple reason they had not upgraded the wire. What I believe has happened in 2022 in effort to reduce cost they realized we can upgrade the wiring eliminate an inverter and maximize the features of the 3000 watt inverter capability at the same. Now that being said there is a draw back because you do loose some battery charging capability. Personally, I never understood why Entegra did not make the change when the new 3000 watt inverter with the 60A breaker came out. May be they just wanted to see how the new inverter performed.

I have not seen a 2022 so I am making big assumption they have upgraded the wire from the inverter to the breaker box above driver seat and changed the breaker from 30A to 50A or 60A.

Just my option.

Ray

[Gary.Jones]

Ron

I see little logic in this change. As Chuck said, changing the wiring and the circuit breaker is just a dumb way of dealing with this and the main effect is that now there will be much longer times to recharge the house batteries. This change reduces redundancy, increases charging times, reduces cost (but at a cost to owners) making failures of the one remaining Magnum now mission critical. Someone at Thor musta wondered why they had two, thought profits could be increased and asked why the old arrangement. The old answer was not good enough and therefore, the change.

Gary

[rorr1821]

There seems to a fixation on battery charging when it comes to this inverter issue. You can only power so much from a battery bank before you reach 50% discharge. Granted I have Aspire with a 2800 inverter but I do have 4ea L16 batteries. When we travel most of the time we dry camp between destinations and unless it is hot I do not run the generator all night. The wife watches the TV, sleep apnea machine runs through the night, refrigerator operates, etc. The next morning my Magnum screen tells me the batteries are not below 50% and generally at 60% -75% charge. I run generator for few hours and the batteries get up to 95% or so. While I am driving there seems to be some charge going to the battery bank also. When we stop I run generator so more charge going to the batteries and when we stop for the night the batteries are fully charged.

I did install Magnum Energy battery monitor with a shunt which measures the use of batteries and provides a very accurate percentage of battery charge remaining. I do not rely on voltage as a measurement of discharge.

Ray

[MRUSA14]

Entegra was the only one in the market segment with two inverters. I used to wonder why two, when the competition all had only one. I guess somebody at Entegra wondered that too. Aside from speed of battery charging, there is no difference in functionality that I can tell.

[Turbojack]

I do not have an Entregra but with my two inverter/battery charges there are times when I see it putting in over 100 amps into the batteries, I believe each inverter can only charge to a max of 100 amps.

Enterra was not the only one with two.

Agree with Gary on redundancy of two.

A 3000W inverter can only put out 25 amps of 120V power on batteries. If you have two and do not need the extra 120V amps on batteries the second inverter is draining the batteries by natural loses and not being used.

Here is my take on the 50 amp circuit. This circuit is going to a breaker panel where the circuits are sent to different items. When on shore power or generator the transfer switch in the inverter is going to allow 50 amps get through to the panel for item use. When you are on inverter you will have more items that are on the inverter to use. Problem is you can only use up to 25 amps before the inverter will shut down.

[757driver]

Originally Posted by Maddog11capt

Hey folks;

We're in the market for a new Cornerstone. As I was researching the differences between the 2021 and 2022 Cornerstones, I discovered that the 2022 Cornerstone is missing an inverter. (Ok, well let's just say that Entegra decided not to install two of them starting in the 2022 model year)

I was looking at the sheet that Larry (LWBAZ) was kind enough to attach in a previous post and it says "Eliminated second inverter but changed breaker from 30 amp to 50 amp on the single 3,000-watt pure sine inverter."

Huh??? What does changing the circuit breaker from 30 amp to 50 amp have to do with removing one of the inverters? Unless my basic understanding of electricity is wrong, isn't a 3000-watt inverter still a 3000-watt inverter regardless of the circuit breaker size? What am I missing?

Thanks for helping me understand what has changed.

ron

A.K.A. Maddog11capt

Ron,

You are right a 3000W inverter is 25amps AC or about 250 amps DC. The breakers in question have nothing to do with the inverters output but are related to their pass through capability.

When there were 2 inverters each with a 30A breaker an owner could easily overload 1 inverters pass through ability while plugged into 50A shore power by running the microwave, TV, fridge, and a space heater all at once. With a 50A or 60A breaker on the side of the inverter and in the breaker panel this occurrence will be much less prevalent.

From an operating in use standpoint an owner will not notice any real difference with only having 1 inverter vs 2. With what the other manufacturers are doing I am surprised the 2 inverter installation lasted as long as it did.

Where a difference will be noticed is with dry camping. The generator will have to run approximately twice as long on a 2022 coach vs a 2021 coach to get the same number of amps back into the battery bank.

[Dieselgem]

Just my opinion, but I prefer having the second inverter.

[Cruzer]

I too would prefer two inverters, for the redundancy and for the faster battery charging. However, most coaches do only have one inverter and seem to be getting along fine.

The older Magnum 2800 watt inverters did have 30 amp transfer switches so half of the inverter fed loads were on one inverter and the other half on the other. The newer MSH3012 is a hybrid inverter with a 60 amp transfer switch so it can handle all of the pass-through power on one circuit. That is a benefit because there are times when one inverter isn't doing much while the other one is loaded up. You no longer have to slit the loads with the MSH3012. Also, all inverters do have a temporary surge capacity so they can snap more than their rated output for a few seconds to handle a brief surge, such as a motor starting load from a fridge or whatever.

Lastly, the MSH3012 is a hybrid inverter. The other inverter transfer switches are in an "either/or" state. You either get inverter supplied power or pass-through power from generator or shore power. The hybrid MSH3012 can combine pass-through power with inverter supplied power if necessary. This would typically be used when on a 30 amp shore power during a surge in load, such as starting an air conditioner, turning on a microwave, etc. The MSH3012 will add some inverter boost to increase the available power beyond the 30 amp shore power so that things stay running rather than get shed by the EMS. That won't hold forever though so at some point the load needs to come back down to protect the batteries. Personally, I rarely encounter 30 amp shore power pedestals any more so it's not a big thing for me.

The MSH3012 does offer some benefits but going to the single versus double does bring your battery charge time back down to what everyone else pretty much has and you don't have any redundancy, but then that's pretty much the way the industry is.

FWIW I did install a prototype MSH3012 inverter in out Allegro Bus, replacing the MS2812. It was a bit of a project because of the need to run large wire gauge for the AC wiring and reconfigure the sub-panel to accept the single pole 120 feed to the inverter's 60 amp transfer switch from the previous 120/240 two pole (30 amps per pole) configuration. In order to control the inverter assist feature I also had to work with Precision Circuits to upgrade the EMS system to manage the inverter assist. Without that kind of programming the inverter assist won't ever kick in, although I'm sure that Firefly has the Vegatouch programmed to perform that function.

[brobox]

Excellent explanation, thank you for breaking that down Mark.