Generator, EMS and Auto Start

[DirtyMax88]

Good Morning everyone. We have finally got around to having the generator installed in our LM. We decided to go with the on-board Cummins Onan 6.5Kw LP Gen. Correct me if I'm wrong, but the Generator DOES run through the power/electric management system on our rig, just like when we are hooked up to shore power? My biggest concern was over loading the Gen, if we have two a/cs running, residential fridge, sat, microwave etc or something else that draws decent watts/amps. I just wanted to double check that? My other question is about the "auto start" feature I have seen around the forum for the generator and if it's necessary. What exactly is it purpose, just to help with LP consumption? The techs will be installing the Gen in the next few days, so if I need to get them to add the auto start feature, I will.

Thanks in advance for the input!

-Will

 

[danemayer]

Hi Will,

The Power Control System (PCS) does have a capability that senses that power is coming from the generator and adjusts loads accordingly. I believe this comes from the generator's hour meter wiring. It's probably part of the generator prep.

If the generator prep didn't provide the connection to the Power Control System, it'll need to be added. See page 4 of the installation instructions at this link.

I would expect that the PCS programming assumes maximum wattage based on the Onan 5500. I'm pretty sure that you can't get custom programming in the event that it limits you to 5,500 watts rather than 6,500. I doubt there's a workaround other than disconnecting the wire from the hour meter. If you do that, you'll have to manage loads on your own while running the generator.

 

[LBR]

Our factory installed 5500 gas Onan in the CY runs thru the PCS and shows 45 amps, with 3 different sheds available and are the 3 ACs. I would ASSUME the 6500 genset should have a full 50 amps showing on the display....just a guess.

 

[DirtyMax88]

Hi Will,

The Power Control System (PCS) does have a capability that senses that power is coming from the generator and adjusts loads accordingly. I believe this comes from the generator's hour meter wiring. It's probably part of the generator prep.

If the generator prep didn't provide the connection to the Power Control System, it'll need to be added. See page 4 of the installation instructions at this link.

I would expect that the PCS programming assumes maximum wattage based on the Onan 5500. I'm pretty sure that you can't get custom programming in the event that it limits you to 5,500 watts rather than 6,500. I doubt there's a workaround other than disconnecting the wire from the hour meter. If you do that, you'll have to manage loads on your own while running the generator.

Thanks Dan. I will get in contact with them today to confirm some of these questions. The only reason we went with the 6500 was because of the wattage drop on the LP vs Gas. I was under the impression that the 5500 LP produces about 400-500 less watts. But if the PCS is assuming max watts based on the 5500, then getting the 6500 just seems like a waste of $$ and power. When the tech and I talked he seemed to think that 6500 was the way to go to have plenty of extra power, but we definitely didnt take into account what you mention about about the max watts programmed into the PCS.

 

[Jesstruckn/Jesstalkn]

I see no need to go up to a 6500. The 5500 works perfectly with RV and the PCS system. I can run everything I need to with it. I guess if you do alot of dry camping using all 3 AC's and need to use the microwave you might need a little more.
Make sure if you do switch to the 5500 get the one with the 2 30amp breakers not the one with 1 20amp and 1 30amp.
The auto start is a cool feature that I'd like to have. I think it was a $500 unit that has to be installed into the system.
I looked into it a while back but can't remember the details.
It will start the Gen if shore power is lost and the temperature drops or rises above your settings.
Good for pets left in the RV. Also will start if battery voltage drops below a set voltage.
I think it's a cool feature but it's not really something I need just something I want.

Jerrod


Sent from my XT1585 using Tapatalk

 

[DirtyMax88]

I see no need to go up to a 6500. The 5500 works perfectly with RV and the PCS system. I can run everything I need to with it. I guess if you do alot of dry camping using all 3 AC's and need to use the microwave you might need a little more.
Make sure if you do switch to the 5500 get the one with the 2 30amp breakers not the one with 1 20amp and 1 30amp.
The auto start is a cool feature that I'd like to have. I think it was a $500 unit that has to be installed into the system.
I looked into it a while back but can't remember the details.
It will start the Gen if shore power is lost and the temperature drops or rises above your settings.
Good for pets left in the RV. Also will start if battery voltage drops below a set voltage.
I think it's a cool feature but it's not really something I need just something I want.

Jerrod


Sent from my XT1585 using Tapatalk

Thanks, I appreciate your input Jerrod!

 

[esscobra]

X2 on what Jerrod said - all those features are nice- but not mandatory- the lp units are about 20% less output than gas units- that's why they still produce the 6500 lp model- and its better to have more power than not enough- I bought the 7k fuel injected unit- same size as the 5500- and fuel consumption is nearly identical