View Full Version : Onan Energy Command EC-30W Auto Gen Controller- Update

04-20-2010, 04:49 PM
I just purchased an Onan Energy Command EC-30W automatic generator controller from Onan. Does anyone with a Tour Master have this device? The instructions state that the inside remote charger should be plugged into a non inverter outlet. I've checked every outlet in the coach that I can find and all of them are on my inverter.

It is a great device in that it will monitor the batteries which I think is important because of the AC refrigerator and it will also monitor the inside temperature and start the generator to provide air conditioning if you have your units turned on. It will also keep track of your generator hours and inform you when it is due for service, etc.

My concern however, is what to do about not having a non-inverter outlet to plug the charger into. I contacted a couple Onan/Cummins facilities this evening and they didn't have anyone working that knew anythng about the unit. Any help will be appreciated.

Chuck v
04-20-2010, 05:41 PM

Once again we are up against the frustrating lack of wiring diagrams for the GS coach line-up! I think that every AC outlet served by the left power center (in the wall under the refrigerator in my 40-C) would be from the inverter leg. It is possible that the loads protected in the middle power center might not be sourced from the inverter, such as the air conditioners, the basement freezer, the washer and dryer, the ac element of the water heater, etc. There is an outlet listed in this group, which is the bedroom recepticle -- might be the one on the frame of the bed itself...

Did you test that one?

I glanced at the Onan Energy Command EC-30W manual on-line at
http://www.cumminsonan.com/www/pdf/rv/e ... ual-en.pdf (http://www.cumminsonan.com/www/pdf/rv/ec30Wmanual-en.pdf)
and it is an interesting accessory, be sure to let the forum know how it works out when you get it working, thanks!


04-20-2010, 07:36 PM
I checked the receptacle on the side or the bed along with one in the rear corner at our window seat/dresser and both are connected to the inverter. I never thought of the washer and dryer compartment, I'll check it out tomorrow. I would hate to run a wire from the freezer compartment, but I will if I have to.

Another person that has one just communicated with me and said the device can be disconneted from the charger when in operation. He indicated that it's rechargable battery will last for a long time. So, I may try it before I do any rewiring.

As a side note, I had my inverter batteries changed out yesterday and had Trojan 125's installed. I'm conducting an experiment right now to see how long I can operate the refrigerator on the inverter. It has been running for 7 hrs. and the batteries are still at 12.5. With the combination of the new batteries and the Onan device, I should be in good shape for dry camping.

I'll keep the Forum informed as things progress.


04-22-2010, 04:01 PM
I finally got my Onan EC-30W to operate as it should. I had installed four new Trojan 125's prior to installation of the EC-30W. I then set the controller to start the generator when the house voltage dipped to 12.1 or the interior house temperature hit 76 degrees calling for air conditioning. The house temperature reached it's setting and the generator started. I immediately shut it off. I ran the inverter for a total of 18 hours with the full size residential refrigerator and two TV's running before the generator kicked on when the inverter reached 12 volts.

If I reset it for a lower volt minimum such as 11.8 or so, it should run a few additional hours.

The Trojan 125's are great batteries and provided much more storage capacity than I ever dreamed with this amount of load running. Complimented with the Onan EC-30W, I'm no longer concerned about dry camping with a residential refrigerator.

04-24-2010, 07:43 AM
I am looking into getting some battery's now and have found a Trojan distributor. Are you running (4) Trojan 125's?

for those who don't plan on dry camping often, would two larger battery's be better than four smaller battery's?

Chuck v
04-24-2010, 10:08 AM
The 4 each 6V deep cycle golf cart batteries (the T105 size that came with the coach, or the larger capacity T125 version) are MORE amp hour capacity than a pair of 12V lead acid batteries that would still fit under the hinge rod on the front cover of the Tour Master coach.

These 6V cart batteries in this configuration (series/parallel as shown in the Trojan user's guide at http://www.trojanbattery.com/Tech-Suppo ... sh_003.pdf (http://www.trojanbattery.com/Tech-Support/documents/UsersGuide_0708_English_003.pdf) ) provide about 450 amp-hours of 12 volt power to run your inverter.

By contrast, the expensive and massive Group 31 12v starting battery for the diesel engine is only rated at 100 A-H each, so two of these would only be 200 A-H -- and therefore just under half of the storage capacity of the four T125 batteries... The group 31 PC2150S by Odyssey costs about $350 each, some brands like Deka, Optima and Interstate are less money, but are also less capacity -- The Optima is 75 A-H for instance. These starting batteries do have the ability to provide more short term current for the high demands of the diesel starting motor, around 900 to 1000 CCA, but are not the best type of battery to use for sourcing the inverter.

In short, you want to maximize the CCA for a starting battery, but the deep cycle use for inverters requires that you maximize the amp-hour capacity of the battery. It is like comparing a draft horse to a pony express mount -- different use environments entirely.:!:

Hope this helps...


04-24-2010, 01:51 PM
Yes, I just installed four Trojan 125's this week before I installed my EC-30W. I would have installed 145's, but they won't fit under the hood bar, because they are almost an inch taller.