air conditioner soft starter for Honda eu2000i generator

 

Here is some preview of my recent battle to sort out some pesky issues with the Coleman low profile AC which I had planned to use my Honda EU2000i generator to power it, in Eco mode which is a very tall order. I want to use Eco mode as the generator will only run as fast as the load requires, hence gives the longest running time and most fuel efficient. However even not running in Eco mode, the surge current when the AC restarts it would often trip the overload protection of the generator. You cannot reset the electronic breaker without powering done the generator and then restarting it.

I surveyed all the available RV AC soft starter, from low end to the most expensive. I was dissatisfied as well as distrust their claims. I want to solve this once and for all, so I decided to use industrial AC motor soft starter from Schneider Electric. These industrial modules are not designed to be a drop in for RV ACs. I figure I can make it work, and hopefully avoid having have to tear the AC or ducting in order to modify the wiring. Today I wired up my bench test set up so I can tool prove the design before committing to install it. Here is one teaser photo.

I racked my brain out before coming up with the wiring design that can interface to the existing circuit; it was not trivial nor obvious

I had the hardest time understanding how to wire up this Schneider Electric AC motor soft starter; there is no description beyond this one page diagrams and these industrial schematics are the most cryptic and assume some insider trade knowledge

I had been performing torture tests on this with a staled tank of fuel in the generator running in Eco mode

this is a perfect location for the soft starter as I can service it from the bath's access door

reclaimed the storage

The difference in the temperature regulation when the capillary tube is in the active air stream makes all the difference. The AC now cycles much more frequently to tightly maintain the target temperature. I dislike the high noise of the blower fan running at high speed. I have yet to procure a high low switch that can fit into the location of the Westfalia fan speed control as most switch would interfere with the two contact terminals of the thermostat. I need to do more testing to see if I really need to use the high setting of the blower.

So far I am very happy with the result of the design and installation.