Rbertalotto wrote:
. . . Once it tries to start again, the PI-EMS unit trips and the compressor never comes back on until I go outside and shut off eco boost.
If I deactivate the EMS, then the AC will function with both generators on eco boost . . .
If the a/c unit has NEVER operated with the PI EMS activated (using a generator), chances are you need to use a ground/neutral bonding plug. However, it sounds like your a/c unit has operated successfully with the PI EMS under certain conditions.
FWIW, the PI EMS is designed to disconnect power when voltage drops below ~104 volts. However, it will allow voltage to drop down to 90-104 volts during compressor start (if less than ~500 ms in duration) without returning an error (or shutting down power). The PI EMS does need at least ~90 volts to simply operate. Less than ~85 volts and the PI EMS quits operating and the relay defaults to the open (no output) position. When voltage drops to 85-90 volts, typically the PI EMS relay starts to chatter loudly.
I believe the Dometic 475915 (a popular OEM unit) has an LRA of 63 amps. My experience has shown two Honda EU2000i's will not reliably start this particular a/c unit with the Eco mode on. Sometimes hard-start kits help, sometimes they do little.
Results powering 13.5k BTU a/c units with one or two EU2000i's vary widely. There are some folks who can start their 13.5k BTU a/c unit with
one EU2000i. There are some folks who can't start their 13.5k BTU a/c with two EU2000i's paralleled with the Eco mode on. Why? Not all 13.5k BTU a/c units are created equal. In-rush current (LRA) can vary widely from one model to another. The a/c unit's inrush current needs (based on LRA) and the power source's (commercial or generator) ability to deliver sufficient inrush current to meet those needs determines whether a given a/c unit will start or not.
In many cases, a clamp-on inrush current ammeter can quickly isolate the source of the problem. Yes, voltage measurements are useful, but there are very few VM that can accurately read the those few ms of voltage sag during compressor start-up. That's why a good inrush current reading is so helpful.
Assuming you have no problems with a commercial power source, it's best to establish a good baseline by checking inrush current using commercial power while using a short 10-12 gauge extension cord. Once you've established this baseline, in the future it won't take long to isolate your start-up problems with the a/c unit, trailer wiring, RV extension cord, or generator.
