I've been using a Multiplus II 2x120v inverter/charger for over a year but have encountered a problem. When powering the Multiplus from a 120v inverter generator and programming the Multiplus to not draw more than 15 amps (at 120v) from the 'grid', the Multiplus will charge the 3 Battleborn GC3 batteries it's connected to just fine UNTIL I start a sizable load, like 15k BTU heat pump with a 'soft start'. The Multiplus then produces a 'L1 overload' code, which it never has before, begins inverting to power the load, and completely stops taking any power from the generator. The Power Assist feature is on but apparently isn't working properly. I've run the heat pump successfully this way before, but the temps outside have been around 100 F, and the Multiplus has been very warm but hasn't produced any temperature notifications.
I've tried the following already:
(1) reducing the max charging amps to 20 (only 240 watts),
(2) turning off the charging feature completely so that power from the generator would 'pass thru'
(3) turning off the Multiplus for at least 10 seconds before turning it back on.
In all instances, once I start my heat pump or air conditioner, the Multiplus produces the 'L1 overload' code, begins inverting to power the load, and stops taking any power from the generator. I've used the generator in this way to indirectly power the heat pump and avoid draining the batteries. But it seems that the 'Power Assist' feature just isn't working now.
Any ideas on how to fix this? Thanks in advance!