Trojan Boat Forum

I have a new 1000 Watt pure sine wave inverter that automatically turns on when either shore power
or generator are not connected (it is not an inverter/charger)

I would like to have the battery charger (protech 1240i plus) automatically disconnect when the inverter kicks on
Currently I have to do it manually

I am wondering if I can connect a normally closed 120v ac relay to the output of the inverter and the input of the charger
This is above my pay grade so any thoughts are welcome

Thx
rr

Good question. First I would not like an inverter that comes on automatically. With the exception of running the refrigerator. What happens if it comes on, and the AC or microwave is on? At 1000 watts it can't power high loads and surly can not power all your electrical needs. Not sure how you have it wired in, but I would not have it wired to run the entire boat. How is it wired in?

I wired mine intentionally to do that. It has an internal transfer switch that kicks on when I cut shore power. I’m very intentional about having to turn off the charger breaker before I do that. I have the microwave, AC and water heater always off on my boat. I only turn it on when I need it.

I’d love some sort of automated process.

I thought about using the inverter/charger to charge my starting bank via an ACR and simply removing my existing canteen charger. Needless to say, I haven’t done that yet.

thanks guys

to answer prowlersfish's concerns
my inverter powers the entire boats 110v system and when on it's mostly used for fridge and tv
can't see a reasonable fear of it becoming accidentally overloaded in which case it would just shut itself down anyway
the automatic feature works fine for my needs

but like mr Z we seemingly have the same problem
that is having to turn off the charger as soon as the inverter is on
I think an inverter/charger solves this problem as long as it is the only charger involved
for me that is not the case as it is an inverter only

so hopefully someone can tell me if my relay idea is doable

The 2 powerboats I know of that have installed inverters do not have them wired into the entire boat. Wired mainly for the refrigerator. Sailboats are another story. I had one and I removed it and rely on shore power or the generator.

is there really only 1 AC circuit on the boat? My inverter feeds all the outlets on the port side only, to include my fridge and coffee pot, which are the only appliances on that circuit. An advantage being that once the alternator has completed the task of replacing the starting charge, my otherwise nearly idle alternator is keeping my beer cold on the way to my destination. In the morning I make coffee without disturbing the rest of the folks in the boat or in the anchorage, and the cream is still cold in the fridge. No generator use required.

fyi
With a little modification my plan worked
I installed a line voltage relay (normally open)
I powered it with the same a/c in of the inverter
One leg of the charger is interrupted by the relay
When connected to shore power or generator the relay closes and the charger is energized
When there is no shore power or generator the relay opens