I will be installing a multiplus 3000 with 3 100ah lithium batteries in my RV next week. I will usually be on shore power with occasional generator use and dry camping. Do I need a transfer switch with this set up?
(I will be adding 2 more batteries and solar later this year).
My opinion is 'yes'.
A manual on,off, on switch.
Place it so it (the changeover switch) gives you the choice of ...
1. generator in.
2. OFF
3. shore or external power in.
Other option in "no" & just plug whatever source in a 'power in' socket.
Depends if you have an inbuilt genny or not?
As BruceS says, a transfer switch may make it easier for you to switch between shore and generator power.
A manual switch goes one step beyond switching your shore power cable from pedestal and generator. But you would need to add a second inlet to the side of your RV.
To be truly useful, an automatic transfer switch would need to detect shore power and command the generator to start or stop based on that information. The value of such automatic control depends on your usage and how often you'd expect to change between shore and generator power.
Victron Venus devices do have a generator output that can start/stop the generator based on a number of conditions such as battery state of charge. However, it has no way of factoring in presence of shore power. So external start/stop logic would be needed so the generator doesn't run if shore power is present.
In addition, the Venus device may need to change it's parameters based on which AC source is feeding the Multi. So the state of the transfer switch (manual or automatic) would need to be communicated to Venus. Unfortunately, there is no such input available currently.
