Inverter Bypass

[Challo]

I have Xantrex Freedom inverter/charger. Blew the controller for the fan and it was overheating. Getting it repaired, but in the meantime did not want to charge the batteries using the engine only, so I bought a separate charger, which I have installed. Of course, this means I am without the inverter, which is really no sweat. The problem I have is that my AC goes through the inverter and since it is removed, I cannot use the AC unless I wire the input and output together, which I don't really want to do since I will just have to cut it back out when I reinstall the original unit.

Thinking down the road, I plan on keeping the charger as a backup for similar situations. What I would like to do, which will help me now and if this ever happens again, is to put in a selector switch so that I can run the shore power either directly to my panel or through the inverter. If I remove the inverter, I switch the shore power to go directly to the panel; otherwise, it just transfers through the inverter as usual. I am not talking about an INPUT selector switch, but an OUTPUT selector switch. I've seen threads that confuse this point and I have found lots of INPUT selectors (e.g., Gen vs Shore); the other way around is not as common, apparently.

Thanks for the help,

Challo

[Viking Sailor]

What I did was to put female AC connector on the output of the inverter and another female on the AC input from the dock. The panel has a male connector on a cord that reaches both the dock AC and the inverter AC. No switch just plugin to the desired AC source. Very cheap and fool proof.

[smac999]

I ended up having to design and build my own. nothing on the market worked for what I wanted. there were some on the market (and some designs I've seen on other boats) that would switch the shore to the inverter output but didn't kill the power going to the inverter. (so it was still live you wanted to remove it...) it was a blue sea double throw quad pole switch. (it's a gen / shore switch designed for 240v but just relabel it) but don't have part number handy. I also added the inverter output breaker between inverter and switch. in pic 2 but not in diagram.




square on the right is main AC panel with 30a inverter breaker.


it's probably around $300+ in parts which is why it's probably not common. (the switch wasn't cheap!) proably cheaper direct from switch maker and not from blue sea though

[Challo]

Originally Posted by Viking Sailor

What I did was to put female AC connector on the output of the inverter and another female on the AC input from the dock. The panel has a male connector on a cord that reaches both the dock AC and the inverter AC. No switch just plugin to the desired AC source. Very cheap and fool proof.

I thought of something like this -- essentially "plugging in" one or the other but I was concerned about the 30 amp circuit. I've had arcing even with the locking connections for the shore power. I think I'd be more comfortable with something hard wired and shrink wrapped.

[Viking Sailor]

Originally Posted by Challo

I thought of something like this -- essentially "plugging in" one or the other but I was concerned about the 30 amp circuit. I've had arcing even with the locking connections for the shore power. I think I'd be more comfortable with something hard wired and shrink wrapped.

I assumed that you would use the correct sized connectors. RV connectors are less then marine connectors. I get mine at Home Depot.

[Challo]

Originally Posted by Viking Sailor

I assumed that you would use the correct sized connectors. RV connectors are less then marine connectors. I get mine at Home Depot.

Thanks. I will look -- not sure what is available.

[Andina Marie]

You can avoid the cost of that double pole 2 position switch.

I faced a similar problem and solved it by using a small domestic breaker box. You use the two "input" bus bars of the box as your "output" and use 2 double pole breakers as the inputs. In my case I used 4 double pole input breakers to add the two gensets as additional supply sources.

The RULE is only one switch can be on at a time but since you are using breakers for the switching, if you make a mistake it corrects itself in 10 milliseconds!

[Challo]

Thanks to everyone for the replies. I got some advice offline from a friend of mine who is in the electrical parts business. His solution was quite elegant and obvious in retrospect. He suggests simply purchasing a dual source selector switch and running it backwards -- the electricity does not care which way it goes. So the single output becomes the single input and the dual inputs become dual outputs. The switch would just need to be relabeled. Any thoughts on this?

[socaldmax]

Sounds simple enough.

[Colin A]

As mentioned a source selector switch (rotary) would work just wired in reverse(just make sure it's wired correctly and relabel it). You can also use interlocked breakers and move the jumpers from the output to the input. Pretty simple either way. We have built a number of inverter bypass panels over the years.

[smac999]

Originally Posted by Challo

Thanks to everyone for the replies. I got some advice offline from a friend of mine who is in the electrical parts business. His solution was quite elegant and obvious in retrospect. He suggests simply purchasing a dual source selector switch and running it backwards -- the electricity does not care which way it goes. So the single output becomes the single input and the dual inputs become dual outputs. The switch would just need to be relabeled. Any thoughts on this?

But you'd have 2 inputs and one out out... You have inverter output (input to switch) and shore power input to switch. Selecting which one powers your inverter loads. So it's just run normally. You can also do this with a dual breaker system like a Bluesea gen / Shore double pole setup with interlock

However you still have ac power feeding the inverter. A live wire if you need to remove inverter / charger.

To get around this you now need two 30a breakers at ac panel with double 10/3 feeds one to feed inverter and one to feed bypass circuit. In the event of inverter fail you now have 2 steps. Turn on bypass switch (normally near inverter) and then turn off inverter breaker.At ac panel Bypass one can always be on.