Shore Power/Genset breaker blowing

[andersonjames]

I have Hunter 45CC with Panda Mini8 Genset. The Genset runs the power on the boat fine at sea but when returned to dock the breaker on the Line 1, not Line 2 ( A/C Heat) blew. Traced wires checked invertor ( Fine) and when disconnected Genset at the AC box behind Seatee Seat we now have dock power with no issues. It seems like there should be a relay or something else between the genset and shore power that is shorting out. Any help on figuring this out would be appreciated.

 

[Snotter]

I have Hunter 45CC with Panda Mini8 Genset. The Genset runs the power on the boat fine at sea but when returned to dock the breaker on the Line 1, not Line 2 ( A/C Heat) blew. Traced wires checked invertor ( Fine) and when disconnected Genset at the AC box behind Seatee Seat we now have dock power with no issues. It seems like there should be a relay or something else between the genset and shore power that is shorting out. Any help on figuring this out would be appreciated.

There should be a transfer switch that both the shore power lines and genset lines go to. The house lines will also go to the transfer switch. It sounds like your transfer switch is blown.

 

[Jeff Jellick]

I have Hunter 45CC with Panda Mini8 Genset. The Genset runs the power on the boat fine at sea but when returned to dock the breaker on the Line 1, not Line 2 ( A/C Heat) blew. Traced wires checked invertor ( Fine) and when disconnected Genset at the AC box behind Seatee Seat we now have dock power with no issues. It seems like there should be a relay or something else between the genset and shore power that is shorting out. Any help on figuring this out would be appreciated.

Anderson,

I have a 2006 Hunter 45 CC with the same generator, Fischer Panda Mini 8. I am not sure what year your boat is. However I do not have the Shore Power Line 2 hooked up on my boat, as we do not have AC. There is a relay, actiually there are 11 relays in the 120-Volt AC Distribution Box that you refer to behind the Seat on the Port side. Two (2) of these relays control the incoming AC power from the generator, and are activacted by the small rocker switch on the "Hunter" panel located at the nav station.

When the generator is running and you have activated the rocker switch, it opens (or closes) these two relays allowing the generator to provide AC power to the 120-volt distribution panel. If the genertaor is not running, there is no incomming AC power from it to the panel, even if the rocker switch is in the "on" position.

The only thing I can think of is that the 2 generator relays inside the panel are bad, but I am not sure why this would cause the breaker to blow. I believe that you are refering to the breaker located in the aft cabin on the starbord side in the very rear of the cabin. I am also assuming that you do not have an AC selector switch on your boat, as there was not one on my boat

Over the years I had so much trouble with the relays that I replaced both the 120-volt AC, and the 12-volt DC Ultra Panels with a new Blue Sea panel. See attached photo. By the way the 12-volt DC panel (Ultra Panel) is also full of relays). Another problem with the original design was that Hunter did not install a 2-way, or 3-way selector switch that would only allow one (1) source of AC power to go to the 120-volt distribution panel at one time. Along with the new Blue Sea panel, I installed a 3-way Blue Sea selector switch that allows me to choose between either, Shore, Generator, or Inverter power to go to the distribution panel.

The Hunter manual that came with your boat has a wiring diagram of this panel, and shows all of the relays, and the two that control the generator power. Good Luck.

Jeff

 

[Sailvayu]

The breaker likely tripped because the neutral and ground are connected at the generator. These are not disconnected if the relay is not working right. Leave the generator disconnected on both the hot and neutral till you get this problem fixed as it could be a safety issue. I have never liked the auto relays, just one more thing to go wrong. Having to manually switch is not that hard and you know what is happening and what is or is not energized.

 

[andersonjames]

Thanks Jeff,

I was referring to the breakers in the aft stateroom. Thank you for your input. I had come to that same conclusion that my problem has to deal with the relays in the electrical box and will work on solving the issue. Thank you again for your time.

 

[andersonjames]

Thank your for your input. A manual swtching mechanism makes good sense as well

 

[Slipin Away]

manual switch

For a circuit diagram on how to wire the manual switch, see my post in the owners mods for the 45cc

 

[Snotter]

The manual switching is best, but could be the most expensive. If you have 50 amp service, a rotary switch that is capable of switching two shore lines will cost 300$ - 500$. On my boat I chose to build a relay box using 40amp triple pole, double throw relays that are fired by 12VDC coils. I bought 9 of the relays off of ebay from asia for very cheap. I designed the box so that it will facilitate maintainence. I suspect I will go through one or two relays a year. The relays last a long time if you remember not to activate the relays when current is going through them.