Reverse Polarity

[JPMyers]

Hi All.
I have a 1975 Marine Trader. Completely rebuilt 10 years ago. I have owned for 4 years. Duel 30 amp input. AC panel split in 3 busses. One 30 amp does buss 1 and 2. Other 30 amp does buss 3.
Everything works perfectly whether using both cords, one cord with the transfer switch on, or on generator.
Problem is, when I push the CHARGE button on the Heart Link 2000, buss 3 dies and I get a RP error code. When I turn off the charge button, power is restored to buss 3. Tried with all buss 3 breakers off. Same result.
Thoughts?

 

[SteveK]

Inverter neutrals have to be on a separate buss. That would be the first place to look, a neutral on the shore power buss. IMO

 

[O C Diver]

Buss 3 may be the inverter buss. Basically, there's likely a transfer switch in the inverter. When the inverter senses shore power or the generator, the transfer switch routes power from either to buss 3. When shore power or generator are disconnected, the transfer switch charges and directs the inverter to power buss 3.

I would check to see if you have a load on buss 3 that exceeds the 30 amp shore power when combined with the battery charger. If you turn off all the other breakers on buss 3, does that eliminate the problem?

Btw, I would have expected buss 2 to feed buss 3 through the inverter transfer switch. Are you sure that the breaker for the inverter isn't on buss 2.

Ted

 

[JPMyers]

Buss 3 may be the inverter buss. Basically, there's likely a transfer switch in the inverter. When the inverter senses shore power or the generator, the transfer switch routes power from either to buss 3. When shore power or generator are disconnected, the transfer switch charges and directs the inverter to power buss 3.

I would check to see if you have a load on buss 3 that exceeds the 30 amp shore power when combined with the battery charger. If you turn off all the other breakers on buss 3, does that eliminate the problem?

Btw, I would have expected buss 2 to feed buss 3 through the inverter transfer switch. Are you sure that the breaker for the inverter isn't on buss 2.

Ted

There is a manuel transfer switch on buss 3. It gets locked out when using the generator. I have a inverter/charger.
Using only one 30 amp cord I can energize the entire AC panel and run everything except the air conditioning.
When all buss 3 breakers are off, I still have the same problem.

 

[O C Diver]

On what buss are the circuits that are powered by the inverter?

Ted

 

[O C Diver]

Does the battery charger in the inverter work?

The loss of buss 3 when engaging the battery charger would indicate to me that buss 3 is being fed through the transfer switch within the inverter. My assumption would be something is malfunctioning in the inverter.

On my boat, everything that is fed off the inverter goes through the transfer switch, and is powered by the inverter battery charger circuit breaker. If yours is similar, I would find the circuit breaker for the inverter/battery charger and work your way to and through the inverter to buss 3.

Ted

 

[JPMyers]

Does the battery charger in the inverter work?

The loss of buss 3 when engaging the battery charger would indicate to me that buss 3 is being fed through the transfer switch within the inverter. My assumption would be something is malfunctioning in the inverter.

On my boat, everything that is fed off the inverter goes through the transfer switch, and is powered by the inverter battery charger circuit breaker. If yours is similar, I would find the circuit breaker for the inverter/battery charger and work your way to and through the inverter to buss 3.

Ted

According the schematic that came with the boat, the inverter only powers the frig and all ac receptacles. All of those are on buss 3. So 3 probably is energed through the transfer switch. Why do you think I still have the same problem when the transfer switch is off and 3 is energized with the second power cord?

 

[Fleming]

Sounds like your inverter/charger is not separating the neutral to ground connection when it is in charge mode. So you essentially have two neutral to ground connections when you are trying to use bus 3 with a shore power connection.

 

[O C Diver]

According the schematic that came with the boat, the inverter only powers the frig and all ac receptacles. All of those are on buss 3. So 3 probably is energed through the transfer switch. Why do you think I still have the same problem when the transfer switch is off and 3 is energized with the second power cord?

The transfer switch may have a center off (neither) position when the inverter/battery charger goes into error mode. In this case, a pilot circuit determines the transfer switch position. I would consult the manual to determine the above, and the error code. If you don't have the manual, they can often be available online, even if the manufacturer is out of business.

Ted

 

[JPMyers]

Thanks for your input. When I get back to the boat in a couple of days I'll try figure this out.

 

[Greg QS]

Is this a new problem or since you owned the boat?
Did you check for blown fuses? Most inverters have them inside. Reversed polarity can blow them... Many times the blown fuse is what triggers the light.