7 pin and shore power connection

Sharon_is_SAM

This unique question came up over on the TaG forum and I wanted to share it since I have not seen it discussed here.

Can you connect your RV to shore power and remain connected to the TV via the 7 pin?

I sent a message to Mike Sokol - RVTravel.net electric guru. He addressed 3 separate areas of RV/TV power regarding this issue.

He reported that the AC power is separated internally from the DC power via the converter - so no problems there.  

The running, tail, and brake lights are independent of the AC system in the RV, so no problems there.

And then there is the charge wire from the TV battery that charges the TaB battery via the 7 pin.  Whether or not you have an isolation relay on the TV to prevent the TaB battery from draining the TV battery, it is still safe "electrically" to have both a 7 pin and shore power connection.  But, without a relay, you risk the draw down of the TV battery or the possibility of the TaB converter actually charging the TV battery.  As a result "Charging circuits are very sensitive to battery chemistry and size, so intermixing your RV and Vehicle batteries, especially during charging, is a bad idea."

So, if you have an isolation relay, you can safely leave the RV hooked to shore power and to the TV via a 7 pin. If no isolation relay, disconnect from the TV while plugged into shore power.

davel4wa

Not something I would likely do as I would always disconnect whether towing a vehicle with a motorhome or a trailer with a tow vehicle. It's good information nonetheless and certainly something to think about.
When I provided a charging line from my motorhome to my towed Tacoma, I  added a self resetting circuit breaker and an isolation diode to the line in the Tacoma. For TVs that have a factory installed 'tow package' I assume that they include isolation if only in the form of a relay activated only when the TV is running.

Sharon_is_SAM

I agree-not something I would do either.