Battery Bank Combiner Wiring or Charging House Batteries w/ Alternator

[DavidInWilmNC]

The post earlier about combining / isolating house and start batteries got me wondering.  Where's the best place to pick up 24v when the alternator is charging?  I know that the HVAC system doesn't operate 'til the 'not gen' lite is off, so I suppose there is a terminal in the HVAC breaker box in the front bay (I have a MC-8).  My combiner solenoid is located in this bay, so it would be a good place for me to pick up the signal.  I also need a connection that is 24v when the run-off switch is on.  I have an Intellitec latching relay to allow me to disconnect my start batteries, similar to the main disconnectg in the original battery bay.  I want to disable the ability to disconnect the batteries when the engine is running to prevent damaging the alternator.  Is there also a terminal in the HVAC breaker box that will give me 24v when the engine switch is on?  Thanks for any help.

David

[DavidInWilmNC]

I'm sure I'm not the only one who's connected an isolator/ combiner before!  Where did you guys who did connect the solenoid to allow it to be activated only when the alternator is charging?

[pvcces]

David, I answered this on the other board. I think you ought to look at the safety relay. It disables the starter when the generator is running and enables the operation of the HVAC system.

It uses the relay terminal output on the generator, which is about half the charging voltage.

For what it's worth.

Tom Caffrey

[Stan]

You have two separate questions.  Follow the wiring diagram from the R terminal through the rear junction box relay  contacts to the front junction box.. From the terminal there. it goes to the A/C switch. If you have removed the central A/C system there are lots of spare wires between the front junction box and the A/C control box.

On your second question I see two problems. If the relay is open (bus parked) where do you get the voltage to turn it on? Are you aware that this relay has to have contacts that will carry at least 600 amps? A cold starter on a cold morning will draw at least that amount of current before the engine starts to crank.