Voltage regulator hookups - how to

[Blueadventures]

Hi just chasing some info about a 12 volt voltage regulator issue for a mate.  Its not an aircraft engine application but any answers may be helpful for aviation engines in the future.

 

I was asked to have a look at a 12 regulator charge issue on a sail boat's inboard 'BUKH' engine.  What is happening is when he places the positive terminal spade to the regular it sparks.  He has no isolation switch in the circuit so the positive is live.

 

Would the regulator have a fault / short internally or should the positive feed be made open (disconnect positive from the battery or fit an isolation switch) when the positive feed is connected to the regulator.

 

Thanks in advance.

 

Mike

 

 

[facthunter]

 It's fairly normal to get a small spark as any relay needs a current to operate it. I'm presuming it's a mechanical regulator. Once the engine stops and the generator stops the relay should open or the battery would feed back into the generator.. There's lots of other possibilities of it's a permanent magnet generator or alternator and has diodes. Some alternators won't start charging unless "excited' by a DC current usually from the battery so a flat battery means you can't get that type of alternator to start  Nev.