Electromaax alternator with external regulator

[KeithP]

I am trying to complete/reinstate some charging upgrades started by the previous owner of our yacht. Its hard to tell how far they got because we had to get a contractor to gut the engine compartment, reline, replace seacocks, recondition the engine etc. So the wiring that is there now is what was in place after that work was completed.
The previous owner had installed an Electromaax 140 alternator which is wired through a battery isolator. Output was rubbish at 40amps max. Mounted on the side of the engine compartment but not connected are a Balmar Duocharge and MC-614 regulator. I have connected up the Duocharge and moved the alternator output direct to the house bank. Alternater output now doubled.
OK, long intro over, now trying to wire up the mc-614, but I am a little unsure of the wiring. I have run a sense wire for the mc-614 direct to the house bank. The alternator has a red sense wire connected direct to its positive out post, should this be left in place or disconnected? I am guessing disconnected but after much googling I can't find anything that clearly states this.

Any advice gratefully received before I complete the job.

 

[Bill Roosa]

The voltage sense should not be coming from the alternator if you are using an external regulator. The regulator will have its own voltage sense wire. That wire should be attached directly to the battery positive you are charging.
The voltage sense wire is connected to what on the other end? Clearly not the alternator as that would be really dumb, it it is connected to the batteries then it would short circuit the largeish power cable trying to connect the alternator to the batteries (without the interveining iso circuits making them also useless)

 

[Stu Jackson]

Alternator Regulator Wiring Diagrams - all three http://c34.org/bbs/index.php/topic,4548.0.html

My MC-612 is essentially the same as your 614.

 

[KeithP]

Stu, thanks for the wiring diagrams.

Bill, yes I have run a sense wire for the MC-614 direct to the battery bank. The alternator also has it's own sense wire, it comes from the side of the alternator and connects direct to the alternator +ve post. It is this that I was unclear whether to disconnect. Sounds like yes it should be disconnected and not used.

Cheers.

 

[Bill Roosa]

Only the regulator needs a sense wire. If the alternator has a sense wire it has an internal regulator and you want the internal one to be disabled. I'd be checking the output after it is all hucked up to make sure that with the alternator sense wire off the alternator is in fact being controled by the external regulator.