Automatic Generator Start

This morning I was very pleased with myself because thegenerator started all by itself.  Lastnight I installed a little gadget for that purpose and it worked beautifully.

Starting the generator automatically has always been on theproject list, but seemed like a solution looking for a problem, so it nevermade it near the top.  It wasn’t until wemoved aboard and spent some time away from the dock and shore power that werealized that running the generator was an essential part of our power diet.  If nobody were here to start the thing, ourbatteries would die and the refrigeration would shut down.  It meant we couldn’t leave, and suddenly anautomatic generator start became more important.

Yes, we have a large solar array, no, it isn’t enough, andyes, our refrigeration is grossly inefficient. 
If we were going to be gone for a long period, we would probably throwaway all the food and turn the refrigerators off.  But if we only want to be gone for a fewdays, it’s better to keep everything running while we’re gone.

Another part of the problem was finding the right unit.  It is most common to find the generator startcapability as an optional add-on to higher-end inverters.  Our inverters have the capability, but notthe option, and they’re too old to find the necessary module.  Plus, different generators have differentstarting requirements, and we needed a unit that had the flexibility to start our Northern Lights.

It wasn’t until the project received priority that a searchin earnest began.  It yielded a few hits,but none as clearly perfect as the GSCM from Atkinson Electronics.  A call to the company had one on the way $249later.  Installing it was really no moredifficult than looking at the back of the Northern Lights’ control panel andwiring the GSCM to the appropriate switch contacts.

Most of these units are designed to work off battery voltageto determine when the generator is needed for charging.  I could do better since I have a VictronBMV-600 battery monitor that watches the Amps flowing in and out and calculatesa precise depth of discharge.  Thebattery monitor allows me to set thresholds at which it will energize a relay,perfect for signaling an automatic generator start if the unit supports it,which the GSCM does.  I will add a Flexchargeprogrammable timer to institute quiet times when the generator can’t run. 
Typically I only want it to run between 9 and11am, and when the battery is below 85%.

If air-conditioning were important, I could also use thetimer to make the generator start on an interval, or use a demand device like athermostat to start it.  But that getsback into solving a problem that I don’t really have.