Hi, I’m new here, from Belgium, I’m in a project of a houseboat.
I have an offgrid setup with those :
Cerbo-S GX
Multiplus II 48/15000/200
MPPT 250/100
2 pylontech US5000 (atm. In the futur I’ll go up to at least 4).
12 Solar panels of 400Wc each on 3 groups of 4.
As said at the first line, i’m off-grid. I do have a diesel generator, a Lister Petter LPW3. I want to know if my multiplus could control that generator.
If I’ve read correctly, it is possible. Is that correct ?
If so, do I connect the aux relay directly on the alternator and on the stroke ?
I thought I had it saved on my phone but I can’t seem to find it now, it was a diagram I had found on this site a few months ago when I was looking into setting up my generator auto-start feature
Unless things have changed (or that generator is set up to accept an auto start input), you cannot do it directly from the inverter or cerbo, the relay that they use is just going to give you an on/off signal to work with. From this signal you need to use a relay to turn on the generator ignition circuit, and another one on a timer to operate the cranking circuit.
Do you have any information/diagrams on how the generator control panel is wired up right now? I’m assuming it’s just on a basic keyed ignition switch?
These are the chinesium timer relays I had bought for my project. These were to allow for the primer pump to run for x seconds then crank for x seconds (adjustable).
If that unit has glow plugs or an intake heater and if it doesn’t start very well without using them, you will have to use a similar setup with timer relays to allow it to preheat before cranking
Don’t take this for gospel, it’s just something I whipped up out of my head and assumes the current draw from the preheat and crank solenoids are within the limitations of the relay on the inverter/cerbo (whichever you choose to control it with) but this is basically what you’re looking at for wiring if you use these same relay
For the sake of safety I would highly recommend a lockout switch be worked into this so the engine can be safely worked on without risk of automatic start!
Edit: fudged up and had a feedback loop in the curcuit from the gen ignition. It still could use a diode on the preheat and start/crank wire as it is energizing the preheat relay while using the ignition preheat which powers up the preheat relay and the crank relay gets powered up when started with the ignition. but this should have no effect on operation as in either case the preheat relay will time out and reset itself and the crank relay will lose power when the ignition is returned to run state
I’ve not been well adviced from the guy who sold me the setup
And he left the company even before the delivery of my command.
He told me to choose between the M+ II 48/10000/100 and the 48/15000/200. Encouraging me for the second one “because which can do more, can do less. And you never know what you will need in the future”.
It’s a big unit. The battery has a 200a peak and 50a max operating near 80 odd amps for 1min. If the BMS starts alarming with over-current or over temp there are some settings to lower demand on them. See how you go, 2 more might get the full capacity. I think you might be able to get a stable 10,000W. It will be good to see how it performs and turns out.
Ok, wiring up the engine side won’t be bad at all depending what you need on the alternator and shutoff actuator.
The alternator will require a keyed power for the field excite wire
I’m assuming that’s a 3 wire fuel shutoff solenoid? The low amp hold coil winding will go to the keyed power source, the high current pull coil goes to the starter solenoid trigger wire
