My generator is starting of its own volition. Although I admire its enthusiasm the noise is sometimes unwanted.

I have taken the lid off and everything looks fine. I have checked the remote switches and they also look fine. How can I test whether this is a software problem with the control unit (DDC in this case) or a short elsewhere?

I have attached the wiring diagram for the generator. Any help or advice would be welcome.

Thanks in advance.

 

Welcome to AAC!
If the remote is disconnected, does the problem still occur?
Is the generator exposed to damp conditions?

 

Thank you Alec_t

There is a remote and when not connected the problem (so far) seems to not continue. Thanks for answering my question!

This does indeed encounter damp conditions as it is on a boat.

Next question will be how to reprogram the remote

 

There is a remote and when not connected the problem (so far) seems to not continue.

That points to the problem being something in the remote (or its connections to the generator), rather than in the generator per se.

 

I have checked both sides of the cable and the connectors and both are clean without flaws. I guess this is a software problem in the remote but I struggle to see how it has just occurred now after many years of faultless service.

 

If the remote contains any electrolytic capacitors they are likely candidates for the source of the problem, since they tend to suffer from increased ESR and loss of capacitance as they age.
It's also possible that the pcb in the remote has absorbed moisture enough for the insulation between tracks to be compromised.

 

... I struggle to see how it has just occurred now after many years of faultless service.

To which my usual response is:

I've been going up and down this ladder for the past 20 years with nary a problem, why now it break?

 

Another thing to look for since it's on the water is corrosion, especially if it's salt water. Is there perhaps a remote start connected to a bilge pump water level switch?

 

Thanks for your enlightening input but after some further investigation the problem deepens.

The boat has two methods for AC current input. One for when the generator is running and one for when the boat is plugged into "shore" power. As you will see on the attached drawing there is a switch which differentiates between the two.

It appears that the the generator will only switch on and off by itself when the boat is plugged into shore power.

Baffling!

 

Can you post a clearer pic of the section you've highlighted?
Is it possible that shore power gets back into the generator via the change-over switch and runs the alternator as a motor?

 

Its an interesting point but why would it shut down again automatically?

I have turned the battery to the generator off whilst I am connected to shore power so this has temporarily solved the problem.

I have attached a close up.

 

Is that 'PC link' the remote control connection'? Perhaps interference on the shore power supply is getting through to it?
Is the problem a recent one? If so, can you identify any recent change in the boat's wiring etc ?

 

Do yourself a favor....get some long cable that you can hook up to DMM leads, and check to see if you have a solid Earth connection at both ends of the ship to shore connection. IN other words, check to see if you can measure voltage between the electrical reference/safety Earth wiring on the boat and the Earthing connection at the shore mains tap. If you have anything over a couple tenths of a volt between the two, you may have found your problem.