Buzzing relay Beta 43

[Tony Brooks]

13 hours ago, Detling said:

The control panel and probably the relay are powered by the starter battery not the domestic and this is charged by the smaller alternator which could be emitting AC. The domestic battery and inverter etc are powered by the bigger alternator and apart from the 0volt connection will be totally separate.

As with Sam, nice one, my mental picture of the circuit must have failed (again!!).

[Tony Brooks]

2 hours ago, system 4-50 said:

How much would an "adequate" oscilloscope cost these days?

Unless you wanted an instant alternators test it is unlikely to be worth buying one for amateur use where you usually have time to take measurements. A reliable clamp type multi-meter with a DC amps scale is, in my view, a far better investment. A failed diode will result in a reduction of both charging voltage and current so a s long as you know the normal "well charged battery" charging voltage and the alternator's rated output (Amps) you can assess the alternator by measuring the charging current with well discharged batteries and voltage with well charged batteries. It may be difficult to get the batteries near to fully charged on a single alternator boat with a faulty alternator but as long as it charges at above about 13.6 volts it will get there eventually. Its far easier on a twin alternator boat because a jump lead between both battery bank positives will allow the "good" alternator to charge both banks.

[cuthound]

1 hour ago, Tony Brooks said:

Unless you wanted an instant alternators test it is unlikely to be worth buying one for amateur use where you usually have time to take measurements. A reliable clamp type multi-meter with a DC amps scale is, in my view, a far better investment. A failed diode will result in a reduction of both charging voltage and current so a s long as you know the normal "well charged battery" charging voltage and the alternator's rated output (Amps) you can assess the alternator by measuring the charging current with well discharged batteries and voltage with well charged batteries. It may be difficult to get the batteries near to fully charged on a single alternator boat with a faulty alternator but as long as it charges at above about 13.6 volts it will get there eventually. Its far easier on a twin alternator boat because a jump lead between both battery bank positives will allow the "good" alternator to charge both banks.

 

Indeed, not much use for a 'scope on a boat, unless you want to check how "lumpy" the output of your inverter is.

[sbainbridge]

Thanks for the responses so far.

Both multiplug cleaned and connections remade, no difference

Ignition switch sprayed with WD40, suggestion from Beta Marine technical support.

Beta Marine technical support also sent annotated wiring diagrams for the affected area. I traced all the relevant wires and mine differ from those sent by Beta. I composed a long email with all the results to Beta together with photo's. Gmail in its infinite wisdom screwed it up, didn't send it and then lost it forever. Couldn't redo the email today as was travelling.

Having moved on the boat as a live aboard guess what I threw away when clearing the house out as it would never be needed on a boat?

Will get an electrician to look at both alternators when we get to the winter moorings marina. The buzzing relay is more of an irritant as it is something that should not happen, but it does not appear to have affected the charging.