Flashing switchboard

[johnalison]

A couple of nights ago we were about to retire when I noticed that some of the lights on the switchboard were flashing, four or five flashes at a time and not their full brightness. Madam originally accused me of hallucinating, and then decided that the boat was about to burst into flames when the phenomenon was pointed out to her. I assured her that the current involved would be minute but my limited knowledge of electric circuits is too well known to her for my reassurance to have any effect.

So, I inspected the wires before turning off the battery isolating switch, when the flashes continued. Pulling out the mains lead also had no effect and the flashes stopped a few minutes later. As the switches involved were for those cables going up the mast, such as deck and steaming lights, I wonder if the cables were acting as a radio aerial, given that we were moored in a city, Groningen, at the time. Is this a well-known thing?

 

[Lon nan Gruagach]

A couple of nights ago we were about to retire when I noticed that some of the lights on the switchboard were flashing, four or five flashes at a time and not their full brightness. Madam originally accused me of hallucinating, and then decided that the boat was about to burst into flames when the phenomenon was pointed out to her. I assured her that the current involved would be minute but my limited knowledge of electric circuits is too well known to her for my reassurance to have any effect.

So, I inspected the wires before turning off the battery isolating switch, when the flashes continued. Pulling out the mains lead also had no effect and the flashes stopped a few minutes later. As the switches involved were for those cables going up the mast, such as deck and steaming lights, I wonder if the cables were acting as a radio aerial, given that we were moored in a city, Groningen, at the time. Is this a well-known thing?

I would think bit more than a city, radar perhaps.

 

[johnalison]

I would think bit more than a city, radar perhaps.

Maybe, though the timing of several quick flashes and a gap of five or ten seconds doesn't seem much like radar, and it was at about 10.30 pm in a city harbour.

 

[Deleted member 36384]

Aliens, abductions, tin foil hat territory, run!

 

[Serin]

Do you have a solar panel? I have discovered that in certain circumstances it is possible for our small one, which normally just trickle charges the engine battery, to keep feeding some milliamps into the system even when the batteries are switched off - if the negative is not quite rightly positioned. In my case it gave itself away by an occasional slow tick and turnover from the engine hour counter. Repositioning firmly to the negative bus cured the problem.

Here endeth the lesson from the person who knows the least about the ways of the electrons in the whole wide world!

 

[johnalison]

Do you have a solar panel? I have discovered that in certain circumstances it is possible for our small one, which normally just trickle charges the engine battery, to keep feeding some milliamps into the system even when the batteries are switched off - if the negative is not quite rightly positioned. In my case it gave itself away by an occasional slow tick and turnover from the engine hour counter. Repositioning firmly to the negative bus cured the problem.

Here endeth the lesson from the person who knows the least about the ways of the electrons in the whole wide world!

I always appreciate expert advice, however random. Yes, I do have a panel, and there was enough light for it to be charging, so maybe it was more 10 o'clock than later. The panel is connected directly to the service batteries, and would have been isolated with the batteries when I switched them off.

 

[nigelmercier]

Much more likely to be a connection up the mast shorting to the lamp common ground, and being blown by the wind.

Edit. Just noticed batteries off, so not that.

 

[GHA]

any insulated backstays nearby?

 

[johnalison]

Much more likely to be a connection up the mast shorting to the lamp common ground, and being blown by the wind.

I'm afraid you've lost me there. I am ignorant about how the lights are wired, since you imply that the masthead lights have individual positive wires and a single negative return (I suppose), which I would need to check to confirm. The lights were all functioning correctly. It had been raining but conditions were fairly quiet at the time.

 

[johnalison]

any insulated backstays nearby?

I'm blowed if I'm going back to look.

 

[GHA]

I'm blowed if I'm going back to look.

Does sound a bit similar to what happens when I email winlink with a ham radio for weather gribs and to log a position report, though more a sort of "rattling" of the leds than defined flashing, and not full brightness.

Usually in a port there's wifi or a mobile signal so no need to use a radio.

 

[Serin]

I always appreciate expert advice, however random. Yes, I do have a panel, and there was enough light for it to be charging, so maybe it was more 10 o'clock than later. The panel is connected directly to the service batteries, and would have been isolated with the batteries when I switched them off.

My panel was feeding the system with all the batteries switched off as well. I knew it must be the panel because the only way I could stop the feed to the engine hour counter was to disconnect the panel (the only other source of electrons I could think of) Switching off the batteries made no difference, as seems to be the case with your issue.

 

[bigwow]

Any alcohol involved?

 

[halcyon]

My panel was feeding the system with all the batteries switched off as well. I knew it must be the panel because the only way I could stop the feed to the engine hour counter was to disconnect the panel (the only other source of electrons I could think of) Switching off the batteries made no difference, as seems to be the case with your issue.

What is the panel ans exactly what is flashing ?

Brian

 

[William_H]

I have seen the LED indicators light up on a Beneteau when HF SSB was operated so I would suggest that in the dark it would not take too much power from a nearby boat (if there was one) to cause the effect you describe. I suggest you may never see it again. So don't worry olewill

 

[lw395]

Any mobile phones close to the panel?

 

[johnalison]

I have seen the LED indicators light up on a Beneteau when HF SSB was operated so I would suggest that in the dark it would not take too much power from a nearby boat (if there was one) to cause the effect you describe. I suggest you may never see it again. So don't worry olewill

Thanks. That's reassuring.

No nearby phones, and my panel is alcohol-free.

 

[Serin]

What is the panel ans exactly what is flashing ?

Brian

Small solar panel that normally feeds the starter battery. Nothing was flashing. Just the engine hour counter ticking away slowly. I suppose other parts of the system may have been getting a minute current as well, but not enough to activate them. I have no means of knowing. Now cured.

 

[PuffTheMagicDragon]

Is there a powerful radio transmitter in the vicinity?
Many years ago there was a Deutsche Welle relay station, around three miles from where I used to keep my boat for the summer. They had a huge array of 'aerials' that were selectively used to relay broadcasts towards different regions around the Mediterranean. At around 9 in the evening when, apparently, they used to transmit towards a different country strange things were noticed in the village. Car doors would suddenly unlock (especially Mercedes), alarms would go off, etc. All of these phenomena ceased when the station was shut down.