Really weird electric issue

[ANarrowEscape]

1 minute ago, Tony Brooks said:

No problem, it can get difficult when topics wander about like this one has, from you question via the merits of turning the master switch and gas off when leaving the boat through domestic gas leaks to batteries gassing..

True. My original question really has got lost in here. It was a question about why my electric turned itself off when I wasn't there

I only mentioned having a gas sniffer to eliminate it from the question, as I've wired it to a different independent system. But the ownership of the dreaded gas sniffer has taken over, for some reason? I'd much rather have one than not, peace of mind and all that. 

 

[Tony Brooks]

Master switches have to have some kind of detent if they are rotary switches. The design of the indent varies but if its a spring loaded plunger/ball that rides over some kind of cam surface then I can imagine that if something prevented the switch turning through its full movement the "detent" might sit on top of the cam with the switch contacts closed. If this were the case (and I am not suggesting it is anything more than a long shot) then some expansion and contraction could move the detent enough to push on the wrong side of the cam surface and then it may well turn itself off by the spring pressure.

 

I suppose all you can do is to try to fabricate some form of temporary lock tab or lock wire to hold the switch key in the on position so if humans are involved they would have to bend the tab/wire.

[ANarrowEscape]

8 minutes ago, Tony Brooks said:

Master switches have to have some kind of detent if they are rotary switches. The design of the indent varies but if its a spring loaded plunger/ball that rides over some kind of cam surface then I can imagine that if something prevented the switch turning through its full movement the "detent" might sit on top of the cam with the switch contacts closed. If this were the case (and I am not suggesting it is anything more than a long shot) then some expansion and contraction could move the detent enough to push on the wrong side of the cam surface and then it may well turn itself off by the spring pressure.

 

I suppose all you can do is to try to fabricate some form of temporary lock tab or lock wire to hold the switch key in the on position so if humans are involved they would have to bend the tab/wire.

I think I'm going to get a video of the electrics and the switch in both positions. I'm not sure what it is off the top of my head. It looks like a red, almost heart shaped, switch. Don't think it clicks, but definitely has tension and can feel it switch off or on, with some force. 

Will do a video from my phone when I'm over tomorrow. 

[Slim]

15 hours ago, Alan de Enfield said:

 

Maybe beacause you are (possibly) almost unique in the wold of canal boats in having one.

I fall within the almost category as I have a gas sniffer. I fitted one as I came from the lumpy water brigade where they are almost always fitted. I turn it off when leaving the boat for any length of time. Going back to the original point I favour the dodgy switch school of thought.(unless I've missed something...quite possible)

[ANarrowEscape]

Found an image. 

So the issue is, when I leave the boat and return - might only be a day - the switch (which I thought tripped, but apparently can't) is turned off. 

[Tony Brooks]

Pull the red key out and very carefully inspect the little tab that sticks out of the "rod" It usually fits in a slot shaped like the slot on none side of a normal lamp bulb holder. I suspect that tab or the slot is damaged. I also suspect that you may find it not too difficult to pull the key out of the switch with it in the on position. Its only the tab that holds it in.

 

I would be loking to change that one for a decent quality one but they  are rather different.

[ANarrowEscape]

Just now, Tony Brooks said:

Pull the red key out and very carefully inspect the little tab that sticks out of the "rod" It usually fits in a slot shaped like the slot on none side of a normal lamp bulb holder. I suspect that tab or the slot is damaged. I also suspect that you may find it not too difficult to pull the key out of the switch with it in the on position. Its only the tab that holds it in.

 

I would be loking to change that one for a decent quality one but they  are rather different.

Okay will try it when I'm over. It never does it when I'm on-board, though? But will try anything right now. Also, yes, getting a new box and update soon. 

[Alan de Enfield]

It may be worthwhile changing the 'fuse box' as those torpedo fuses are the reason for many, many electrical (apparent) faults.

 

Take the fuses out, and clean the contacts in the fuse box and the fuses themselves.

[Tracy D'arth]

1 minute ago, Tony Brooks said:

Pull the red key out and very carefully inspect the little tab that sticks out of the "rod" It usually fits in a slot shaped like the slot on none side of a normal lamp bulb holder. I suspect that tab or the slot is damaged. I also suspect that you may find it not too difficult to pull the key out of the switch with it in the on position. Its only the tab that holds it in.

 

I would be loking to change that one for a decent quality one but they  are rather different.

The key should only come out in the off position, its an anti theft idea, no key, no electrics.

 

It cannot "trip", its purely mechanical.  Crap switches, cheap but failure prone.

[GUMPY]

When worn they do sometimes switch off when in use due to vibration. However that doesn't explain why it only happens when unoccupied.

[Chewbacka]

My only suggestion as to why it happens on an empty boat is that the switch is worn to the point it just holds itself ‘on’ until a cold night when the boat is not lived in, so the switch gets sufficiently cold it contracts enough to release.  On a warm boat it does not happen - yet.

[Momac]

I heard about faulty battery isolator switches years ago.

For that reason I leave mine on but that's easy for me since the boat is in a marina and on shore power.

 

Switch contacts and circuit breakers can become faulty. 

 

I suggest replacing the isolator  and perhaps look for a product with a high current rating (eg not one from Halfords)

 

[David Mack]

 

2 hours ago, ANarrowEscape said:

 

 

So your problem is exactly as identified by Tony early in the thread:

"BUT a typical red key job will eventually go faulty and appear to urn itself off although the key will still be in the on position. Try a ball of paper under the key or better still fit a decent quality master switch."

 

Those red key switches are crap. Replace it with something decent.

Edited December 27, 2020 by David Mack

[Tony Brooks]

I point out that @ANarrowEscape said that the switch (and key) had turned itself off, not that the key was in the on position but the switch was open circuit. That is why in my last post I dismissed the usually faulty switch contacts and went for the wear in the kkey/tap being sufficient for it to gradually work its way out, but time will tell when he gets to the boat and has a good look.

[ANarrowEscape]

21 minutes ago, David Mack said:

 

 

So your problem is exactly as identified by Tony early in the thread:

"BUT a typical red key job will eventually go faulty and appear to urn itself off although the key will still be in the on position. Try a ball of paper under the key or better still fit a decent quality master switch."

 

Those red key switches are crap. Replace it with something decent.

Thanks for the equipment advice. I intend to replace it.

As for the real problem, the physical key is in the off position when I go back to it. The photo shows the ON position. 

[MarkH2159]

19 hours ago, nicknorman said:

My point is that one should be very confident that the gas isn’t going to randomly start leaking, and if one is, there is no point in turning it off. The very act of repeatedly turning the gas tank on and off will increase the likelihood of leaks at the valve - that of course not really being a safety issue, but gas is expensive!

So...when you exchange/replace your gas bottles do you specify ones that have not had much use of the on/off valve, furthermore, how can you tell that the sup[plier is giving you what you need ?

 

As for the OP electrical issue, problem identified by Tony and others is a faulty Master Switch. There can be no 'tripping' due to any fault of the electrical system when using these 'red key' type of master switches.

 

Whether you choose to leave it on or off is also not the problem - Basically you need a new Master Switch.

[nicknorman]

1 hour ago, MarkH2159 said:

So...when you exchange/replace your gas bottles do you specify ones that have not had much use of the on/off valve, furthermore, how can you tell that the sup[plier is giving you what you need ?

 

Was that a rhetorical question?

When gas bottles get refilled they are subject to some checks, including to ensure the gas valve isn't leaking. So the less it is operated between refills, the less it is likely to wear and develop a leak. I agree that this is a tiny issue, but equally it is an even tinier issue that an unoccupied boat's gas system might suddenly and spontaneously decide to spring a leak.

[ANarrowEscape]

25 minutes ago, nicknorman said:

Was that a rhetorical question?

When gas bottles get refilled they are subject to some checks, including to ensure the gas valve isn't leaking. So the less it is operated between refills, the less it is likely to wear and develop a leak. I agree that this is a tiny issue, but equally it is an even tinier issue that an unoccupied boat's gas system might suddenly and spontaneously decide to spring a leak.

Question is, what difference does it make If I decided to leave the gas sniffer on or not? If the alarm doesn't go off and annoy the neighbors it makes no difference. I leave it on because, just like turning the gas on and off might eventually wear it out, the same principal applies to turning on and off electrical appliances - especially ones designed to stay on all the time. 

[ditchcrawler]

I was told that gas detection  has improved leaps and bounds in the past 20 years, I hope that is true as the ones we used offshore cost many times more than the ones used on boats and required a high level of maintenance to keep them working effectively. 

 

What does the alarm do if it detects gas?

[ANarrowEscape]

4 minutes ago, ditchcrawler said:

I was told that gas detection  has improved leaps and bounds in the past 20 years, I hope that is true as the ones we used offshore cost many times more than the ones used on boats and required a high level of maintenance to keep them working effectively. 

 

What does the alarm do if it detects gas?

It's only ever gone off once, but believe it was triggered with hairspray. It is an alarm, so makes an alarming noise. Like a smoke alarm, possibly a bit louder.

[ditchcrawler]

12 minutes ago, ANarrowEscape said:

It's only ever gone off once, but believe it was triggered with hairspray. It is an alarm, so makes an alarming noise. Like a smoke alarm, possibly a bit louder.

I just wondered if it tripped your electric ? or even shut the gas off.

[ANarrowEscape]

1 minute ago, ditchcrawler said:

I just wondered if it tripped your electric ? or even shut the gas off.

No, pretty standard alarm. Wish it did. 

[GUMPY]

35 minutes ago, ditchcrawler said:

What does the alarm do if it detects gas?

Mine makes a good awful racket, sensor is in the cupboard behind the cooker. 

Power is disconnected as it makes a god awful racket all the time.

[nicknorman]

2 hours ago, ANarrowEscape said:

Question is, what difference does it make If I decided to leave the gas sniffer on or not? If the alarm doesn't go off and annoy the neighbors it makes no difference. I leave it on because, just like turning the gas on and off might eventually wear it out, the same principal applies to turning on and off electrical appliances - especially ones designed to stay on all the time. 

None really, since it seems it won’t annoy the neighbours. I presume they have a key then, if you have an agreement that they would check out your boat if the alarm activates.

 

Maybe they also have a sense of humour?

[ANarrowEscape]

8 minutes ago, nicknorman said:

None really, since it seems it won’t annoy the neighbours. I presume they have a key then, if you have an agreement that they would check out your boat if the alarm activates.

 

Maybe they also have a sense of humour?

Yes they have a key. I know how this all relates to the OP, but not sure the relevance of my neighbors having a sense of humor fits, but I'm sure they do.