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Engine stop solenoid


Smelly

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The title says it all really...

 

I'm moving ahead with my failsafe engine malarky and am curious as to whether a 10A relay will be sufficient to pull in the solenoid, or whether I'd need to use it to close a 40A relay.

 

I'll post a circuit diagram of the setup in the next couple of days for anyone who's interested.

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The title says it all really...

 

I'm moving ahead with my failsafe engine malarky and am curious as to whether a 10A relay will be sufficient to pull in the solenoid, or whether I'd need to use it to close a 40A relay.

 

I'll post a circuit diagram of the setup in the next couple of days for anyone who's interested.

 

Just tested a 12v stop relay with my cheapo multimeter and it draws 0.85 amps unloaded.

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Just tested a 12v stop relay with my cheapo multimeter and it draws 0.85 amps unloaded.

 

Thank you... However, stop relay?

 

I might follow your lead and dismantle the connections however I wondered whether anyone might know off the top of their heads.

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Thank you... However, stop relay?

 

I might follow your lead and dismantle the connections however I wondered whether anyone might know off the top of their heads.

 

 

10 odd watts into any relay would suggest to me its a pretty big relay or runs very intermittently for short periods ! ( or cheap and nasty) :lol:

 

I have a soldering iron that consumes that sort of power !!

 

Nick

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Short Action Solenoids (starter engage & stop solenoids which only activate to

stop the engine) may well have only a single coil & therefore draw a high

current - intended for "brief" use only, any solenoid designed for longer duty

cycles should actually have two coils or some arrangement which presents

two coils - one high current "activation" and one lower current "hold in" coil,

along with an auxiliary contact which switches to the "hold in" coil once the

solenoid has thrown. I would assume that stop solenoids which are active

all the time an engine is running (i.e. a "permit run" solenoid really) should

be of this design. Of course this doesn't necessarily mean thats what has been

done in practice - it will also depend on the force the solenoid needs to apply

to achieve its intended action.

 

springy

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Our stop solenoid engages when we hit the stop button (permit stop?) only; or if it shorts as has happened.

 

It's been said elsewhere when I came up with my fail safe idea that in a marine application you want to minimise things that can go wrong and stop the engine unexpectedly hence the "permit run" model is unlikely. I've designed in a couple of switches to present quite a steep hurdle to accidentally engaging the fail safe while under way...

 

I am quietly surprised that a solenoid only draws around 10 watts, however if I'm using a 10A relay that should hopefully be enough.

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Our stop solenoid engages when we hit the stop button (permit stop?) only; or if it shorts as has happened.

 

It's been said elsewhere when I came up with my fail safe idea that in a marine application you want to minimise things that can go wrong and stop the engine unexpectedly hence the "permit run" model is unlikely. I've designed in a couple of switches to present quite a steep hurdle to accidentally engaging the fail safe while under lphaway...

 

I am quietly surprised that a solenoid only draws around 10 watts, however if I'm using a 10A relay that should hopefully be enough.

 

Just to add it's an energise to run engine solenoid from a Lister Petter Alpha Canal Star so it doesn't appear to be momentary.

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Just to add it's an energise to run engine solenoid from a Lister Petter Alpha Canal Star so it doesn't appear to be momentary.

 

Ah well, looks like I'm going to be dismantling things then... It surprises me that it's energise to run though...

 

Cheers again...

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Short Action Solenoids (starter engage & stop solenoids which only activate to

stop the engine) may well have only a single coil & therefore draw a high

current - intended for "brief" use only, any solenoid designed for longer duty

cycles should actually have two coils or some arrangement which presents

two coils - one high current "activation" and one lower current "hold in" coil,

along with an auxiliary contact which switches to the "hold in" coil once the

solenoid has thrown. I would assume that stop solenoids which are active

all the time an engine is running (i.e. a "permit run" solenoid really) should

be of this design. Of course this doesn't necessarily mean thats what has been

done in practice - it will also depend on the force the solenoid needs to apply

to achieve its intended action.

 

springy

I love you!

I have been going on about pull in and hold in coils (mostly on starters) for ages to a chorus of silence.

 

Sprag the solenoid so that it cannot complete its stroke and BRIEFLY power it up through an ammeter. It could easily be pulling 30A when initially engaged.

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I have been going on about pull in and hold in coils (mostly on starters) for ages to a chorus of silence.

That doesn't mean that people aren't listening. The chorus is invariably the sound of the silent majority, standing in awe at your depth & breadth of knowledge.

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This issue has been raised a couple of times previously.. It comes down to what comprises a fail safe system, for example an incident happened on my marina, a young chap was rolling some Tarmac on one of the pathways when the machine dropped into a ditch and it fell on it's side, to stop the engine it was only necessary to switch of the battery supply and no harm was done, many road vehicle now have an 'inertia switch', it's sole purpose to cut off the electrical supply in the event of a prang.

 

On a boat things are very different, there must never be any systems that will arbitrarily switch off the engine, even if damage could possibly result, you may not consider it to be vital on a canal boat but with other craft a functioning engine is important to the point of being life saving.. The very last thing you want to happen is for the engine to splutter to a stop just because the electrics have been swamped and that's what would happen if a 'power to run' solenoid was used.

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This issue has been raised a couple of times previously.. It comes down to what comprises a fail safe system, for example an incident happened on my marina, a young chap was rolling some Tarmac on one of the pathways when the machine dropped into a ditch and it fell on it's side, to stop the engine it was only necessary to switch of the battery supply and no harm was done, many road vehicle now have an 'inertia switch', it's sole purpose to cut off the electrical supply in the event of a prang.

 

On a boat things are very different, there must never be any systems that will arbitrarily switch off the engine, even if damage could possibly result, you may not consider it to be vital on a canal boat but with other craft a functioning engine is important to the point of being life saving.. The very last thing you want to happen is for the engine to splutter to a stop just because the electrics have been swamped and that's what would happen if a 'power to run' solenoid was used.

 

 

That's why I replaced mine with a manual pull to stop. Handy as well for cranking engine to prime with oil after a service.

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