Is this 12V solenoid continuously rated?

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This 12V dc solenoid is part of my anchor windlass system and I am making a design change. At present it is only energised when the windlass is running but I want to keep it energised all the while the anchor power is enabled - which could be several days if I forget to turn the switch off.

Anchor_solenoid_web.jpg


Can anyone tell me whether the coil is continuously rated and if not, whether I can buy a replacement with a continuous coil, and where from?

I know it's tempting sometimes to ask "why would anyone want to do that...." but there is a good reason in this case but it would take a long post to explain!

Many thanks.
 
Re: Is this 12V solenoid continuously rated - probably not

Apologies not not giving a definitive answer, but would like to point out that that particular device would take quite a bit of current to energise the coil, so if it were left on permanently it would drain the batteries. I have in mind around 5 amps..

The reason is that you need a hefty closing power as the contacts are quite beefy for the anchor motor. Both the solenoid coil and the supply leads are quite beefy.

'Course I could be wrong...
 
Why would anyone want to do that? /forums/images/graemlins/smile.gif

Joking apart it does sound like a odd solution. I am never fond of these installations that constantly draw current when on (like most gas solenoids)
 
Looks like it is...

I know appearances can be deceptive, but your solenoid looks suspiciously like this one by Imtra, who describe it as "continuous duty".

However, I share the concerns expressed about current draw - this type of solenoid typically takes 2 or 3 amps.
 
Re: Looks like it is...

Why not just bolt the power cables to one terminal as you seem to want a permanent power feed ?
 
Re: Looks like it is...

That seems to be the one, thanks!

OK, guys, they say "curiosity killed the cat" but the Cat won't come to any harm at this time of night /forums/images/graemlins/grin.gif

I have a Lofrans windlass that is arranged with only 'up' control from a pneumatic switch mounted near the base of the windlass. Two heavy cables and the light pneumatic line go back from the windlass via a complex path to the power distribution board (see photo) and the instrument console. On the instrument console there is a switch that enables the anchor power - low power, of course. This switch is wire-anded with the output of the pneumatic switch and when both are enabled, a signal goes via a wire - along a difficult path - to the distribution board where it energises the solenoid.

So, we have one way control under the control of a single pneumatic switch by the windlass, that is enabled via a switch on the instrument console. I am changing the system so that I have radio control of up and down, using the Lofrans radio controller designed for the purpose, plus a Lofrans control box. I have already bought these parts so that part of the design is fixed. Since radio is involved, I want to be able to fall-back to the present arrangement at the flick of a single switch, should the radio control fail or fall overboard.

Now, we already have a heavy + and - cable going up to the windlass so we want to make use of those without running an extra heavy cable. Further, I don't want to make any more modifications than are needed, unless there is good reason. So I have chosen to mount the Lofrans control box (which takes + and - and provides M(up)+ M(down)+ under the control of two control wires, the control will be derived from the new radio system. This requires that the existing heavy cables are constantly energised when we are anchoring. Once we are finished, the power can go off again. This is controlled by the solenoid in the photo so I plan to add a low current switch which, when operated, energises the solenoid over-riding the original control. With the new switch off, the system (almost) reverts to the original. 'Almost' because the Lofrans control box is presently only getting a signal from the radio control. I shall add a light-current switch close to the control box such that the appropriate control pin is hard-wired to +ve. So, when we intend to operate the system in the original mode, I nip up to the anchor locker, and flick the switch over and do not switch the solenoid over-ride switch.

It's terribly difficult to write up a circuit description without reference to a circuit so I hope it made sense.

Anyway, the solenoid will seldom be energised for more than half an hour or so but if I forget to turn it off, which would only happen when motoring after bringing the anchor up since I monitor the current draw very closely when the engine is not running. In the worst case, I bring the anchor up and then motor for two or three days (yikes!, but it is possible if almost inconceivable!) and I don't want the risk of the solenoid burning out especially with the dc volts at 13.5V or 14.5V for so long.

Since I only ever use the windlass when the engine is running there is no shortage of power. The only problem is cooking the solenoid. I think I've got a spare solenoid in my spares box so I will energise the solenoid and keep a watch on the temperature with my IR thermometer then leave it running for a few days to prove the point. Not definitive but probably an acceptable 'proof' given pvb's link to Imtra, for which I am very grateful.

Thanks very much to all of you, chaps! /forums/images/graemlins/smile.gif
 
Re: Looks like it is...

Could I suggest a minor alteration? If you can either wire a flashing LED in parallel with the solenoid coil, or have it driven by the circuit that switches the solenoid on, and mount it somewhere eye catching, you'll have a reminder that it's been left on. I did this with my gas solenoid which I like to switch off as soon as possible since it draws a lot of current and it's worked quite well.
 
Re: Looks like it is...

Good idea. I was wondering whether to make up a little timer with piezo sounder on a bit of Veroboard, to bleep after, say, 30 mins then every 30 mins thereafter. LED would be easier, tho' as long as I can find a good place to mount it....which I can, I think. Thanks!
 
I'm really struggling with that website..sometimes it wants me to register and log on, sometimes it tells me the object has moved. Which product ID were you referring to? Many thanks for your help.
 
With a good quality multi meter you can check the current draw and also the temp rise from that you can asses if it would be wise to leave it on continuous.
I can not see any reason to want to leave a solenoid contactor on in a permanent energised state ( will just end in battery drain) other than on a mains supply.
Any peace of kit what ever the load can be switched though a 10ma or less solenoid. Or use it to drive a larger solenoid. but having said all this it is far better to have an open circuit and switch to operate any piece of kit.
 
You beat me to it:

http://www.colehersee.com/pdf/H-Relays.pdf

It is good not to have the whole of the long leads powered all the time. Is there no way to put the new control solenoids in place of this one and then with a relay DPCO make the new contactors work as though they were this simple one.

Basically it would all be wired up using the new remote but with the new contactors on the distribution board instead of next to the windlass.

Then cut the wires from the remote receiver to the new double solenoid and connect them through a DPCO relay (triggered from the foot switch) so that whenever the foot switch was used it would override whatever the remote was doing. I.e the up/down signals from the control box (solenoids)would each go to the common of the CO contacts. The normally closed contacts would go to the remote. The normally open contacts would be hard wired to cause the upward direction.

You would not need any mode switches or enables and it would be a lot safer and simpler!

I wish there was a quick way to do drawings. Explanations like this are too hard.
 
Re: Looks like it is...

Having read your detailed account. I see no probs just put the solenoid in a switched circuit. the radio will still switch the main solenoid (Contactor). If you are looking for a raise and lower operation then you will need to use Two solenoids as do "warn" with their remote and RC winches.
 
I thought I'd explained that it will not be powered up all the time, only during an anchoring phase so there is absolutely no problem with this at all. The issue of leaving it powered up for 24 hours or so is only if in error, by mistake, I forget to turn it off. It should never happen but if it does I don't want it to damage anything.

As for putting the contactor on the distribution board I would have to run a heavy lead all the way down the boat. This is a hugely disruptive and difficult task on a Nauticat already loaded with full liveaboard stuff (to do properly) and not a task that I would consider undertaking other than as part of a much wider package of work.
 
Thanks, I seem to be getting somewhere now...according to Colehersee their intermittent solenoids have a duty cycle of 10 seconds on and 20 minutes off. This would be totally inappropriate for an anchor windlass and it is a fair assumption that the continuous solenoid will have been fitted. Many thanks for the link. Funny website that, though, maybe it is my browser but it seems a bit unpredictable.
 
I must be missing something. There must already be 2 heavy wires going from the picture to the windlass. I assume the negative distribution is somewhere near the picture. If there are already 2 wires why would you need a third?

The new control box is just 2 solenoids that reverse the polarity on the output wires to the windlass. As long as the negative is some where near the distribution board, then this would be connected to the M- from the control box (solenoids).

Whatever you do, you are going to have to run new low power wires to supply the remote unit with power. Putting it closer to the distribution board and switch panel in general is better than running any cables all the way to the bow of a boat.
 
All the information is in my description. As I said, there are two heavy wires and one pneumatic line. The two heavy wires are one positive and one negative and they go straight across the motor. There are no contactors or electrical switches by the windlass. In order to reverse the windlass, we require three wires. One negative, one positive 'up' and one positive 'down'. This is essential. If I mounted the control box (which is actually the heavy duty relays) on the distribution board then I would have to run a heavy wire all the way along the boat to the bow. This is not what I want to do. Doing it my way there is no additional wiring run. Just a couple of very short jumpers in light wire and three short heavy leads around 1m long to wire the control box to the motor. Easy.
 
The penny has just dropped. Maybe my last explanation did not help as I did not understand the confusion. Our windlass requires three wires for reversing. i.e. we have one neutral and either the up or down terminal to 12V according to which way you want to go. I think you are thinking of reversing the motor just by reversing the polarity of the two wires? I don't know if that is ever done, but it is not the technique used by Lofrans.
 
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