Windlass: low-side or high-side switching?

[LongRange]

My Quick 1500w windlass has been running great for many years. There is an up/down SPDT momentary switch in the cockpit, and a wired Quick remote in the lazarette.

I bought a typical fifty buck eBay wireless relay, soldered up a storm all excited, and took it up into the lazarette to wire in parallel with the existing two switches.

That is when I realised that my windlass is negative-switched, and thus incompatible with the wireless relay whose two outputs go to positive rail voltage when the buttons on the wireless remote are pressed

I do not like my chances of finding a wireless relay whose outputs are configurable to go to ground when the buttons are pressed. Instead, I am thinking of rewiring the contactor, so that it is high-side switched.

1) Is there a particular reason why a very standard 12V windlass should be low-switched? Convention? A safety aspect? The guy that did the original installation simply happened to grab the black wires first?

2) If the windlass should remain low-switched, can anyone recommend a wireless control that can cater for that?

Thanks for all info!

[GordMay]

Originally Posted by LongRange

... The guy that did the original installation simply happened to grab the black wires first? ...

I would hazard a WAG that "The guy that did the original installation simply happened to grab the black wires first".

[BobHorn]

If the wireless relays are really relays, why would they care if they switch the positive or negative wires?

[mjscottinnc]

Some basics, a relay is just a normally open (NO) switch -->/ <-- and/or normally closed (NC) -->_<-- switch. NO means when the relay is not energized no connection, NC is the opposite, connection at rest and the connection opens when energized. If you get positive voltage out of your remote either it was prewired before you got it (and may be changeable), or was internally permanently wired to + voltage.


If the existing wiring of the remote can not be changed, you can always add an additional relay to the output of the remote and then wire the windless control to the contacts of the additional relay. A +12 Volt DC control relay is easily found (think relay from an auto parts store. Try to get a sealed one, they are water proof). If that is the way you go, wire the output from the remote to the new relay coil (observing polarity if you bought a polarized relay), the other side of the coil to ground, and then the contacts of the new relay to your windless motor control contractor/relay.

[mjscottinnc]

Now about the wiring of the existing system.

In most worlds the positive voltage or hot voltage is switched or controlled. When you switch the ground side of things that means you have a live wire floating around and could potentially short out against something, which is easy in a body grounded car, somewhat less probably in a fiberglass boat. There is also a higher potential of electrolysis, if your hot wire conducts to a thru-hull. Boat owners are notorious for fixing things in an emergency and forgetting about it after the emergency is over. For example after purchasing my last boat I had a electrical wire which was hose clamped to a battery terminal. Ingenious in an emergency, but potentially a big problem. First thing I fixed!

I would fix the windless wiring, but then again I'm an electrical engineer with all the tools and knowledge to do the job.

Good luck

[stormalong]

Your remote is only switching a solenoid that activates the windlass - a light load circuit. It should be an easy rewire.

What BobHorn said is also true - Most of those controls that I have seen are relay output so you should be able to wire it for negative switching.

I would rewire to positive switching anyway because sometime in the future you or someone else is going to expect it to be that way.

[mvmojo]

Rewire the windlass so it switches the hot (positive) side. If you're not comfortable doing it (should be easy if you have any dc electrical experience), hire someone. Otherwise, as stated in an earlier post, you have a hot wire going to your windlass all the time. Any accidental contact can cause a dead short with full battery current flowing thru the short - it will weld the short & can cause a battery fire! Fix it properly! Also, make sure the solenoid(s) that control the windlass, if they are mechanical, are oriented such that if the internal spring fails the windlass will not turn on due to gravity. We had this happen to us on our boat due to PO installing the solenoid "upside down". The spring rusted and broke, contactor fell down to the points and the windlass came on with the anchor tight against the pulpit. It melted 30 feet of wire and almost started a fire on the boat.

[Matagorda]

Hi Long Range

FYI, in case it is of any help to you:

Quick make a couple of different types of wireless remote units.

See link below.

Wireless Remotes and Receivers - Accessories

I just installed one on my boat. It works great on my Quick 1000W windlass.

Not cheap though.

Cheers

Originally Posted by LongRange

My Quick 1500w windlass has been running great for many years. There is an up/down SPDT momentary switch in the cockpit, and a wired Quick remote in the lazarette.

I bought a typical fifty buck eBay wireless relay, soldered up a storm all excited, and took it up into the lazarette to wire in parallel with the existing two switches.

That is when I realised that my windlass is negative-switched, and thus incompatible with the wireless relay whose two outputs go to positive rail voltage when the buttons on the wireless remote are pressed

I do not like my chances of finding a wireless relay whose outputs are configurable to go to ground when the buttons are pressed. Instead, I am thinking of rewiring the contactor, so that it is high-side switched.

1) Is there a particular reason why a very standard 12V windlass should be low-switched? Convention? A safety aspect? The guy that did the original installation simply happened to grab the black wires first?

2) If the windlass should remain low-switched, can anyone recommend a wireless control that can cater for that?

Thanks for all info!

[mvmojo]

Been using this one for the past 5 years or so. Works great, transmits through the steel deck with no problem. $16.99 with two remotes.
https://www.amazon.com/LIEBMAYA-Wire...gateway&sr=8-5

[Jammer]

Originally Posted by LongRange

1) Is there a particular reason why a very standard 12V windlass should be low-switched? Convention? A safety aspect? The guy that did the original installation simply happened to grab the black wires first?

It eliminates the need to run a hot wire to the switch. I don't think that's good technique on a boat, but it's done on cars and trucks.

[stormalong]

Originally Posted by mvmojo

Rewire the windlass so it switches the hot (positive) side. If you're not comfortable doing it (should be easy if you have any dc electrical experience), hire someone. Otherwise, as stated in an earlier post, you have a hot wire going to your windlass all the time. Any accidental contact can cause a dead short with full battery current flowing thru the short - it will weld the short & can cause a battery fire! Fix it properly! Also, make sure the solenoid(s) that control the windlass, if they are mechanical, are oriented such that if the internal spring fails the windlass will not turn on due to gravity. We had this happen to us on our boat due to PO installing the solenoid "upside down". The spring rusted and broke, contactor fell down to the points and the windlass came on with the anchor tight against the pulpit. It melted 30 feet of wire and almost started a fire on the boat.

Sounds like you do not have an appropriately sized fuse or circuit breaker protecting your wiring and battery. You should remedy that.

[Dave_S]

Not sure why people chose to switch earth, a lot of the electronics people do it. For the reasons above I have always switched +ive.

I don't understand why your relay cares which one you are switching. If it is wired earth switching, I'd run the earth through the relay. You could check the +ive wire run to make sure it isn't at risk of a short.

[RaymondR]

Originally Posted by Dave_S

Not sure why people chose to switch earth, a lot of the electronics people do it. For the reasons above I have always switched +ive.

If you are switching electronically high current MOSFETs which switch the negative side are far more readily available and tend to be cheaper and are switched by a positive voltage to the gate terminal which tends to be more convenient to arrange in a lot of electronic circuits.