Remote windlass wire size?

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Soundwiz

Veteran Member
Joined
Nov 26, 2012
Messages
53
Location
USA
Vessel Name
Spanish Moon
Vessel Make
Roughwater 44' Pilot House
I am running a new set of control lines from the windlass to the Pilot House.
The cable run will be 60'-75', from the windlass solenoids to a DPDT momentary switch in the Pilot House. I have checked the current wiring from the footswitch on the bow to the solenoids, and it is substantial, 10 or 8 AWG. Is this overkill for control lines? I was going to run 12/3 to the PH swittch, but now I'm thinking that may not be big enough for a run that long.
any thoughts, ideas or advice would be welcome.
Thanks
Dopp
 
Knowing the voltage 12 or 24 and the amperage would help answer the question.
 
The windlass is 12 volt.I don't know how much amperage the solenoids draw.
Thanks
 
Watts/amps draw of the windlass? Amps draw should show on ammeter when windlass operates. Or be in mfr operator instructions.
 
Last edited:
The windlass has a 100 amp fuse. I am not trying to operate the windlass motor. I am going to send control voltage to the solenoids which operate the motor. they are not fused and have no current rating visible to me. They look like automotive type starter solenoids.
Thanks for your help
Dopp
 
The windlass has a 100 amp fuse. I am not trying to operate the windlass motor. I am going to send control voltage to the solenoids which operate the motor. they are not fused and have no current rating visible to me. They look like automotive type starter solenoids.
Thanks for your help
Dopp

There should be a seperate fue for the control wiring. Use that value to calculate your wire size if you can't measure the actual current of the solenoid. Be sure to allow for voltage drop in the long length of wire.
 
I am the 5th owner of this boat and have found numerous things that "should be" that aren't. I am going to put a 30 amp fuse on the control side of the solenoids, and upgrade the control wire gauge to AWG 8. that sould be enough to keep the voltage loss to a minimum.
Thanks for your help
Dopp
 
The windlass required BIG power in order to operate.

The solenoids , if given a slight undervoltage will operate just fine.

Most 12V units will still pull at about 10V , and your 12Ga will be not lowering the voltage that much.

If you worry Cole Hersee sells latching solenoids , that only require a pulse to set or unset them,.
 
........... I am going to put a 30 amp fuse on the control side of the solenoids, and upgrade the control wire gauge to AWG 8. that sould be enough to keep the voltage loss to a minimum.

While there's no harm in using larger wire than necessary, I wouldn't use a 30 amp fuse in this circuit. I've posted many times that the fuse is there to protect the circuit, not the device, but in some cases, it protects both.

Suppose the solenoid has a maximum current draw of five amps and something happens to the solenoid where it doesn't engage. With thirty amps at twelve volts available, it may overheat and possibly catch fire.

Look for a label on the solenoid, contact the manufacturer, match it to one in a catalog that shows the current consumption, or just measure the current that flows through it when it is operated. Let's say the current is five amps. Your fuse should be 7.5 amps or 10 amps, no more. The wire can still have a larger capacity, that's fine.

As for voltage drop and operating at a lower voltage than designed for, you want a good, solid operation of the solenoid so the switch contacts are firmly engaged. Anything less and they may chatter, arc, and burn to where the solenoid must be replaced.
 
Ohm's Law - Volts = Amps x Resistance or Amps = Volts divided by Resistance

Take a volt/ohm meter and measure the resistance in ohms of just the solenoid coil you want to activate. Use the nominal voltage of 12 used to activate the solenoid and divide it by the ohm reading you get.
That will give you the amperage for the solenoid.
Use one of the many online DC wire sizing charts or calculators for wire size and use the appropriate fuse for the wire size used.
Wire sizing calculator for Solar Panel Arrays
 
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