what is this weird fuse on my windlass

[Brann-]

Hello all,
I'm replacing my windlass and I noticed this strange piece of hardware on the old one (see attached picture). It is marked with the following "63V- 1.50MKT 1,5/10 63V-"


The motor of the windlass has three pins (one ground, and two positives), and this thing was connecting them all together. The device is missing the ground connector which was linked to the slightly burned part (the motor ground terminator all but ignited at some point, hence the change of windlass)


My new windlass doesn't com with such a device, and nothing is mentioned in the installation instructions.

Does anyone know what it is, how it works, and whether I should install one on my new windlass ?

Thanks in advance !
Brann

[Lodesman]

That just looks like a heatshrink butt connector. I suspect the previous owned bodged it together for who-knows-what reason. It probably shouldn't have been that way - hence the fire. Just follow the install instructions that came with the new one.

[gulfstar37]

Dont think it fuses. Looks like cobbled up capacitors add on.

If new windless manufacture wanted it he would either send with windless or offer as a option.

[StuM]

It's two capacitors wired up in opposite directions and shrink wrapped. Certainly looks like a home made kludge.

[Wotname]

Originally Posted by StuM

It's two capacitors wired up in opposite directions and shrink wrapped. Certainly looks like a home made kludge.

Yep, two polarised electrolytic capacitors connected across the up / down terminals of the windlass with the burnt connector going to the ground lug.

Maybe to reduce some EMI but who knows????

[noelex 77]

Originally Posted by Brann-

Does anyone know what it is, how it works, and whether I should install one on my new windlass ?

As others have said, it is a couple of very dead capacitors. It was probably installed to reduce radio interference or something similar.

I would not install this on the new windlass.

[wingless]

The windlass motor draws a large amount current and the motor has a large amount of inductance.

When the motor turns off the inductance makes the current want to continue to flow, so that causes an inductive kick, causing the voltage to rise on the motor terminals.

Sometimes this voltage rises so high that it causes contact arcing on the electrical contactor used to supply / interrupt current to the motor.

The typical solution to this problem is proper placement of snubber diodes. The diodes create no current path during normal operation, but when the inductive kick happens the diodes direct that energy to dissipate harmlessly within the motor.

Agreed, the capacitors would have no beneficial effect on any motor operation. And, assuming the motor operates in both directions, the electrolytic capacitors would have the wrong polarity half the time, causing damage to the capacitors. Do not replace the capacitors.

[mrm]

Film capacitors (MKT) in general are not polarised. Other than that, as others stipulated, likely a snubber to reduce arcing / RFI.

[Wotname]

Originally Posted by mrm

Film capacitors (MKT) in general are not polarised. Other than that, as others stipulated, likely a snubber to reduce arcing / RFI.

Ahh... yes, I missed that - good spotting

[Brann-]

Thank you very much for your explanations, this is much clearer now.

In the end, would you recommend installing such a device on a newly purchased windlass, even though the documentation doesn't mention anything similar ?

Or is there a built-in mechanism in newly built motors to mitigate the arcing issue ?

Thanks !
Brann

[Wotname]

Originally Posted by Brann-

Thank you very much for your explanations, this is much clearer now.

In the end, would you recommend installing such a device on a newly purchased windlass, even though the documentation doesn't mention anything similar ?

Or is there a built-in mechanism in newly built motors to mitigate the arcing issue ?

Thanks !
Brann

If in doubt, follow the manufacturers documentation.

Repeat - follow the manual

The arcing issue affects the switch, not the motor; the motor windings cause the problem but it does't affect the motor. Good switch design minimises the issue.

[Brann-]

Well, I'm all for following the manual, but in this instance it's not that easily done.

I was planning on re-using my old 12v relay with my new 24v windlass, as this way I would have avoided re-wiring the whole control circuit.

I thought the relay wouldn't mind switching 24v instead of 12v as long as the intensity was equal or smaller.

Now, I'm wondering whether the brand-new power relay provided with my new windlass might have a built-in mechanism to achieve the same result as the contraption I removed from the old one.
I'll ask the manufacturer (Lofrans) and let you know the answer, if I ever get a reply.

Cheers,
Brann

[Adelie]

If the windlass comes with a relay, it is sure to be sized properly.

[Brann-]

Originally Posted by Adelie

If the windlass comes with a relay, it is sure to be sized properly.

I understand this. But since I've replaced my former 12v windlass by a 24v model of similar power (1500W), the current should be approximately halved, and the old relay should cope effortlessly, shouldn't it ?

[chris95040]

Originally Posted by Brann-

I understand this. But since I've replaced my former 12v windlass by a 24v model of similar power (1500W), the current should be approximately halved, and the old relay should cope effortlessly, shouldn't it ?

Obviously this depends entirely on the specification of the relay.