Circuit breaker for a Lofrans Falkon

[sailing_gal]

I recently replaced a vertical Simpson Lawrence 1500 windlass with a Lofrans Falkon (I believe in solid, heavy duty ground tackle). The SL 1500 had a 70 A breaker which I have left in place. The local engineering advice I got said it would do fine. However, upon double checking the instructions, the Lofrans manual suggests a 125A breaker for a 12V system for the Lofrans and a 70A breaker if I had a 24V system. I have a 12V system. The windlass appears to be working just fine, I have not blown the circuit while operating it.

So, my question, is there any reason that I should upgrade that breaker?

[JBPohle]

I have the same windlass though a bit older. I’d use their recommended size, PROVIDED that the wire size can handle that ampacity. I’ve found that when heavily loaded/locked it will trip my 150 amp breaker that came with this boat. Also check your switch or solenoids to ensure they can handle the wattage of your new windlass.

[sailing_gal]

Thanks, John,

I have extremely heavy wire going to the windlass (#2, as I recall- not on the boat now), so I don't think it would excessively heat up. I am using the solenoid that came with the Falkon. So, I do not worry about the solenoid or wiring.

[Pelagic]

Originally Posted by sailing_gal

So, my question, is there any reason that I should upgrade that breaker?

I would change it.

You went with a much heavier lift windlass to give you additional break away torque if ground tackle became stuck.

By limiting breaker to 70a rather than the specified 125a, the breaker may pop before the windless reaches its potential...if you find yourself in a jammed situation.

I have the Lofrans Titan Horizontal which is wired from heavy duty buss bars to a dedicated on/off switch then the recommended fuse (200a @ 24v in my case) then solenoid then windlass motor.

The Windlass breaker is used only to power the control solenoid.

[boatman12]

The cable size is the key here. Look at the cable, get the size and then use the tables on the internet or the West Marine catalog to determine the maximum current for that sized wire. Choose the breaker size to not overload the cable or the manufacturer's recommended size, whichever is smaller.

Don't use a 125 amp breaker if the cable can only handle 100 amps.

[boatman12]

Originally Posted by Pelagic

.............. The Windlass breaker is used only to power the control solenoid.

That is incorrect.

[SVTatia]

The breaker is there to protect the cable.
I am not an expert but on a 42 foot boat, let's say the distance to the windlass is 30 feet and @ 10% loss, the #2 cable is only good for 120 amps.

[Pelagic]

Originally Posted by boatman12

That is incorrect.

In my case that is how it is done Boatie

[Cadence]

Originally Posted by Pelagic

In my case that is how it is done Boatie

Sounds as though there is confusion between the breaker and the fuse. Breaker for the solenoid and fuse for the winch's actual supply?

[boatman12]

Originally Posted by Cadence

Sounds as though there is confusion between the breaker and the fuse. Breaker for the solenoid and fuse for the winch's actual supply?

It could be either way. In my case, there is a 7 amp fuse for the wire feeding the solenoid coil and a 60 amp (or so) circuit breaker for the actual power to the windlass (which flows through the contacts of the solenoid)

[Cadence]

Originally Posted by boatman12

It could be either way. In my case, there is a 7 amp fuse for the wire feeding the solenoid coil and a 60 amp (or so) circuit breaker for the actual power to the windlass (which flows through the contacts of the solenoid)

It could be either but I doubt he has a 200A fuse protecting a relay or contactor at that amperage draw of the winch. I know relay/contactor is semantics.

[Pelagic]

Originally Posted by Cadence

It could be either but I doubt he has a 200A fuse protecting a relay or contactor at that amperage draw of the winch. I know relay/contactor is semantics.

Hi Cadence,

To clarify, the heavy duty fuse is only there to protect the heavy cable runs to windlass and Thruster.

Here are some old pictures before my complete ER refit which shows the 24V supply to Bow Thruster and Windlass.

Not exactly sure rating of 24V Fuse, but it is heavy duty. I would need to check spares list to confirm amperage, but when I relocated switches and fuses outside ER and into electrical closet, I thought it was 200a??

The 2 BEP switches on Left side are Emergency Parallel and Main Engine Start, that supplied the heavy duty fuse for either the Thruster or Windlass.

In the closeup, you can see the light (white cable) that energizes the Windlass Solenoid that is fed by 10a Windlass breaker on DC Panel. (same wiring for Bow Thruster)

Suggestion I was making to OP who has now installed a heavier draw windlass, is to install a separate on/off switch (like my BEP) and in line Fuse (as I have) to replace his under rated breaker.

The key thing as Boatie warns, is to first make sure his old wiring run is properly rated for the new windlass

[sailing_gal]

Thanks for lots of information- here is some clarification----- I am not talking about the fuse protecting the solenoid, I am talking about the circuit breaker- which apparently is protecting the wiring- which is battery cable sized (I think that is #2), plenty heavy. I am thinking that with the size of the cable, it would take a really long time for that wire to get hot enough to trip a 70A breaker.

[Pelagic]

Others can probably say it better, but an increased demand from your motor over a hard and long pull can trip an under rated breaker.

Not a big deal since you can reset it quickly and then haul up in short stages.....
As long as your convinced your cable is big enough.

I guess closely monitoring it is what you will probably do for now

[Paul L]

Originally Posted by sailing_gal

Thanks for lots of information- here is some clarification----- I am not talking about the fuse protecting the solenoid, I am talking about the circuit breaker- which apparently is protecting the wiring- which is battery cable sized (I think that is #2), plenty heavy. I am thinking that with the size of the cable, it would take a really long time for that wire to get hot enough to trip a 70A breaker.

The breaker does measure or trip based on the cable temperature. It trips based on the current passing through the breaker. So if the windlass motor draws in excess of the breaker rating for a period the breaker will trip.