TxCoastie

This is a great thread and appeciate all of your insights here.

Im running the Engo 9000lbs winch. FLA shows 340.

Will this is setup above be ok for my winch?

Thanks

Mr.T

Yep, the Bussman / BlueSea 200A breaker in the first post should work well. The key point is that the winch motor FLA rating is only for a short time period before it overheats, and it will overheat at significantly lower than FLA as well -- Winch motors are made for short term intermittent duty, like a starter motor. This type of inverse time delay breaker has a similar tripping characteristic.

Excerpt from the first post:

Rednroll

I'm late to the party on this one. I tend to get confused with circuit breaker ratings and fuses for that matter. If the voltage rating on them is the same as your application then everything makes sense.

So where I'm going with this....when I look at the circuit breaker it shows 48V/200A stamped on it. According to your tests you had done a pull which was averaging 220A. Trying to understand the reason the breaker didn't pop at that point due to the 200A rating on it.

I haven't read this entire discussion but did pick up on where you said the specs show it should trip around 400A once it is drawing 400A for a 25sec duration.

I'm trying make sense of all this. For me and electricity, many things boil down to "power" when it comes to ratings. Using the 48V/200A, stamp on the device, that comes out to 9600Watts. So now you're using this circuit breaker in a 12Volt application system, when engine running we'll call it 14V. Would that now mean this circuit breaker has a 685A rating for a vehicle application? 9600W/14V=685A

Mr.T

Fuses and breakers trip on amperage rather than the power consumed by the circuit loads. There is a small but measurable voltage drop across a fuse/breaker, and that voltage drop times the amperage is power to melt a fuse or heat a breaker's heater element-- but it's not affected by the circuit voltage.

The voltage rating of a fuse/breaker is a maximum design limit, what voltage the device can successfully interrupt without failing from arcing, overheating, etc. For example, it takes a much more substantial design to break a 120 vdc circuit at 5 amps than the same amps at 12 vdc.

Rednroll

Thanks! Now this is where I seemed to be confused.



If the breaker has a 200A rating stamped on it, I'm struggling to understand why it's not tripping at anything below 230 Amps?


I really like this idea of using a breaker. I currently have a fuse installed which came with my winch but the reason I never looked further into installing a breaker was that it was too difficult trying to figure out the proper size amperage rating without doing some trial and error. I have a 12K winch, I would have originally thought a breaker rated at 200A would have been too low but from what you've described and have shown, that doesn't seem to be the case.

Mr.T

Good question, this can be a really deep subject. It's a bit out of my lane, but here's my simplified explanation: 230/200 = 1.15 == 115%, which gives some room for running without nuisance trips a full 200A plus the typical errors including short periods of over current, which is especially common with motors.

Behind the nominal rating is always a trip curve that shows how far above the nominal rating is the trip for a given time at that amperage.

Did a quick search and these links have some details -- Great bedtime reading...

https://testguy.net/content/197-Char...d-Coordination

http://www.cooperindustries.com/cont...ow_to_Read.pdf

https://www.c3controls.com/blog/unde...g-trip-curves/

Bob Roach

I am glad I came across this article. A breaker between the battery and the winch is a very good idea.

When I did a clean up on my Police Package Cherokee wiring several years ago I put a breaker between the battery and the Fuse Box I installed to power all of the emergency equipment. This allowed me to kill the power to all of the equipment that would run the battery down when the vehicle was not used for a few days at a time.

I like the idea of being able to kill the power to the winch easily, along with the protection of a breaker.

Bob R

TxCoastie

Props to the OP! I feel much more at ease after install. Power on the line side only until the winch needed.

Mr.T

Thanks for the kind words! Mine now has the red Odyssey battery as well, great power and they seem to last a long time.

Bob Roach

So far I have not put a winch on my Jeep. However I did install one on my Polaris Ranger UTV. I put the circuit breaker under the hood where it would not get covered in mud. I also installed a 50" light bar front, a small light bar rear and Blue LED's under the dash to illuminate the floor. I then let my local electronic shop wire all the controls and switches up to only work with the key on. I am totally happy with the install.
Thanks again for reminding me about using a circuit breaker.

Bob R