Anchor windlass circuit breaker sizing

Have spoken to maxwell
They are OK with me using another brand of breaker but recommend 135 amp so as not to overload and damage the motor as suggested here already.

Interesting using google images and looking at various breakers.


All look suspiciously similar to me , same breaker in different housing and are all around the $150 mark.

This one looks similar as well, especially to the maxwell , same text even?
It is 135 amp and is rated for marine usage
It only costs $44

Sounds like a winner

 

Thats the next on the list.
Once again, Maxwell solenoids are in a box

Others are more exposed


and with a marine name on them, they all cost between $150 and $200

And one without the big Marine type name on it costs $25


I imagine the latter will do the same job as the others?

 

I eat thru Cole Hersee relays. I dont know the others.

Again...I prefer relays that allow me to visually inspect the contactors.

I like the Albright series. If they are availble in your region have a look to see if they are price competitive. .

http://www.albrightinternational.com/files/downloads/catalogues/SW180 LEAFLET.pdf

 

For circuit protection Ive been simply using knife fuses. Cheap.

 

The windlass maker also supplies the relay, but he may call it "control box". At least that is what Lofrans does. It contains 2 relays with the proper rating, cross connected for fwd/reverse operation. There are 3 terminals for a control switch, drawing less than 1 Amp.

 

RX, the electrical resistance of copper and virtually everything else increases with temperature. The relationship is not linear, though, and in copper, the coef decreases with increasing temp from room temp on up. This confuses many people. The inductance of magnets and other devises are also affected by temperature in their own way and they will significantly alter the cookbook answer. No simple breaker derating table should be used to adjust the load physics. If the breaker has its own internal quirks, so be it. The maximum nondestructive overcurrent is often temp dependant.

http://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity

That business about derating CB's should be handled by MFG and incorporated in the docs they supply if necessary. I think it will do more harm than good if everyone starts fiddling with breaker ratings- what if the installer already got it right? It is a very case specific issue. Keep it out of the field, let the MFGs handle it.

 

Thanks for that
any suggestion as to which one for my requirements?

And they do have a reseller in Oz, about 30 klm away from me
http://www.bridex.com.au/albright.htm

I suppose I can give them a call, but recommendations from an actual user would be helpful to someone (me) who is clueless to all things electrical.

 

Is the installer familiar with the operators technique. is he aware of the weight of chain and anchor.

I understand ampage and current draw and how to haul,-- I am the breaker.


But you could use a breaker if you dont know how to use the equipment without blowing it. Or even to give you confidence that your boat is the same as everyone elses even though you may not be sure what it is for.

Dragging now--only 6 feet off the harbour wall , damn that squall is getting stronger. I wish I had some one on board could hold the boat into the wind and unload this windlas. Damn that breaker.

 

Philsweet,

The explanation I gave was for the general idea how things work and not the mathematics of the whole thing. If I were to to use Wiki's material, i would rather use my Electronic Design manual.

I was being myopic when I said "copper wire". I should have said "copper winding" if that confuses you.

Like the circuit breakers, it is a general derating curve as published, meant to guide users who do not need to take up math. Breaker manufacturers do not publish their derating curves anyway and Maxwell published data itself did not explain why the current consumption of 110 ampere to 135 amperes when the math tells us a 1,200 watt motor would require only 100 amperes @ 12volts. The OP only wanted to choose between 100 amp and 150 amp circuit breaker.

 

RX, you didn't confuse me, I'm disagreeing with everything you said in that post. Mostly I'm worried that the way in which the post reads will provide the average boat owner with some supporting rational in thinking that installing a bigger breaker might be a good idea. I was hoping you would either retract it or delete it. The first fact is wrong, the chain of logic that follows is wrong/ backwards, and then you dragged a table into it that has no application either to the original post or to your example and only applies to a specific sort of breaker device. It would not apply to any boater in Florida. It might be something that would need to be looked at on a pump panel in a boiler room. Then you have a powwow with the pump guy and electrician and make sure everyone is on the same page. It is not something you do lightly because of the risk of it getting applied twice. The last thing that is needed is for the average boat owner to have some pseudo-rational supporting his want to try a bigger breaker in a circuit. My concern is mostly about the flagrant misuse of what you wrote by others than nitpicking the details of it. Sorry for the strong reply, maybe I'm overreacting, but I believe this is potentially quite dangerous.

Do not derate breakers. This is not within the perview of field tech. It can only be safely done when the entire scope of the code compliance is understood. There are usually better alternatives. It is basically admitting that you are using something outside its intended range of operation, such as in a smoking hot pump panel beside a boiler flue. There is a reason manufactures don't publish this stuff.

As for wiki, it is as silly to dismiss it out of hand as it is to believe it at face value. I wasn't suggesting it as a design manual. But it is reasonable support in a forum discussion, I think. The wiki is sourced, your derating table is not.

 

They work. Ive been using them for 20 years. Lewmar uses them on hydraulic powerpacks.

Another worthwhile addition to your winch installation is a chain counter. Many different brands, but they all work the same...a magnet is buried into the gypsy and a sensor counts each gypsy revolution. very precise and it allows you to single handily retrieve the anchor, at night, in a howling gale, to within a gypsy diameter of the stem head anchor roller. I use it every day.

 

Phil,

Electronics Engineering is my first discipline and I know what I am talking about. My intention was to provide as much information from what i can gather.

Here. From Reference Data for Radio Engineers- Howard Sams & Co., Electronic Engineers Handbook- Fink Christiansen, and West Marine Catalogue.

 

Follow the manufacturers instructions, but oversize your wiring to compensate for I squared R losses (resistance and heat build up in the conductor)(fire hazard) which in turn lowers your supply voltage to your motor and causes it to heat up, (more I squared R losses overheating and motor burn out)( fire hazard) By simply oversizing your wiring you are: #1 reducing the possibility of ever tripping the 135amp. circuit breaker, #2 Reducing the possibility of overheating and burning out the motor and prolonging it's life by up to 100% or more. #3 Surpassing the manufactures specs. and reducing any conflict over warranty and #4 greatly reducing any fire hazard. Most important inspect and keep all connections clean and tight.( corrosion resistance at a connector can also be a hazard)-- Geo. CET(electrical/electronics)

A yacht is not defined by the vessel but by the care and love of her owner--

 

Thank you RX, From the Blue Sea info - "The effect of temperature on current carrying ability is as follows"- (and a table like yours). Nothing about derating which is an entirely different thing. The table shows the performance characteristics. They are designed in intentionally. They are not an inconvenience that one must deal with. The ampacity of the field wiring decreases with increasing temp and the breaker is designed to track the performance of the wiring if all is done to standard. If you derate the breaker it won't nuisance trip but the wires may melt. It provides robustness. My concern was that a boat owner might have regarded it as a lack of robustness based on your wording. Installed machinery which has particular problems with heat will have its own safety devices. My experience down in the Keys is with folks who found a $25 windless in a fleamarket, screwed it to the deck, and hooked it up to the running-light circuit . After a few fuses, they came and got me. Some are friends and I worry about them. They are the ones who will find this thread from a google search and may think they can derate the breaker because they live in Florida. I Guess I've done all the flag waving and foot stomping I can. As I said before, it was the potential misuse of the data you posted that concerned me the most..

 

Phil,

You're welcome. The derating chart as given by Blue Sea system, that is, you lose about 10% of current carrying capacity of the c.b. if your ambient temperature rises from 75F (23C) to 100 (37C, very uncomfortable), Really not much as it will be a very bad design if the c.b. is in a 200 degree environment. At that temp even the battery fluid will start to boil when it starts discharging.

The most important is the correct wire size (Post no. 8) also noted by other members. It is easy to lose 10% of the voltage by choosing the wrong wire or a run too long as elaborated by Viking North. Note also that the breaker must be near the source. Cut off the source and you cut off the source of fire, unless of course the fire has already started.