A Few Electrical Questions
 

I am currently working on a robot style project using the 2001 control system. I have it all worked out, but I lacking a few vital elements....any help you may offer me is greatly apprichated.

Where Can I locate the 120A on/off switch? I looked on FIRST for the supplier of that, it doesnt have to be like the ones we use for FIRST, any 120A switch will work.

Where can I purchase the "spinning lights" we use for first, I took a look online and on the FIRST homepage with no luck.

Thanks,

-Greg The Great

The 120A main breakers that FIRST supplied us with can usually be found at Marine Surplus Stores.

Blue Sea Systems makes something very very much like what we used, if they didn't supply them exactly. The model 7113 seems to be their 120A breaker, but they're available in ratings from 25A to 150A, in that same style.

http://www.bluesea.com/Products/CB/CB.htm
http://www.bluesea.com/catalog_.pdf/...ussmann_cb.pdf

I'm willing to bet that you could walk into almost any automotive or marine supply store, and ask if they have any high-amperage circuit breakers, and they'd be more than willing to help you out. I'm not too sure about pricing. You might have to pay $50 for a good one, but that's just a guess.

If you have a Lowes nearby (I know most of Indiana does) they have the Square-D breakers used in 2001 well beyond 120 amps in stock.

On the rotating light...well im not sure. I know the company was based near Chicago. Sorry I cant be any more help.

-D.J.

Greg,
MCM Electronics is a great place to get stuff including the circuit breaker. Check at www.mcminone.com and they have a 100Amp and a 140 Amp Part # 60-3760 and 60-3765 respectively at $19.60 single unit price. The light this year came from Japan but in previous years was from North American Signal http://www.nasig.com/ in my hometown. The lights supplied by FIRST drew about 4 amps, this year's light was a lot lower primarily due to a tiny motor for rotaing the reflector.

would you recomend he 100 or 140 coming of the positive lead of a FIRST 12 volt DC battery (exide)?

-Greg The Great

I know no one asked my opinion....
But:

Do you plan on needing the extra 40 amps anyway? what are you planning? is it a high current application?

I am looking to run 3 or 4 FP's, 2 Drills, 3 selanoids, and 2 Johnsons, and a 12 volt DC light.

-Greg The Great

Hmm....while the 100amp would probably work if you get any heavy load on the drills you run the risk of tripping it, the 140 would probably be better, can anybody else chime in here?

Btw, make sure you get connector rated for the current, the Andersons welded themselves when running too high, only rated for 60amps.

getting connectors rated for the right current is pretty important. i herd from a few people that the anderson conectors tended to overheat due to over current and melt the insulation (not weld themselves together) but never actually saw that happen.

and id probly recommend a 140 amp main breaker jus to be safe

Didnt they have 60 amp breakers in the past year, this year being the first with a 120 amp?

As for the lights, my team my have an extra one laying around, I will ask the teacher.

Are you going to be stalling the motors? If not, the 60 amps is all you need. I definetly wouldn't go with 140, unless you size your wires and connectors accordingly.

The red Anderson Power connectors that we have used in the past are only rated for 50 amps. Unless you really know what you are doing, your circuit breaker should be smaller then the current rating of your connectors.

People always complain about tripping the circuit breaker, but that's a whole lot better then melting wires, connectors, or fingers.

Thanks for asking, the only one I could find is like 70 bucks and I am already in this project to heavy, and a breaker will set me back some more.

Thanks for the help all, I will probabally go with a 60 or 80 breaker followed by a switch (light switch).

Does ne1 see a problem with this...

-Greg The Great

Greg,
The 100 amp is fine. Remember the breaker is there to protect the battery from high current loads. Be sure to use the wiring specifications for size as listed in the robot manual and you should be fine. If you are going to use smaller wire, then you may need to go to a smaller circuit breaker.
The 60 amp breaker used in previous years was specially designed and rated for 48 volt DC operation so any old 60 amp breaker would not function the same.
The Anderson connectors work OK if they are propoerly terminated and are not damaged when inserted into the plastic block. A misaligned terminal causes a high resistance connection. High resistance and high current result in heating of the contacts and early failure. I just listed MCM as a source because I saw the connectors while paging through the catalog.

Thanks. I guess that sums it up, Thanks all.

-Greg The Great

Northern Tool has a rotating light very similar to the one in the kit but the lense is yellow.