new motor controller

[nileshc]

I have used the same motor controller over a year and now the controller has caught on fire twice and now I really need a reliable motor controller. Here's a link to the controller that has caught on fire.
http://tncscooters.com/index.php?route=product/product&path=41_74&product_id=182

I have 3 batteries that are 12 volt and 18ah each to a total of 36 volts.

 

[landuse]

I have used the same motor controller over a year and now the controller has caught on fire twice and now I really need a reliable motor controller. Here's a link to the controller that has caught on fire. route=product/product&path=41_74&product_id=182"]http://tncscooters.com/index.php?route=product/product&path=41_74&product_id=182[/URL]
I have 3 batteries that are 12 volt and 18ah each to a total of 36 volts.

Link isn't working

Edit: Never mind. I fixed it

 

[itsid]

it's not about the batteries it's about the motor..
I tryed to find out reading your previous posts... but without success.

So what motor do you have;
and pleaaaase don't tell me 3000rpm.. that's an information as useless as it's outer diameter.

to calculate what controller you need, we need to know it's electrical power.
If you cannot find out, then please measure it's inner resistance.
but do not round, quote your multimeter precisely!

If it's indeed the 3HP you mentioned once...
then that's the problem

3hp are 2238 Watt for a 36V system that means a power draw of 62.2Amps;
your controller can provide up to 40 Amps
the motor tries to draw 150%... and the mosfets heat up dramatically

and a hp rating almost always means mechanical power... so it'll not only draw 62.2Amps but more something like 77-82Amps...

'sid

 

[nileshc]

It's a 1000 watt motor. It draws 35.6 amps.

 

[dcastillo]

question, when you say its caught on fire twice... what exactly caught on fire? the physical controller itself, or the cable harness next to it? Im confused how the controller would catch fire and still work....

Also, at full throttle, if the wheels are locked, it could draw more than that.

-Danny

 

[itsid]

ODD...

would you mind to open up the controller and post a pic to see what caused the failure?

Anyways, the controllers all use roughly the same schematics and parts,
so if two CT controllers fail.. most likely the YK will too!

I suspect some other major issue here, it's either a bad motor
i.e. bad efficiency rating below 70% and drawing above 40Amps in reality.
a bad gear ratio /wheel combo
i.e. the motor is under constant load and building up too much heat which then decreases efficiency
or bad electrical wiring
i.e. you have a current leak or even a short somewhere.

Many things can be wrong I only named a few.
So I'm afraid.

I'm sorry, but it's basically simple;
the controller is a passive unit;
as long as you do not try to draw too much currents
(or it's rated current over a too long period of time)
it should not fail... one can every now and then,
it's still a cheap chinese part...
but two in a row? very unlikely (although still possible of course)

Now any third controller in that price range is as good as the one you had;
any more expensive controller will also burn and fail if it's -as I suspect- not the controllers fault.

Okay, since you asked... the JLStar Ultipower motor controller is stable up to 50A,
(for the 1000W model) but it's indeed expensive (~150€ or $200 US)
http://shop.mat-con.net/jlstar1kw36v (sorry, only have a german shop for that one ATM)

the same 50A rating (continuous 30A)
can be had with a kelly for a much nicer price
http://kellycontroller.com/kds36050e50a24v-36v-p-138.html
or one step up with 60A continuous
http://kellycontroller.com/kds48100e100a24v-48v-p-285.html

both need a slightly different wiring than what you got now.

But again... make sure the issue is/was indeed the controller, it may be just a victim

'sid

 

[nileshc]

I think it's my gearing, I have 12 tooth on my motor and 45 in my axle

 

[dcastillo]

(I got this one Sid )

we are going to need to know your tire size size as well big difference if your running 10" tires or 16"

(but its safe to say thats not a good ratio.... most people do a 1/7 or so... you really need a bigger axle sprocket and/or smaller motor sprocket)

 

[dcastillo]

BTW, my first cart was a 12t on the motor and a 70t on the wheel...

 

[nileshc]

10 inch wheels
Should I go for 60 teeth on the axle or something different

 

[dcastillo]

your current gear ratio is 3.75...

a 70t sprocket would get you close to 6... thats what I would go for....

BTW, how was the acceleration on you cart... with a 3.75 ratio I can imagine it was that good....

 

[nileshc]

Acceleration wasn't good, it was the speed that I was looking for, but I was only getting 20

 

[dcastillo]

sounds like you need a more powerful motor

you might be better with the 60 tooth then... you should still hit close to 15, but with better acceleration

 

[nileshc]

So is there a motor that is isn't costly that I could get that's less than $200

Would this also mean upgrading my motor controller and new batteries?

 

[dcastillo]

correct...
not sure about finding a motor... I have a 2000W golfcart motor from 1982 that I got for free on craigslist
most of the motors over 2Hp start to get pricey if bought new...
if your handy, you could get a 24V start from a large truck (at the junk yard) and use that, those can easily be a few HP, but may not last as long.

some will say its a bad idea (some wont) but you could get a 48V controller (at higher current) and over volt your motor as well.... keep in mind it is a little more dangerous and could shorten the life of the motor as well...

-Danny

 

[nileshc]

Can you send me a link for the motor on Craiglists

 

[dcastillo]

as others would say, fill out your location in your profile so we know where your at

Craigslist is a local thing, you would need to search it for your hometown....

 

[itsid]

(I got this one Sid )

Thanks.. he's all yours

read about his ratio and -what should I say- I'm glad you took care of that already

'sid