Electric Kart Help

[SBindra]

Hi
Im helping build an electric kart for my shop class. Im working on throttling the 24 volt DC motor. The motor is from an electric pallet jack.
This is the specification plate on the motor.http://i1228.photobucket.com/albums/ee458/sbindra/IMG_1825.jpg
This is the old wiring.http://i1228.photobucket.com/albums/ee458/sbindra/IMG_1826.jpg
I have no idea how any of the wiring used to connect to the motor. I can get better pictures if needed. If you can help me in anyway or point me in the right direction I would really appreciate it. Thanks!

 

[itsid]

Welcome.

Wow, that's a manly relay

Do you know the make and model of the pallet jack?
Then the best thing to do is find the service manual and get straight to the original wiring diagram.

From what I see on the pictures there are some cables ripped, I cannot trace them; but I'm pretty sure they're not meant that way

I think I have a basic idea what things are and where they belong, but playing with 100Amps isn't funny, all those open terminals; I do not want to guess and have anyone badly harmed, because of my mistake.

So let us know the make and model and find the manual to see for sure.

'sid

 

[Oxymoron]

Most of that wiring is for the other portions of the circuit, and not the motor (transformer, power supply, charging circuit, etc.). You only need to be concerned with the + and - from your controller to the motor.

I can't zoom in on the image of the motor to see if it has anything else to be concerned with (a physical brake for example)... but bottom line is that as long as you have a controller to handle the amperage, it should be pretty straight forward.

Sent from my Galaxy Nexus using Tapatalk 4

 

[itsid]

what do you mean by "most" ??

Allthough I am -again- not 100% sure about what goes where, I see no charging circuit at all atm.
The contactors (three silver cans) are most likely be part of a forward/reverse circuit,
the *grunt*relay is without a doubt part of the on/off switch, and what's needed to complete a full motor controller is a heavy duty poti for speed controll (may or may not be the grey box *shrugs*)
and a switching circuit for the can-connectors (might be the relay hanging from the table)

So if I'm wrong about the two boxes (the grey one and the one hanging from the table)
that'd be all there's left to be -maybe- part of a charging circuit.

*shrugs*

'sid

 

[SBindra]

I dont know the model of the pallet jack. As far as i know the motor doesnt have anything special on it but i can post a pic later. I can buy a controller if needed or if anyone has any diagrams of ones that will work. I know how to solder.
Thanks!

 

[Oxymoron]

What I mean by "most" is that the only two connections needed to make that motor turn are the positive and negative to the armature.

The rest is not needed, unless you're operating a pallet jack.

For a kart, you just need...
-Power source (batteries)
-Controller
-Throttle input to controller
-Overcurrent protection
-Disconnect switch
-Motor


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[itsid]

Hm.. well, I beg to differ

Well I haven't seen the motor connections yet, but I assume there are three.
So all three contactors should be used (hey, if the original setup provides reverse.. why not use it)
And the relay must be used (well.. should) since it makes sure you can disconnect the motor from the batteries at will; noone likes a 2.7kW motor going all mad max on you;
you want that thing off when you need to (throttle stuck @ fullspeed for example)

So what you need is at least 2 connections for the batteries, 2(assumingly three) for the motor, at least SIX for the controller and so on and so forth.

Making the motor turn is not a problem, making the motor turn at a specific speed and shutting the turning motor off in an instant is what motor control is all about.

First thing I'd do:
check all the relays.
the big one of course, and the three contactor cans (control are the smaller terminals up front, load the bigger left and right)
just add new test lines, do not remove the original ones just yet.
use low currents to test.
If they are all in working condition, you should draw a makeshift wiring diagram.
Trace all lines and make notes.
etc.
If not it can be lesser expensive to buy a newer modern controller;
or even build one yourself.

Note down all mfg part numbers and specs if you still have readable stickers or such.
basically:
know your enemy

'sid

 

[Oxymoron]

I wouldn't use a relay as a disconnecting means, unless it's a secondary means. I meant one of these...
http://www.cloudelectric.com/category-s/12695.htm

Relay contacts can weld, and I'd use a manual disconnecting means in addition to the convenience relay.

$.02

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[itsid]

sure they can weld.. but that thing up there;
I'd say it would need at least 300Amps (that is if the contacts are properly aligned again )
And it's only 24Volts, so the gap must be extremely small to even produce a spark, and it has these huge contact surfaces...
No, that beast will not weld anytime soon.

The contactors on the other hand might weld easily if they're corrupted,
but it's more likely that the internal solenoid dies before they're worn enough to spark and weld, and for further protection they're encapsulated to prevent oxygen degenerating the contacts...
So possible for sure, but very unlikely if they still work the way intended (hence the test)
given their size I'd say they're rated @~200Amps btw.

Anyways, of course you want to have a manual heavy duty switch.
But in case of a fatal error, not as your every day on/off device.
And such thing should be as close to the bat pack as possible, and thus maybe out of reach for the passenger.

'sid

 

[Oxymoron]

Safety is paramount.

In my years as an industrial electrician/automation tech, I've seen contacts weld with less than 24v potential, especially on high amperage loads. Unless there are redundant safety measures, the machine will either destroy itself, injure someone, our both.

Agree to disagree. I'm done with my soapbox. Carry on

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[dcastillo]

Although I plan to add that nice albright estop button (thanx for the link, didnt they existed that high in current) but as a backup I have informed my wife, if anything goes wrong, just reach back and grab whatever thick wire she shes on the batteries and pull... everything is put together using quick disconnects...
My biggest concern is when my kids drive by them selves , how often do people end up with runaway full power motors? Is there something that typically causes it?
thanx
Danny

 

[SBindra]

Hi
Here is the motor

And in the wiring there is a gray box with a code on it.

i have searched the code but it doesn't come up with anything.

 

[dcastillo]

that looks like one crazy motor

 

[dcastillo]

i dont know a lot about different motors, but it looks like it could be a compound motor (pg 10 http://www.bradleysmotors.com/pdf/Technical Data/2nd Set/Terminal_Markings_and_Motor_Connections.pdf) "
just some thoughts
-D

 

[itsid]

Safety is paramount.
I fully agree!

In my years as an industrial electrician/automation tech, I've seen contacts weld with less than 24v potential, especially on high amperage loads. Unless there are redundant safety measures, the machine will either destroy itself, injure someone, our both.

Agree to disagree. I'm done with my soapbox. Carry on

Well,
yeah everything can happen,
but as far as I understand the original post,
that parts all came with the exact same pallet jack,
so I'd say it's fair to assume that a qualified engineer had put this peces together, choosen wisely what to use and what not to use;
that this parts in working order will run the motor not only safely but also consistently durable.

Yes, the motor is made in sept 1966 so the electronics are nowhere close to modern standards, very true.

But that doesn't mean they wont work as intended, does it?

SBindra,
I'm sorry haven't found any informations on the GE module yet either.
It looks like the IC4484 series was quite common, and B-modules come in a variety of ranges, but so far I've only found two different A-modules at all, both are nowhere near yours.

Since all IC4484 are controllers to trip a contactor,
my best guess is it's either a forward/backward controller (to trigger the setting for at least two of your contactors, or it's a thermal shutoff (then it should have a trimpot somewhere)
Honestly, without a datasheet I'm lost on this one too.

Maybe you can kindly ask at GE directly for help, not all of their informations is necessarily listed on the website of course,
so you might be able to not only find the datasheet of your ic4484 but also a complete datasheet of your motor.
(and maybe other GE parts that you might have there)
http://www.geindustrial.com/cwc/electrical_homepage.htm

All old school datasheets I've seen so far come with a nice example wiring diagram for that item, so that'd be a huge help.

'sid

 

[Oxymoron]

Well,
yeah everything can happen,
but as far as I understand the original post,
that parts all came with the exact same pallet jack,
so I'd say it's fair to assume that a qualified engineer had put this peces together, choosen wisely what to use and what not to use;
that this parts in working order will run the motor not only safely but also consistently durable.

I wouldn't make that assumption. You never know who's been maintaining/modifying the equipment since 1966. Originally, I'm sure it was fine. What parts have been replaced since then? Were they adequate? Were they installed properly? Was the correct gauge wire used? Is the insulation still intact? Now, of course a qualified person could check all of that, but most people asking questions about the electrical aspects of their project on a forum, are probably not qualified. If they were, they'd be answering questions instead. Since the OP is asking... it would seem more prudent to direct them to the simplest, safest path... which in this case would be to remove anything non-essential, and replace the existing wiring with new. That way, there is nothing to assume.

Yes, the motor is made in sept 1966 so the electronics are nowhere close to modern standards, very true.

But that doesn't mean they wont work as intended, does it?

It's an unknown variable at this point, IMHO. Why not eliminate the unknowns, and go with new wiring. It's just my opinion, but if it were going to be my kart, I wouldn't use any of the existing wiring.

Also Sid,
I hope you don't think I'm just trying to debate with you for the fun of it. Judging by the amount of posts you have, and the vast spectrum of topics you cover, I know you're intelligent... and you're very helpful on the forum. I just want to make sure the OP is safe (as do you, obviously). The sum of all the members here, and the abundant wealth of knowledge that is the product of those members, is what makes this forum great! I don't usually post that often though... just read

Anyhow... cheers to all! I have to get back to work now

p.s. your sig is hilarious (I don't normally see it, because I use my phone rather than a computer)

OP, absorb all of the info in this thread, and use your best judgement

 

[Oxymoron]

My biggest concern is when my kids drive by them selves , how often do people end up with runaway full power motors? Is there something that typically causes it?
thanx
Danny

I don't know how often this happens, but the important thing is to have a way to manually disconnect power in the event of a failure.

Think of it as a seatbelt in your car... you may never get into an automobile accident. Then a gain you may... there's no way of knowing that. But if you do, it's a good thing you have a habit of putting your seatbelt on before driving, eh? You may never need it, but when you do, it better already be there. Dig? I would mount the E-stop right next to the brake pedal... that way you never have to remove your hands from the wheel and compromise control of the vehicle during the disconnect procedure.

mods, sorry for the double post

 

[dcastillo]

Thanx for the great advice...
havent really been super concerned with the estop yet since she hasnt really driven by herself at all... but will get one soon....
interesting thought about putting it by the brake
never would have thought of that...
-Danny

 

[SBindra]

Hi
Would it make it easier to just buy a controller and connect it to the motor? Then i wouldn't have to find out how the wiring harness works. If so is there a special kind of controller i need?
Thanks!

 

[itsid]

I wouldn't make that assumption. You never know who's been maintaining/modifying the equipment since 1966. Originally, I'm sure it was fine. What parts have been replaced since then? Were they adequate? Were they installed properly? Was the correct gauge wire used? Is the insulation still intact? Now, of course a qualified person could check all of that, but most people asking questions about the electrical aspects of their project on a forum, are probably not qualified. If they were, they'd be answering questions instead. Since the OP is asking... it would seem more prudent to direct them to the simplest, safest path... which in this case would be to remove anything non-essential, and replace the existing wiring with new. That way, there is nothing to assume.

Good point!
I would check/change all the wiring as soon as I know/noted where everything was before.
but because heavy gauge wires don't come cheap I would do that after I made sure that the key components (all of them) are in working condition.
And as far as I'm concerned we're still in the "make notes" process

It's an unknown variable at this point, IMHO. Why not eliminate the unknowns, and go with new wiring. It's just my opinion, but if it were going to be my kart, I wouldn't use any of the existing wiring.

as said, because for now the old wires give a hint how this was set up, later it should be replaced; most if not all of it.
I am nowhere near a state of confident to say "attach the two car batteries on this side of the pile and the motor on that and go" because I think I know what goes where, but I'm not sure yet.
But a 9V battery to test... of course

Also Sid,
I hope you don't think I'm just trying to debate with you for the fun of it. Judging by the amount of posts you have, and the vast spectrum of topics you cover, I know you're intelligent... and you're very helpful on the forum. I just want to make sure the OP is safe (as do you, obviously).
The sum of all the members here, and the abundant wealth of knowledge that is the product of those members, is what makes this forum great! I don't usually post that often though... just read

I know you're not trying to just bother me
Honestly, I think it's good that we have a different opinion on how to do things here.

We both want OP to stay safe of course;
personally, if old stuff like that is repairable I like to repair it and see how well it does, before I go and buy new components.
So I try to figure out what is working and what is not;
those contactors for example are expensive, if one is broken it costs almost the same as a new controller (~30USD)
but if nothing is broken, why spend money?
Or another viable route: make sure it's okay and sell the parts at ebay, and use the profit for the new controller.
And on the way to find out, you learned how this was setup,
you'll never know when this knowledge comes in handy

If I understand you right, you wouldn't bother with that dusty pile of parts and just take the motor and attach a fresh controller.
Very fast and easy solution, but less fun and less to learn

Thank you for your compliments, I do my best to help if I can,
I'm here to learn new stuff and share the little things I already know
well.. just like all of us I think.

'sid