I'm new to electical stuff and I was given this beast. What would be a good project?
Close-up.
>>998855
Wind generator.
>>998855
Make a giant tattoo gun with a piece of sharpened rebar
>>998855
Half HP, 1700 RPM. You could use it in a drill press, a lathe, a grinder, a polisher, a sanding station, a scroll saw, or a weak table saw.
>>998863
Wow. I didn't realize this thing would be able to do any of that. So I am assuming that it would he possible to use some sort of speed controller on this unit?
![693605284_tp[1].jpg](https://i.imgur.com/UaxNIzG.jpg "693605284_tp[1].jpg")
>>998865
Yup. They are called called a step pulleys. You put one on the motor and an inverse one on the other shaft you wish to rotate, When you want it to spin slow you put the belt on the smallest step of the pulley on the motor and the largest on the shaft. As you wish the speed to increase you move up the steps in the pulleys. This is how most multi-speed shop power tools operate.
>>998855
Fo both sides spin? If so, bench grinder.
![Delta_01[1].jpg~original.jpg](https://i.imgur.com/KlTVlLw.jpg "Delta_01[1].jpg~original.jpg")
>>998872
Pic related, a drill press with its belt guards removed.
>>998872
Okay! Yeah I have seen those in a drill press before.
Is there any way to tell if I could achieve something like that through a veriable switch like a a light switch dimmer for example?
>>998876
Nothing that simple, no. You have an AC motor and it would need "pulse width modulation" to limit its speed. Problem is, it would also limit its power. Its also not easy for a beginner to through together. If it was a DC motor, sure. Thats a common mod for old tools in fact. Get a hefty DC motor out of a treadmill and use the controller board to change the RPM. There are also special AC motors that have the feature. The Shopsmith tool uses one, for example. Its not something you can modify into a regular AC motor though.
>>998903
Well then. I will have to avoid that route. The step pulley system is not terrible, I will just have to learn some stuff. I sell pulleys and v-belts on a regular basis through work so Its something that would be good to know.
I will have to keep an eye out for a DC motor now.
Second question! Like I said I am new to this stuff. What us the optimal way to give this thing power. I have a picture of the wires. Should I have it setup to just plugin or wiring it into a box with a switch. Also.. there are four cables.. from what I know most extension cords are three. Who is the odd man out!
>>998903
Mate do you even triac?
>>998855
Let it sit until you have a need for it. Youll be thankful when it comes in handy.
>>998903
Ok I dont want to hijack this thread but can you talk a little more about how one would go about creating a speed controller for an ac motor?
Just got a few big motors and I want to be able to use them at any speed I want.
>>999031
That means it's a three phase motor. You probably aren't going to have three phase power in your house/wherever you are, so you'll need some way to convert from single phase to three phase. Easiest way to do that is with a VFD (which will also allow you to control the speed easily).
Something else I'd like to point out is the motor can be wired to run on 230V or 460V, as indicated on the wiring diagram in your second pic. It will not run on 115V. It's probably already wired for 230V, but before you do anything with it you should open up the cover plate on the thing and make sure the terminals on the board are wired for whatever voltage you're trying to run it at.
>>998855
1/2 horsepower three phase you lucky bastard.
perfect size and type for building your own sybian
>>998855
unless you have 3ph at your house its worthless
Well as this is a thread about electric motors: hello /diy/, I have access to an abandoned power plant and I found at least one working 75kw electric motor, this beast weighs 500kg. I only have access to single phase 230v and about 25 amps. What do?
>>999720
>motor weighs as much as this man
Jesus christ. Im not sure you can really do anything with it
>>999032
triacs don't work well on induction motors dingus. As you drop the speed you also drastically drop the voltage and subsequently heat up the windings in the stator. It also makes the motor weak as fuck at slower speeds.
Pulley: doesn't harm motor, less speed=moar powar, breaks once a millennia in a homegamer's shop machine
unless you want to buy a $$$ variable frequency drive, stick to pulleys.
>>999720
>75kw
>230v
>75000/230=326
requires ~326 amps to turn, assuming that the rating for power generated at speed is roughly equal to the power required to turn it under load . unless you can truck that bad boy to the top of a tower and put blades on it, probably nothing desu
>>999720
if nothing else scrap it for the copper
>>999740
At 75kW, it is almost certainly a 480V, 3-phase motor.
He won't even have the right KIND of service to run it. Nevermind the fact that his entire residential connection wouldn't be able to bring it up to rated power even if he bought a VFD large enough to handle such a load.
I can't even imagine what you'd do with it in a house. That's an order of magnitude above even the most powerful shop tools you could realistically expect to find in a home.
I mean, fuck, I have very good rates for electric and it would STILL cost me nearly $15/hour to run.
>>999720
search for other motors and undercut their prices.
>>999720
Buy property on a river, set it up with a turbine as a generator, and have free electricity for life.
>>999784
The motor is rated for voltages between 480 and 690 volts if I remember correctly, there's a crane in the machine hall where the motor is located however I really have no way of getting it out of the building. Anyway I have been thinking about ways to make a circuit that would would limit current so that I could hook up the motor and run it on really low power (just because it's cool) without instantly blowing the fuse
>>999898
Is there still power to the building?
>>999948
Yes, as I said, 230v in total 25 amps, or with some rewiring, closer to 50 amps
Couldn't find any other electrical thread so I thought I'd ask my question in here instead of starting one.
How hard would it be to install a ceiling fan and hook it up to a lightswitch?
As of right now the switch activates an outlet along the wall, I guess I'd have to mess with the circuits in order to make the outlet always stay on and direct the switch to the new ceiling fan.
Any advice /diy/?
30 posts in and no one has used the word "sybian" yet. I'm disappointed.
>>1000511
Hire an electrician man.
There's a reason they go to school for it.
You run the chance of fucking up the room, the house, and/or your life.
>>999514
see above >>1000516
got something like this second hand 8 years ago. self propelled, but that failed 3 years ago. I just removed the guts and push it around myself. 6.5 briggs and stratton from around 1995. Smokes a bit on start up and requires 2 pulls to start, but runs like a champ. All I've ever done is change the oil and spark plug once a year. Love the casters.
>>1000526
>got something like this second hand 8 years ago. self propelled, but that failed 3 years ago. I just removed the guts and push it around myself. 6.5 briggs and stratton from around 1995. Smokes a bit on start up and requires 2 pulls to start, but runs like a champ. All I've ever done is change the oil and spark plug once a year. Love the casters.
wrong thread
>>1000522
Missed that, thanks.
>>999950
lol
start a small foundry with free electricity. run it 24/7 for no reason.
>>1001749
Well there's the problem, I don't have that.
However, would it be possible to use electric ballast to limit current flow and run it on much lower current? Just to confirm it does really work, at least it seems to be in very good shape (the shaft rotates with very little friction)
>>1001798
bloke, its a 3 phase motor.
you know the type motor that requires 3 phases to induce a current in the rotor which creates it's own magnetic field which interacts with the rotating magnetic field that exists in the stator (due to 3 phase power) and creates torque.
This means you cannot (CANNOT) run ANY 3 phase motor on a single phase supply without some serious electrical wizardry.
If the motor is 400/690 volt machine it is a 400VAC in DELTA configuration and 690VAC STAR.
if you had the slightest chance of getting this thing going get the biggest 1-3 phase VSD set the ramp up time high and connect the motor in STAR (690V windings, less inrush current due to relatively high resistive component of motor load) and make sure no load is coupled to motor and you may need to hand start the motor shaft. The VSD will apply up to 230VAC 3 phase to the motor.
These dumb cunts telling you you cant run the thing because it'll pull 100A per phase haven't taken into account the motor has NO LOAD on it.
Now they'll jump up and down and attempt to educate me on startup current. Thats why we are applying 230VAC line to a motor in 690VAC line configuration. Motor current, whether starting or or running will be 3 times less than at rated.
Considering the motor is on no load and using a VSD to control the motor it may be possible to run the motor but single to three phase VSD's only seem to go to 10kW so really clutching straws.
Now that's all assuming this motor is a squirrel cage induction motor.
>>1002274
Ahem, actually you can run a 3 phase motor on single phase electricity (sure seems like wizardry tho)
You just manually spin the rotor and then turn on the power and somehow it magically works. Don't ask me how, but you can google it.
>>1002274
How can I make an electronic motor speed controller for a big 3ph 5hp squirrel cage induction motor. Ideally have it hooked up to a twist grip throttle.
>>1002520
Ahem, actually if you read the thread you'll find that we're talking about a 75kW motor. As soon as you apply 1 phase power to the motor in any configuration the circuit breaker will operate.
I'll agree with you that when you apply 1 phase to a (smaller say less than 2-3kW) 3 phase motor and spin the shaft the motor will run at severely reduced torque, will hum quite loudly and pole/cog and generally be quite useless.
>>1002535
I don't know. To enable a squirrel cage motor to change its running speed you must change the frequency of the supply. You cannot use a simple leading/trailing edge control on the ac waveform as that will simply reduce motor voltage/current and not vary the speed.
To have anything that's actually useful and does the job efficiently and effectively I'd be just buying a VSD and then all you have to do is marry your twist grip to a pot and connect that to the VSD and program it accordingly.
To make an electromechanical speed controller, get a DC motor, couple it to a AC generator and your done but the VSD will be significantly cheaper and allow greater control.
just put spindles on it and a stand and you have a buffer motor
>>1002710
Who you just replied to is me, the guy who actually has the motor, and while you are right in that if the motor was hooked up directly to the mains, the breaker would go off. However, if I were to put some kind of current limitingdevice on the circuit, it would be able to run on single phase as I was trying to say. Anyway thanks for your reply. The question now is: can I use electric ballast to limit the current to the motor?
>>1000511
Does the fan have pull switches? I installed one yesterday, it said to attach both wires of the light and motor of the fan to the hot of the switch, just turn the power off, check it with a tester then check out what you got. Refer to the included manual. Itll help.
>>1002899
The problem is a 3 phase motor by design cannot work off 1 phase power. The only way to get even close to having the motor useful on 1 phase supply is use a run capacitor in series with one leg of the motor windings. This will create a current flow in the other winding up to 90 degrees out of phase with the current flowing in the winding directly connected to supply which will create a rotating magnetic field in the stator which will induce a current in the rotor, and so on. Having said that the motor will develop less torque and be less efficient/effective.
A current limiting ballast will not be required as the current flowing in the winding when the rotor is spinning is inversely proportional to the rotor speed. Motor losses (apart from friction) remain relatively constant (apart from rotor losses, which is generally designed to be optimized when running at rated speed) so as the rotor accelerates (under no load) stator current decreases.
To do this if your motor is a six wire motor i'd configure it in star. connect neural to the star point, connect supply to 1 motor phase wire and connect 1 side of the capacitor to supply and the other terminal to another motor phase wire and leave the remainder disconnected and please have a circuit breaker protecting the wires your using and good luck.
>>1003168 thanks for your input, but wouldn't it still be a good idea to have electric ballast as protection in the circuit? I mean the inrush current from the motor would probably very easily exceed 25 amps still. And the thing is, this place doesn't have a modern circuit breaker, it has fuses, and I don't wanna have to replace them a lot. Also I have acces to some old electric ballast I also found there. Pic: some of the motors I've found, they are in much better condition than it seems.
do a fan with it
>>1003522
Not really, in the industry a magnetic ballast has never been used in motor starting applications apart from saturable core reactor which is very specialty and rarely found.
Inrush current as a result of DOL motor starting is generally ignored in circuit protection as the circuit protection device is designed to protect the cable not any perspective appliance to be connected whether it be a motor or not.
In addition to that motor DOL starting current is generally no where near instant trip level for a given circuit breaker even though the current flowing can be above its rated trip value.
Remember I squared t!!!!!!!!!!!!!!!!! I2t
Can we clarify which motor we are talking about now? the little dual shaft motor in op's pic or are we talking the 75kw one to be stolen?
>>999082
You can do it cheap or you can do it gud.
http://www.ebay.com/itm/201279252593
http://www.ebay.com/itm/181513986383
why is there a dead body in the pic?
>>1003522
If you have both fuses and circut breakers in a circuit any load able to blow the fuse will usually blow it before the circuit breaker even wakes up to kick in. Fuses can blow in less than one cycle.
Look at the time current curves. He can install a circuit breaker in his device and still likely blow his fuses because the fuse is probably several times faster than the breaker.
>>1003564
As if there is anything wrong with having dead bodies laying about.
>>1003563
They are 5HP motors, squirrel cage induction. Fat nasty encoder on the back that I don't even know how to fuck around with.
I want to try to use 'em for an electric vehicle. Seems to me like I need these things: A suitably rated AC drive kind of like you posted, a programmed microcontroller, and some kind of control system for me attached to the microcontroller (ideally twist grip throttle). I also am going to obviously need a lot of batteries and a good voltage regulator.
Here is where I'm at: I have the motors, I have access to microcontrollers and the software to program them, I can get/borrow some ac motor drives. I have no batteries, and honestly I do not have as much electrical experience as I would like. But I do have money, and that's a pretty good place to start.
>>1003584
This will be very costly.
You will need a suitably sized inverter for the batteries to supply either 1 phase or 3 phase power. Then a suitably sized VSD for the motor either 1 phase or 3 phase in, both the inverter and the VSD probably wants to be the next size up to handle sustained acceleration under load as generally these things are designed for relatively stable speed/loading conditions.
Your twist grip accelerator is quite simply, as i mentioned previously all you have to do is join the twist grip to a potentiometer as most VSD's have analogue input for a potentiometer.
Please note a small technicality if you set it up this way the twist grip wont "throttle" as such. The pots position is the desired motor RPM. That means that acceleration rate will be constant as set by the ramp time in the programming. The motor will accelerate at constant rate to newly set pot position.
you could also set up the VSD to electronically brake the motor when the pot is below actual shaft speed. This may not be desirable because you cannot coast.
You may need a complex VSD and control to have the VSD both coast and brake and the brake rate would again be constant unlike a hydraulic brake in a car which is variable depending on pedal pressure.
Do you have to use batteries or can you use mains or a portable generator? batteries really make it hard.
You should see if you can track down a VSD that doesn't utilise the AC input at all apart from the rectifier, that way you could have a high voltage battery pack directly feeding into the VSD's DC supply rail (via a inductor). approx. 350VDC for a 1 phase unit and approx 600VDC for a 3 phase unit.
That will enable you not to require an inverter.
>>998861
For elephants, I presume.
