electrical problems

[dieselpower]

im sorry if i shouldn't be posting this here, but people have a lot more knowledge then i have and figure someone can help.
this isn't directly vehical related, but i just aquired a wheel balancer to be used on my cars. anyway i live in a small rural area and can't get the 3 phase power that i need to run it. and a phase converter costs more then what the balancer is worth to me. anyway i already have another 3 phase motor and moderate electrical knowledge. i figure i could build a static phase converter but i've read that on delta-wound, witch is what the motor is,you only get about half the horspower. so my idea is to build a static phase controler to get my extra motor spinning, then running 220 single phase to two of the posts and then taking the extra post for the 3rd phase to run the balancer. will this actually work and do u see any problems with it?

thanks for the help..

Mark

[QuickTD]

I'm an electronics tech of sorts in real life so I'll try to offer some assistance. First of all, why not just change the motor? I doubt that it is more than a fractional HP unit. The internal electronics, even on quite sophisticated machinery, are usually run from a single phase of the incoming lines so that portion of the machine shouldn't be an issue.

 If the motor is an integral part of the unit, another method of side stepping the problem is to use an electronic inverter drive. Smaller units (<1hp) are available for a couple of hundred bucks these days. Then you just run single phase into the inverter and get 3 phase out. The inverter controls can be wired to the start/stop relay presently in the balancer to start and stop the drive as needed.

 I'm not a proponent of rotary phase converters, they are noisy, inefficient and produce poor quality power. I would go to great lengths to avoid thier use...

[dieselpower]

thanks for the advice.
the motor could be changed but it looks pretty integrated into the machine and would be more work to change then to buy an inverter. my dad said he thinks it 3 hp. the thing is i doubt it takes 3 hp to get a 15inch wheel spinning. so would the inverter drive still work and will i loose power by using it?

also i read that if you use a jumper motor to get a 3 phase motor spinning, you can run it off single phase using 2 of the 3 posts. r you familiar with this? and would just spinning the wheel before the button is pressed to engage the motor be enough to get it to work.

i have access to wheel balancers and can use them for free, so it's not really worth 300bucks to keep this one. it would just be convenient if i could operate it cheaply.

thanks for the help

Mark

[QuickTD]

the thing is i doubt it takes 3 hp to get a 15inch wheel spinning. so would the inverter drive still work and will i loose power by using it?

I would be pretty surprised if it was 3hp, seems like alot just to spin the unloaded wheel. You could still use an inverter but they tend to not be offered (cheaply, at least) in single phase input at power levels beyond fractional. An invertor will not cost you any running power. It will very likely accelerate the motor a bit slower because the inverter cannot supply very high starting current like the line can...  

also i read that if you use a jumper motor to get a 3 phase motor spinning, you can run it off single phase using 2 of the 3 posts. r you familiar with this? and would just spinning the wheel before the button is pressed to engage the motor be enough to get it to work.

This is actually the principle of the rotary phase converter. All squirrel cage electric motors are technically three phase. A single phase motor just incorporates a phase shifting network (capacitors or a seperate "start" winding) to shift one leg of the incoming line to approximate 3 phase. Once the motor is spinning the phase shifting network is then switched off by a centrifugal mechanism. Some heavy duty motors may also use "run" capacitors to improve torque when running.

 I've seen people wind a rope around a pulley on the end of a three phase motor and pull it like a recoil starter, once the motor is spinning they switch the single phase power on to two legs of the motor and away it goes. Once running the third phase can be pulled from the remaining leg of the motor. Quick and very dirty rotary phase converter. I'm not sure this technique would be reliable enough for day-to-day use...