View Full Version : 3 phase

04-23-2001, 07:29 PM
how much does 3 phase cost to in stall plus
the inverter,per machine?

04-23-2001, 10:26 PM
<font face="Verdana, Arial" size="2">Originally posted by doug:
how much does 3 phase cost to in stall plus
the inverter,per machine?</font>

That's kind of like asking how much a car costs.

I'm no expert but expect that you'll need to supply info like the HP for the motor on each machine for the inverters, how much total power you'll need for the 3-phase wiring, how you'll be distributing it to the various machines, what sort of environment (explosion proof electricals needed), etc.

With that sort of info added, maybe someone here more knowledgeable than I can supply you with some advice.

charlie coghill
04-24-2001, 11:49 PM
If you are talking about getting true 3 phase installed,it will depend on how close the nearest 3 phase line is to where you want to connect. You probley will not like the price.

If you just want to run a 3phase motor, a static starter will run about $150 and up depending on the size of the motor you want to run. These are/were limited to the times per minute you could start the motor. Another way that could be done and is the way I do it is use a static starter to start an other 3phase idler motor that is about 150% larger than the largest 3 phase motor you will want to run. This way after to idler motor is running the machine can be started as many and as often as you want.

Match the starter to you idler motor. 3phase motors are cheaper than single phase motors.

04-25-2001, 11:26 AM
The cost of getting 3-phase power installed is most likely "a whole lot more than you're willing to pay."

It is almost certainly MUCH more practical to either swap the motor for a single phase motor ($100 or so, maybe?) or, if that's impractical because of the motor design, get a phase converter. ($150-$500.)

Take a look at getting a surplus AC inverter drive. New they are outrageously expensive ($600+), but you can get surplus ones for a couple hundred bucks, and they are GREAT. In addition to giving good 3-phase power, they give you variable frequency speed control. I got one a couple of months ago and love it.

See, for example, http://www.vfds.com/ or http://www.dealerselectric.com/.

05-17-2001, 12:20 AM
Just to run it to your place,it will start at $5000 + $100-$200 minium month charge or a high peak charge, say $20 or so for each peak. HAY...but then you won't have to make a $100 phaser.

<font face="Verdana, Arial" size="2">Originally posted by doug:
how much does 3 phase cost to in stall plus
the inverter,per machine?</font>

05-18-2001, 12:54 AM
Read the post by Robert in the third hand section--a thread called "about motors".

I took his advice, and a vfd for 1hp is installed and going fine, driving a 3 phase motor from 1 phase 220-240v dryer circuit. The motor is a westinghouse 1hp, 208, 3.58a, in a SB lathe. The box is Hitachi solid state, limited to a 4a motor at the voltage.

It cost $219. and was shipped quickly.

The only problem is in programming to get a reverse function, and I'm sure it'll just come to me in the night what they're talking about in the instructions.

The lathe had a mechanical relay operated forward/reverse switching drum control originally, but it wouldn't energize properly with the output from the vfd either because of age or because it needed more initial current. I bypassed it and went directly to the motor and everything is good.

The company listed by Robert has a wide range of control devices available for just about any application, and their prices are lower than others.

[This message has been edited by KenS (edited 05-18-2001).]