Static verse Rotary phase converts for home gunsmithing

K

Keith23

Guest
I come to the well of knowledge yet again.

Using single phase power to run three phase motors.

Can anyone give me an opinion on if I need to use a rotary phase converter or can I just use a static converter to run a SB Heavy 10 lathe and a Bridgeport mill (probably never run both machines at the same time). The SB is 2 hp and the Bridgeport is 1 1/2 hp.

A rotary phase converter cost about three times that of a static phase converter. Is it worth it?

Help please!:confused:
 
I have a static converter on my SB Heavy 10 and it works fine. Look at use-enco.com I think they are around $125.00 for a 1-3 hp.

Zach
 
1-1/2 horse Bridgeport works fine with a static converter. Of course you know, you only get 2/3 of the rated horsepower with a static. It is just a starting circuit, you run on two legs of your 220v and the third motor circuit isn't powered. Gunsmithing projects don't take the heavy power these machines are designed to deliver, so 2/3 is usually okay. A cheap rotary converter can be made with a static converter and a larger 3 phase motor. Use the static to start, say, a 5 hp 3 phase motor and then switch the static converter out of the circuit, leaving the 5 hp motor running. Then run your lathe/mill in series with the 5 hp using all three legs. The 5 hp's third leg picks up power from the rotating magnetic fields of the 2 powered legs, and delivers full power to your 2 hp machine. If you don't switch the static C out after starting the (5hp) idler motor, it is possible that the static converter will "see" the additional load and kick back in at a combined load which is greater than its rating. This causes the capacitor to blow. It doesn't damage the converter, a new cap fixes it, but it smells like sh*t. I have a couple of static converters on small stuff, but what I do now is start a 10 hp 3 phase motor by spinning it up with a rubber disk angle sander against the pulley and then turn on the 220 power. I then switch in a circuit which feed all the 3 phase machines.
 
I use one static converter for my Emco lathe and small Clausing mill. Never had a problem with it and it takes up a lot less room in a small shop. Also nothing else to do but start up my machines. A rotary would probably be best but for my needs the static fits the bill.
 
Look at the Phase perfect static phase converters. They set a new standard for 3 phase conversion. We have been using since August 2005 after we wiped out 2 very expensive control systems on machining centers with the rotaries.

these static jobs will handle mucho hp. we have three machining centers (20 hp; 7.5 hp and 5 hp) plus a screw compressor (7.5 hp) plus a cylindrical grinder running on one unit.

the remainder of our machines (2 CNC lathes, 2 manual lathes, manual mill) are still running on a rotary--but that will change in near future when we replace with another phase perfect.

Jim

http://www.phaseperfect.com/
 
http://www.use-enco.com/CGI/INPDFF?PMPAGE=464&PARTPG=INLMK3&PMITEM=297-3510

I have the static $150 box that came with my 1.5 hp Delta mill.
Then I got my Clausing lathe with 3 hp and hooked them both up to the box on the mill.

It has been working great for 5 or 6 years now.

0952150-11.jpg
 
I looked in at the website. Looks excellent. I can get three phase brought into my garage by the power company for less money, but if I were farther from the grid it would be worth condisering.
 
I used one of the Enco boxes like clark shows for years to run a 2hp Chori Majestic mill and a 2hp Clausing lathe. When I bought a new Enco 14 X 40 lathe I had to switch to the rotary converter. So, to answer your question, I would think that the static converter will do what you want, but be aware that you will lose a bit (30%) of your horsepower by using it.
 
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