new mill power and wiring

[stanglou]

Ok, the new mill states that it must have 230V three phase power. is this true, and if I have 240 what should I do. There is also a five wire plug that the machine was attached to, what is with that, none of the diagrams mention a fifth wire....im confused

[Tony Montana]

I'm no expert, but since no one else has chimed in I'll take a stab at it.

The 230 volt requirement is a nominal spec. Voltage varies from locality to locality and even from day to day. 240 should be fine.

Again, I'm no expert but perhaps the fifth wire is a neutral (3 hots, one ground, and one neutral). I've seen this sort of thing with 220 single phase welders. Instead of the normal 3 wire (2 hots, one ground) they often have a neutral wire as well. The neutral is only necessary if the machine taps one leg for a 110 application (such as a machinist light, a duplex outlet, dro, etc).

[Flyinfool]

Also most houses do not have 3 phase wiring.
You will need to get a Phase converter. The motorized ones are the best.

[in2steam]

Originally Posted by stanglou Ok, the new mill states that it must have 230V three phase power. is this true, and if I have 240 what should I do. There is also a five wire plug that the machine was attached to, what is with that, none of the diagrams mention a fifth wire....im confused

This question was answered already in a different area,

230 three phase and 240 are the same thing, its a nominal rating, some machines have taps on there transformers to give a closer voltage if needed on the control side. The fifth prong was an reported as an extra "neutral" since 3 phase systems don't normally use a neutral its probably a ground.
although I don't know fore sure.
220 is normal res. wiring for the US, this is single phase, people often refer to this in three phase, but its very rarely that, its almost always near 240. There is a 208 volt three phase but this not used in too often anymore as its prefered for lighting systems. You(more so the power company) can adjust your voltage on nearly any AC system to suit your needs at the transformers, typically its better to have more votlage then less.

With a good meter (one which reads RMS) you should near 230 volts, 240 is ok. A cheap $30 meter will read RMS aproximations and they tend to high you might see something like 265. Depending upon how your service is grounded(and transformer) you may see 0 votls across the b phase(L2), All electrical equipment is rated with a 10% variance, so thats 2o votls in each direction.
As always if you find yourself reading this.....
If you are unsure hire a professional, don't take a chance wasting your money, time, and possibly your or someones life in error.
chris

[in2steam]

delete

[J. R. Williams]

Stang
I have a Tree Journeyman 250 and operate it on single phase 240 volt power. The power feeeding the mill uses the three lines coming into the unit (L1, L2, L3)with two going to the main controls system(L2, L3) and the third line (L1) goes along with the other two to the unit's VFD. The other lines are the Neutral and Ground The motor is rated at three HP and the VFD is a 5 hp rated unit. I was told by the local vendor the unit had to run on three phase and bought a CNC rated rotary converter. After several times starting the unit and forgetting to start the converter I decided to remove the converter. It has been in service for many years and no problems running on single phase 240 volt power. Tree said 'no converter, no warranty'.
JRW