[mioduz]

Have a haas SMM2 ordered getting my ducks in a row. Ordered a American Rotary ADX30. I am really taken aback by the min wire size for the 3 Phase inverter.

American rotary states that the minimum wire size is 1 AWG

Checking the ampacity on that brings up 130 amp breaker. Seams like MASSIVELY overkill but anyone else want to weigh in on this??

What are you guys running?

Also American rotary also states furthor down in the manual that:

It is important to have adequate single-phase electrical service. The actual single phase current that will flow through the converter is approximately 1.73 times the three-phase current. The National Electric Code requires 2.5 times the three-phaseloadcurrent to allow for starting current and a margin of safety. This is a good conservative calculation to determine your single phase branch circuit wire size and breaker size.

Haas dictates that the machine needs a 40 amp 3 ph service. That means from what i can see that I should be able to get away with a 100 AMP breaker and i beleive 3 awg wire (if i recall)

Just trying to avoid putting a breaker over 100 amp and dealing with 1 awg wire is always a joy.

any input is appreciated

[Geof]

It is overkill but you may be stuck with it if you have to stay within Code.

I think the 2.5 multiplier for starting current and safety is based mainly on large induction motors which will draw large starting currents, but the SMM2 will only draw the 40amps because it is not running any large motors directly from the three phase input to the machine. The input is rectified onto a DC buss and the controller synthesises variable frequency AC from this to run the spindle motor and the servos.

[Machineit]

I think what he is talking about is the wire from the breaker to the convertor. They usually call for very heavy gauge wire as of course the convertor itself is a large motor.

I have a 20 and a 30 hp and it don't use anywhere near as large a wire as they would want you to. My 20 hp is hooked to the breaker with 8 or 10. My newest a 30 hp I think I used 4 or 6. I'm at home now, so can't check. Before getting the 30 hp hooked up, I ran two Haas VF-2's and a Hardinge CNC lathe off of that 20 hp convertor and 8 or 10 wire. It is all over-kill. You will never max out all of the motors and etc on the machines, just never happens.

I have a neighbor with a fabricating shop and he has a 30 or 40 hp to run a press-break and a shear, (over-kill, yes) and his "electrician," used like 00 gauge to hook his up. It is like the size of broom sticks! He could even get to go into the panel correctly! Just kind of sticks out of the box.

You will be fine with the 3 or even smaller. That said, I'm not an electrician, but I did stay at a Holiday Inn express once. You do what you feel is necessary.

Mike

P.S.: Most large motors start with a full load on them, in other words powering whatever they will power, like a hydraulic pump or lathe spindle or fan, etc. On a convertor, all that is being started is the motor itself and it is missing some of its shaft too!

M

[Ydna]

Are you going to use a 220-VAC single phase outlet? (like for a washing machine or something) The reason I ask is because I wonder how large the wires are running to the outlet. Definitely not 3-AWG, that's for sure

Being up to code is one thing, but running a 6 foot whip of giant cables into the wall where they become 1/3 the size just seems like a waste..

[underthetire]

Being up to code only matters if your house burns down and the insurance company investigates.

[D.D.Machine]

I just wired my new shop with what they called "mobile home wire" its 200amp alum hard wire. I put it in the gray pipe then did drops from the ceiling to the machines in large flex wire. when it comes to wiring do it once the right way and your done or try and cut corners and fight it for ever. you will soon find out that the wire is the cheap part of wiring a shop.

[Kool Parts]

I just wired my new shop with what they called "mobile home wire" its 200amp alum hard wire. I put it in the gray pipe then did drops from the ceiling to the machines in large flex wire. when it comes to wiring do it once the right way and your done or try and cut corners and fight it for ever. you will soon find out that the wire is the cheap part of wiring a shop.

This^
A lot of people stress out on the size of wire and the cost. Truth is "normally" you have the converter close to the breaker box. So the cost is minimal..and good insurance.
The only load you will see is the converter start up. Once it is up to speed, then the load is whatever the machine will pull, which is practically nothing. When I first put in my ST10 lathe I had a #8 So cord about 20ft long, so I used it to get started. When that lathe called for anything over 3000rpm it would droop the power just long enough to show a message on the control but it never alarmed out.
Week later I finished wired it properly and no problem.
Gary