[Tomax]

Hi!

First of all I'm far away from expert in electronics, so I'm just thinking, and asking here for some advice.

Thing is, in our company we received new cnc machine center for woodworking, and when guy who came to set up machine and do first run, he did wrong wireing on machine input switch (three phase 380v). First thing I noticed was PC computer didn't turn on, and after they changed its power supply they noticed that motherboard is damaged too. So they changed PC computer and still trying to get comunication to controler of machine (via COM port). They said that all LED control lights are ok, bit I'm starting to doubt after three days of no progress.
Is it possible that they damaged controler too? Is thare a chance that they did some damage on servos and other components? Will be liftime of machines computer (not PC) shorter (more services) ? My boss is thinking to refuse this machine and demand a new one?
Please if you have any more arguments to use on this faliure, feel fre to write down, I will appreciate.

They are giving us 12 months of waranty, but we are planing to have machine at least 5-6 years.

[Al_The_Man]

If the supply voltage was too high, it could have stressed any part of the system that happened to be powered at the time, usually the servo's and other power items have to see the controller up and ready before they are enabled.
But I would think that in light of the mistake some kind of extended warranty might be in order.
Al.

[philserveng]

First he should have checked the supply voltage, power cable diameter and phase rotation. Also, should have checked if there was a need for a neutral to be connected. usually with 3 phase neutral can be connected to ground. If the power supply needs neutral, it is possible to damage it, for the machine not to power up, or both. this guy needs to do his job right. If all is working ok, any possible damage will almost certainly happen inside 12 months warranty......so don't worry.

[Tomax]

Thanks for replays!

Today I found out more specific what was done wrong on wireing, he connected one of phase to neutral on machines input switch, and turned on.
Machine is ment to be supplyed with 380V - three phase.
Ground is connected to the body of computers box.

[Al_The_Man]

Depending on whether the neutral was actually connected back to the service ground, depends on what the neutral actually received.
If it was connected to ground it should just have blown the fuse or breaker.
If not, then anything connected to the neutral could be affected
Al.

[Tomax]

On switch's slot where nutral should be conected, was conected one of phase, and neutral was connected on slot where that phase should be.
Ground was from the start connected to locker's body, as it is right according to manual.

[Tomax]

I'm bringing up this post, because we still have problems with the machine.
They changed the computer with new one, but problem is, that in about an hour of working, computer losts the comunication with the controler, so it has to be shuted down and restarted. Another failiure happens mostly during tool changing, and it gives error of elekto spindle, and it also has to be restarted and then manualy changed. Is it possible that this are consequences of connection failiure at first time (changed phases) ???

[Al_The_Man]

Without seeing the machine wiring diagram it is difficult to diagnose what may have happened, it is not that usual, at least here, for a machine to be supplied with 3ph and neutral + ground.
Most machines I have come across require 3 phase and ground only.
I wonder why they need a neutral?
Al.

[philserveng]

I suspect something has shook loose from when the new computer was fitted. the service tech needs to come back and check the connections to/from the computer.

Neutral can be used as an option on 3 phase machines, usually where hour clocks or heaters are fitted for example. neutral can also be connected directly to ground in the machine panel.

[Mazaholic]

Sounds like you have a bad connection,or you have low DC output voltage in a power supply.
I also have never heard of 3ph with a neutral.

[nwrepair1]

Three phase with neutral is common in areas that have 208 volt panels. They are always 4 wire. The 4th wire is for ground. Never use ground wire for neutral if you are trying to run 120 volt controls using the three phase power. I've worked on industrial chinese machinery that runs on 380volts with controls that are 120volts. They always have a lug for a neutral wire to run the 120volt controls. I think that any piece of that router that is in the neutral circuit will be a problem. If the tech is using a real green wire ground to make a neutral for that machine, you will have endless electric noise problems in the control wiring. Things like freeze ups, lost programs, odd movements will be common.

[neilw20]

This sounds like gross incompetence. Get a real engineer to plan the installation correctly. Trying things will NEVER work. Analyze the WHOLE environment and interface between computer and machine.
It's easy to get smoke out. Hard to get it back in again.
We need pictures and diagrams and installation instructions to be able to help.

[thebodger@roger]

I have seen situations where there is a neutral in 3 phase supplies. It's not that all uncommon on some German and Japanese equipment. What they do is use the central WYE or STAR connection as a neutral. The only reason I can see is a possible means to "phase sync" (for lack of better term) all the single phase step down transformers in the machine. Also some local hydro regulations require that transformer secondaries be grounded on one leg. This can cause all kinds of headaches. But anyway, If your having all these issues this early in this machines life, I know I would be asking your sales rep some very pointed questions at the least. A spike to the electronics from this error in installation can cost a lot later down the road. But this is just my 2 cents.