Phase Converter, Transformer, and Controller Issues with a Big Moulder

Troubleshooting power conversion and startup problems with a complicated electrical arrangement. January 25, 2010

Question
Can you run a Weinig moulder on a phase converter? The moulder allows each motor to start separately, and each of the four motors is 10hp to 15 hp. The phase converter is 50hp. The problem is that I am trying to bring this machine online and am not able to get some of the panel switches to respond, including the ATS controller. I can turn them on with the magnetic starters in the panel (ATS excluded). I'm wondering if I have a voltage issue as a result of the phase conversion, but I can't find it. I also run a 15 hp chip blower which runs through the same phase converter and 440v transformer as the moulder, and several other 3 phase pieces of equipment that do not run through the transformer and also all work fine. I don't run any of them while trying to trouble shoot the moulder.

The ATS was serviced by Weinig before I bought the moulder. At that time, it had dedicated 3 phase power. The moulder has been out of service for a year in my shop before I tried to bring it online. It may be time to bring in a Weinig tech again, but it’s a lot of expensive travel that I'll be billed for, and if it turns out to be power related, they might not be able to help anyway. I appreciate your ideas here. If you are near Tacoma, WA and have some experience troubleshooting these issues, let me know.

Forum Responses
(Solid Wood Machining Forum)
From contributor V:
I have an SCMI molder and I run it on a 25 hp phase. It has 18 hp and two 12hp and feed motor and the 7hp for the dust and runs fine. I would suggest starting the motor with the most draw on it. For me it’s the side spindles because they are together.


From contributor S:
The first thing you need to do is check the actual voltage on each line going into the machine, if I read what you are trying to say correctly. You can press the contacts together and this makes the motors run. If this is the case, then you need to check the coils and aux contactors on the machine. Since that is what actually starts the motor starter and keeps it on until you press the off switch. Chances are that the coils for the starters and the ATS system are being run from a separate step down control transformer mounted in the electrical control panel box. You can look at one of the starters and check to see what the coil voltage is. There should be a little tag on the coil that shows the voltage. If the machine is setup for 440 volts and the coil reads 110 or 220 then you have a step down transformer. You can power up the machine and check the voltage coming out of the transformer or the coil contacts to see if there is any power and what the current is. You also may want to go over all of the connector terminals (with power off of course) and make sure they are all tight. It wouldn't be the first time someone left one loose and it is not making contact very well. If nothing else works, why don't you just call Weinig and talk to the service dept. I am sure that can walk you through some checks without having to send someone out.

From contributor F:
Your transformer isn’t large enough to run both machines. We run a 70 hp six head molder and a ten hp blower with a 25hp phase converter. If you can rewire your blower to 220v and use your trans for the molder be sure the trans is large enough for the application.


From the original questioner:
I'll check the transformer. I'm not running the dust collector at the same time while I test the moulder, and I think the transformer is way oversized for the job, but maybe not. I'll look at that.

Contributor S - I did try Weinig, but no answer on the phone several times, and no response to email. Odd, but I'll keep trying. There is a step down transformer. I do have one leg that has a higher than expected voltage - the generated leg is about double the others. I've tried swapping that generated leg around to the different leads, but no change.

Contributor V - I'll try changing the order, but I think I have something else going on. I can't get the feed rollers to start from the panel switch, but I can toggle them from the starters. That might just be a bad switch or starter, because that is a lower hp motor. I do get a minor plastic burning odor from an overheated wire or switch, along with a puff of smoke once. I'm trying to identify which part is doing it to see if it will be a simple replacement.


From contributor U:
I run a 5 hp phase converter for my grinders as well. I had the same problems you are having. I also had a leg that was higher than the others. Mine has a frequency invertor that controls the speed of the grinding wheel.

1. The frequency invertor has protection inside to not be able to run if the voltage is higher by + or - 10%. These are internal and made this way to save you from buying these over once they are cooked! I am not sure if you have a frequency invertor even on your machine.

2. Bought a buck - boost system to stabilize the man made leg to bring the power to within the limits of the invertor. I have not had a problem for over eight years now. I suspect the ATS system has some sort of protection form the high leg and stops other things from working correctly.

Hire a pro, the money you will save is your own. You could do more damage to the machine and end up costing you more money in the long run.


From the original questioner:
I think I've narrowed this issue down to the 440 volt transformer after the phase converter. I'm only getting 300 volts. Enough to start all the motors on the moulder, but not apparently good enough for the ATS controller. I'm trying to figure out my transformer issue. All the tabs are low in voltage. I think it might be a simple wiring issue. The equipment seller was supposed to pre-wire the transformer to the phase converter and didn't (though he did charge me for it). I may have made a simple wiring mistake. Thanks for your help.

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