FS41 ES jointer/paner starting issue

[roger wiegand]

Here's a few second video of what the machine is doing:

https://www.youtube.com/watch?v=FzzQpWVQLnw

After I've been using my planer for a while and stop it to make an adjustment or switch between planing and jointing I often have an issue re-starting it. It comes almost up to speed and then shuts off. If I let it sit for just a minute or two it will then start normally. It never has this problem on a "cold" start.

It is a three phase machine, power is coming from an American Rotary AD20 rotary phase converter. Voltages are within range (as measured with no load).

Any hints about what might be going on? It's irritating, but I can live with it. I'd rather not do anything that will damage the machine, and of course if it gets worse that's a bigger problem. I did not see this in the first year or so that I had the machine, it's been doing it for a couple months now.

[Rod Sheridan]

Hi, I would start by measuring the voltage while it starting on all three phase pairs( A-B, B-C, C-A).

You’ll have to start it three times as you will have to reconnect the meter unless you have a three phase analyzer....Rod

[Bill Dufour]

Motor Hp vs rpc hp? I see a spark at the start switch as it shuts down. I can not read the red numbers. Do they change or what do they indicate? RPM-Amps.
It seems like the motor is drawing too many amps on startup and the overloads kick out. Any sign of bad bearings getting troo

[roger wiegand]

Hi, I would start by measuring the voltage while it starting on all three phase pairs( A-B, B-C, C-A).

You’ll have to start it three times as you will have to reconnect the meter unless you have a three phase analyzer....Rod

Stupid question I'm guessing, but how do you do that? Where do you measure? Do you need a voltmeter that can be connected directly into the circuit somehow so that it passes the required current? I'm pretty sure my little $30 meter isn't up to that!

[roger wiegand]

Motor Hp vs rpc hp? I see a spark at the start switch as it shuts down. I can not read the red numbers. Do they change or what do they indicate? RPM-Amps.
It seems like the motor is drawing too many amps on startup and the overloads kick out. Any sign of bad bearings getting troo

Motor HP is 7.5, the RPC is 20 Hp. It's on a 60 amp circuit; all done per the manufacturers recommendation.

The red numbers are the DRO for the planer thickness. I'll have to look in the book to see if they will show anything else. Yes, it is acting as though some kind of overload is being activated. The planer is only a couple years old with really minimal use for a machine of this kind. Bad bearings at this point would be a real disappointment!

There is a light in the switch that comes on when the machine is running. What you're seeing as a spark I think is that light flashing on just as the motor cuts off.

It seems funny that it only happens in a small window after the machine has been running for 15-20 minutes.

[Steve Rowe]

Here's a few second video of what the machine is doing:

https://www.youtube.com/watch?v=FzzQpWVQLnw

After I've been using my planer for a while and stop it to make an adjustment or switch between planing and jointing I often have an issue re-starting it. It comes almost up to speed and then shuts off. If I let it sit for just a minute or two it will then start normally. It never has this problem on a "cold" start.

It is a three phase machine, power is coming from an American Rotary AD20 rotary phase converter. Voltages are within range (as measured with no load).

Any hints about what might be going on? It's irritating, but I can live with it. I'd rather not do anything that will damage the machine, and of course if it gets worse that's a bigger problem. I did not see this in the first year or so that I had the machine, it's been doing it for a couple months now.

Roger, I have the same machine but with a 5.5 HP motor and is a 2007 model. I had a similar problem in the first year of ownership but it would only happen intermittently after the machine had been running for a while (whether under load or not). I have two recommendations other than calling MiniMax technical support.
1) Verify that your control circuit is not powered from the generated leg of your phase converter. The 'wild' leg voltage will be excessively high until the phase converter is under load and this will play havoc with control circuits. You should be able to figure this out from the wiring diagram in your manual.
2) The main power switch has a thermal overload setting. Mine was set on the light side so I just adjusted it a bit higher and my problem was solved. Before I did this, I contacted SCM Technical Support and found I knew more about the machine than the tech I talked with. His solution was to just send me a replacement switch with the same setting which would not likely have solved the problem. It may be worth trying in your case since your machine is no longer under warranty.
Hope this helps,
Steve

[roger wiegand]

Mine might be 5.5 hp as well, I looked it up on the web rather than reading the nameplate. I bought the machine used, so assumed I had no warranty coverage. No reason to find out before now.

These both sound like very reasonable things to look at that would be quite consistent with the symptoms, especially the phase thing with the controlling circuitry, as I paid no attention as to which was which when I wiredit. I'll check that today. Thanks!

Roger, I have the same machine but with a 5.5 HP motor and is a 2007 model. I had a similar problem in the first year of ownership but it would only happen intermittently after the machine had been running for a while (whether under load or not). I have two recommendations other than calling MiniMax technical support.
1) Verify that your control circuit is not powered from the generated leg of your phase converter. The 'wild' leg voltage will be excessively high until the phase converter is under load and this will play havoc with control circuits. You should be able to figure this out from the wiring diagram in your manual.
2) The main power switch has a thermal overload setting. Mine was set on the light side so I just adjusted it a bit higher and my problem was solved. Before I did this, I contacted SCM Technical Support and found I knew more about the machine than the tech I talked with. His solution was to just send me a replacement switch with the same setting which would not likely have solved the problem. It may be worth trying in your case since your machine is no longer under warranty.
Hope this helps,
Steve

[Jim Becker]

You might want to touch bases with Sam Blasco to get his input on what to look for.

[Rod Sheridan]

Roger, I have the same machine but with a 5.5 HP motor and is a 2007 model. I had a similar problem in the first year of ownership but it would only happen intermittently after the machine had been running for a while (whether under load or not). I have two recommendations other than calling MiniMax technical support.
1) Verify that your control circuit is not powered from the generated leg of your phase converter. The 'wild' leg voltage will be excessively high until the phase converter is under load and this will play havoc with control circuits. You should be able to figure this out from the wiring diagram in your manual.
2) The main power switch has a thermal overload setting. Mine was set on the light side so I just adjusted it a bit higher and my problem was solved. Before I did this, I contacted SCM Technical Support and found I knew more about the machine than the tech I talked with. His solution was to just send me a replacement switch with the same setting which would not likely have solved the problem. It may be worth trying in your case since your machine is no longer under warranty.
Hope this helps,
Steve

I'm expecting that his control circuit is fed from the derived phase and is collapsing under starting current.

That's why I wanted the OP to measure the incoming voltage.........Rod.

[roger wiegand]

Been busy with another project and haven't had a chance to open things up and try to trace the wires. Maybe today.

[roger wiegand]

SOLVED!

Thanks for your help. Switching which phase was attached to which lead was the key. A clue for anyone who has this problem in the future is that when wired correctly the line voltage is passed to the machine on two wires and the electronic displays are on even with the RPC is turned off. If it is fed with the generated phase then the electronics go off when the RPC is turned off.

[Steve Rowe]

SOLVED!

Thanks for your help. Switching which phase was attached to which lead was the key. A clue for anyone who has this problem in the future is that when wired correctly the line voltage is passed to the machine on two wires and the electronic displays are on even with the RPC is turned off. If it is fed with the generated phase then the electronics go off when the RPC is turned off.

I am glad that solved your issue. I do find it disturbing that you have line power to your machine when the RPC is off. You really need to run from a single power source through a single disconnect or breaker either upstream or downstream of your RPC. Check with your local code but the configuration you describe could be a potential hazard to you and/or your machine. The same two lines that power my phase converter also provide power to all my 3 phase machines and I run it through a 3 phase breaker panel.

[roger wiegand]

The person at American rotary explained that apparently there are CNC machines that require the 240V single phase power all the time, so that's how they build them.

I don't lack for disconnects. There's a power switch on the machine that controls all three phases, and a plug from the machine into the three phase outlet, a three-phase breaker for the circuit on the output side of the RPC, and a single phase breaker on the input side of the RPC.

[Steve Rowe]

That's good to hear.