re-occurring electrical issue with this 2021-2022 Wood-mizer BMS250MU

[jimbarry]

20230327 Wood-mizer BMS250MU electrical issue again - YouTube

[KenMac]

I have no personal experience with any WM equipment, so take this with a grain of salt. My experience with commercial HVAC equipment tells me that IF the switches are also circuit interrupters they probably will have to cool off before they will reset. This is also assuming that heat is the cause of the switch opening. Generally, heat causes most types of circuit interrupters to open, even if amps are too high. This is just what came to mind when I watched your video. 

[MattM]

Jim if you haven't fixed it yet try switching around the emergency stop switch's on your machines.
On your video you were losing power to both switch's and the emergency stop is what feeds them. Going by the schmeatic they also don't look to be those magnetic type switch's that trip when they overheat but the emergency one I think is.

That's definitely the easiest trouble shooting and should only take a few minutes to check  

If that's not the issue then change around the other two switch's. Power goes to the right-hand switch first and then from there to the left-hand. So if one of those is failing it would have to be the right hand switch to affect both. If you switch them then only the left should cut out.

[terrifictimbersllc]

Assuming that the blade getting too close to the sensor isn't what's turning it off. 

[MattM]

He already checked the sensor in the video and from what I could see never touched the blade again after checking for interference.

[terrifictimbersllc]

Sure. Doesn't have to touch though,blade just coming near like magnet does, will stop machine.

[MattM]

Yes I know.... I have a bms250 too. What I was getting at is that in the video he clearly checked the sensor for interference. The machine did not start working again. He didn't touch the blade again yet a few minutes later the switch's had power. If it was the sensor then his power would have come back after he pulled the blade away. Also he has two of these machines, uses them regularly, and from what I can remember he's had his first one for quite some time and is a very competent man ... So he knows about the sensor. But his second machine is from the bad batch that woodmizer was sending out to people during the height of the worldwide 6!@#%^&*$how and it wouldn't be surprising if there were bad batches of parts floating around at that time. It might have nothing to do with the switch's and could be something else inside that is the problem but there's a good possibility that it is and switching around a couple.of switch's is a very quick way to narrow down the problem and much easier that breaking out a multimeter for anyone that isn't great at electrical troubleshooting  8)

[MattM]

@jimbarry  just wondering if you figured out the problem yet??? 

[jimbarry]

Haven't had time to re-visit. I've been talking with a fellow over on the ArboristSite. He did some digging on the two 'finder' brand relays on that second sharpener. The first sharpener uses 'relpol' relays. He looked them up and according to him, the finder replays are meant for the Euro market. The relpol ones are meant for North America.  The P1 finder relay does not appear to function like the relpol relay.
That's about where I am at with it at this point.

As for the magnet sensor shut off switch. The magnet is no where near the sensor when this issue occurs. And there's no bend in the blade that would bring it close enough to the sensor to trigger it. As I said before, when I do eventually get this machine going again, it completes several cycles of sharpening on that particular blade where it behaves as it should.

I just want to point out, in case someone from Wood-mizer is reading this, that just because I got this machine working again does not mean everything is ok. There's clearly an issue with this production model. I fully expect this issue to appear again. My suggestion again would be to send both relpol relays to replace the finder relays. Seems like a logical place to start in my opinion. Yet, WM chose to ignore that request.

[PAmizerman]

I had a bad solder joint on the rectifier that drove me crazy for a while until I finally found it.

[jimbarry]

Anybody have a copy of the electrical manual for this machine? The 110v machine, not the Euro model.

[terrifictimbersllc]

 

 

 

[terrifictimbersllc]

Sorry for quality see if I can improve it tomorrow

I have attached a better PDF of the BMS250MU electrical diagram and parts legend that goes with it. 

[jimbarry]

This forum's software reduces resolution of images so it will difficult to share here. I'll send you a message with my email. Thanks.