- Joined
- Aug 3, 2017
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- 2,437
About a month ago, I brought home my new mill, powered by a 3 phase 3 hp motor on a static phase converter. I got it fired up right away, and it seemed ok!
A few times it seemed to 'surge' trying to start (that is, trying to turn, going backwards, then starting again) for a few seconds, which i thought might be a problem with the variable speed head, but didn't bother much with it. It also took a while to start up, but I figured that was just the way it was. The last time I used it, I noticed it slowed down while drilling a hole, but I figured perhaps I was being an ape on the handle and just mashed on the handle to hard. Also, I figured I was running on a static covnerter, which meant 2/3 the power, so perhaps that? It was running my mills fine it seemed, so I didn't think much about it. Additionally, the previous owner mentioned he thought it was 'pretty low powered', but assumed he was just use to the commerical ones he used, so I partially figured that chinese motors just lie a bit about hp.
However, today I was doing a pretty simple operation: Drilling 4 1/2" holes, and it was all but stalling on the exit of the hole! Additionally, I tried running a 1.5" hole saw, and it couldn't make much of a cut at all without it completely stalling. At the point, I was concerned, as despite it being a SPC, the 3 hp motor should STILL run better than my old 1hp Millrite.
Additionally, I noticed the variable speed head casting was quite warm. I didn't know what to expect, but I wanted to check it out anyway. I pulled the side off and noticed that it was basically unused inside, there was nothing to explain the issue. THEN, as I was getting off the milk crate I needed to reach the head, I put my hand on the motor. IT was hot to the touch!
At that point, I figured something must be amiss. BUT, 3 phase motors are dirt-simple, what could be wrong? The data plate caught my eye, and I saw the wiring diagram, and "wondered".
I never bothered checking the wiring, since the sticker on the motor said "wired for 220v" and the cover for the wiring panel had never been touched (the factory 'sticker' was still over it!).
I pulled off the cover, and with a little study, it was obvious it was wired for High Voltage! A few minutes of work, and I buttoned it back up.
The motor started much faster, and sounded much better. It seemed to be turning faster, so I suspect it was running quite a bit slow on low voltage!
I hope I/the previous owner didn't end up harming the motor too much, but it still seems to work fine.
So my lesson today: Don't just trust that the previous owner/manufacturer wired your motor up right, check it! Every other machine in my shop I ended up pulling the wiring box apart to check/confirm it was right, since I didn't trust previous owners(they are all older machines)... This one was basically brand new with an owner who barely touched it, so I figured "that sticker says 220v, it must be 220v!"
A few times it seemed to 'surge' trying to start (that is, trying to turn, going backwards, then starting again) for a few seconds, which i thought might be a problem with the variable speed head, but didn't bother much with it. It also took a while to start up, but I figured that was just the way it was. The last time I used it, I noticed it slowed down while drilling a hole, but I figured perhaps I was being an ape on the handle and just mashed on the handle to hard. Also, I figured I was running on a static covnerter, which meant 2/3 the power, so perhaps that? It was running my mills fine it seemed, so I didn't think much about it. Additionally, the previous owner mentioned he thought it was 'pretty low powered', but assumed he was just use to the commerical ones he used, so I partially figured that chinese motors just lie a bit about hp.
However, today I was doing a pretty simple operation: Drilling 4 1/2" holes, and it was all but stalling on the exit of the hole! Additionally, I tried running a 1.5" hole saw, and it couldn't make much of a cut at all without it completely stalling. At the point, I was concerned, as despite it being a SPC, the 3 hp motor should STILL run better than my old 1hp Millrite.
Additionally, I noticed the variable speed head casting was quite warm. I didn't know what to expect, but I wanted to check it out anyway. I pulled the side off and noticed that it was basically unused inside, there was nothing to explain the issue. THEN, as I was getting off the milk crate I needed to reach the head, I put my hand on the motor. IT was hot to the touch!
At that point, I figured something must be amiss. BUT, 3 phase motors are dirt-simple, what could be wrong? The data plate caught my eye, and I saw the wiring diagram, and "wondered".
I never bothered checking the wiring, since the sticker on the motor said "wired for 220v" and the cover for the wiring panel had never been touched (the factory 'sticker' was still over it!).
I pulled off the cover, and with a little study, it was obvious it was wired for High Voltage! A few minutes of work, and I buttoned it back up.
The motor started much faster, and sounded much better. It seemed to be turning faster, so I suspect it was running quite a bit slow on low voltage!
I hope I/the previous owner didn't end up harming the motor too much, but it still seems to work fine.
So my lesson today: Don't just trust that the previous owner/manufacturer wired your motor up right, check it! Every other machine in my shop I ended up pulling the wiring box apart to check/confirm it was right, since I didn't trust previous owners(they are all older machines)... This one was basically brand new with an owner who barely touched it, so I figured "that sticker says 220v, it must be 220v!"
That was 6 hrs of busting arse with my boss and partner .
Even after 20 seconds of running it, it is way better off than before! I can't help but wonder if the factory mis-wired it, or the company that assembled it for the PO wired it wrong, but I'm glad I caught it. It was just too ridiculous for a 3 hp 3 ph motor to be underpowered compared to my battery powered drill, so I had to check!