Had a very good find a couple weeks ago on Lift 1, the six pac. It has a 900 HP DC motor driving the lift. I had been experiencing similar issues last winter, a weak motor under full load, on weekends. I had checked the basics, of course. Motor field is rated at 9 amps, and it showed 9 amps right on the drive touch screen. I was not going into 'current limit', checked that too. It ran fine on light load days, during the week. But weekends, it was a different story. If the operator needed to slow or stop the lift, they could not get going again. They were getting 'current overload' faults and couldn't get going! I went up there on Saturday morning, and it was fully loaded! Six people in every chair! Full load! That's just what I needed though, so I could troubleshoot the problem during the time it happens. Kind of scary, but necessary to do. I decided that I should go get my clamp on amp meter and verify the field amps. Even though it was showing 9 amps on the screen, I wanted to verify it. So I went and got my meter, and put it on the field leads. Wow! Sure enough, it was low, reading 6.5 amps DC current! This is almost 30 % low! I couldn't believe it! I brought it up to 9 amps that evening after shut down. Guess what? Problem solved! Been running sweetly since! No more current overloads!
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Craig's blog
The life & times of my electrical world! Archives
March 2016
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