Here is the short story. bowl tumbler lost a lower bearing on the shaft that goes through the center of the bowl and holds the jiggle weights. I forgot to fuse my motor correctly so when the bearing failed, it took the motor with it. I replaced the bearings and got a used 1.2HP open drip motor (previous was a 1.0HP TEFC). I upsized the motor slightly because it seemed to need a tad more. Both motors are single phase cap start motors.
When the tumbler starts with the 1.2HP motor, it starts very slow and takes about 1-2min to get up to speed. With no load it zings right up. I am used to seeing about 10X the running amperage for inrush at start but the new motor only pulls about 40A on start. It then calms down to 10-12A while getting up to speed. It settles 10min later to around 7A. These motors are connected via 240 volts. My numbers look like the motor is about 50% efficient! I know the bearings are right and not in a bind. Purely a motor issue here.
I am wondering if changing the capacitor on the motor will help me get up to speed or if this is strictly a motor issue? I am sure the cap is good and working but "maybe" it could be weak? I am also wondering why the motor does not pull more power since it takes so long to get to speed. Should it not be pulling big amps to get there?
Because of the previous motor BBQ, I need to fuse this thing up. What do I need? I want to fused pretty close to load amperage so it will blow if a bearing goes again. Is there a book of knowledge on fuses and there time delays and such? Are motor fuses like breakers in that they need to be sized 20% above full load? ie, do I want an 8A fuse for a 7A load or a 10-12A?
With all these problems with stupid single phase motors, I am thinking of adding a 3ph motor and VFD so I can change the frequency of the machine. I think my bearings are all good for another 200-300 rpm. Would be nice to have the protection of a VFD too.