one for the electrical engineers

[Tim Lamb]

I recently acquired a workshop dust extractor. In bits because the waste had clogged the fan and burned out the motor capacitor (single phase

2.2kW) I have no means of checking for shorted turns but the winding resistance values look OK (1.6 and 4.0 Ohms ) and it does not appear to fault to the frame.

Very much a dead parrot moment except there is no means of guessing the original rating.

ISTR a thread on this subject and will look when I have more time. However, it occurred to me that someone might have a similar unit and could look up the values for me.

Alternatively given that this is a large diameter steel! fan is it possible to determine the rating by any other means?

regards

[Andrew Gabriel]

I doubt that caused the capacitor to burn out. It was probably going to burn out anyway.

Normally doesn't matter very much -- mainly affects the starting torque, and a fan probably doesn't have much initial resistance.

Is it not written on the rating plate? What is written on the rating plate?

[Tim Lamb]

In message , Andrew Gabriel writes

No but there is a lot of inertia in such a heavy fan.

Power 2200W phase 1

Volt 230V HZ 50

Amp 9.6A Class B

RPM 2950 SER

All fairly self explicit except *SER*. I tried spinning the motor with string wound round the shaft (might have the direction wrong) and could not hear any centrifugal switch clicks.

There are no access plates and I don't want to draw the end covers off unnecessarily.

Perhaps the first move is to borrow a capacitor from another motor and try livening it up on no load. If the supply trips out I can show it to my local rewind firm and then decide.

regards

>

[Chris Hodges]

I would think this is short for serial number - probably worn off by now or stamped but not deep enough to read.