can I troubleshoot single phase 3hp induction motor

Hello and Thank You for the question - If you have access to an air compressor and blow gun I would start by blowing the motor out. Take a piece of rope and wind it around the pulley (or shaft) and try to "pull start" it at the same time you turn it on. If this works then the starting capacitor is bad. (the big bump on the side) Any competent motor repair shop will have a replacement. Also let me know if theres anything you forgot to mention about this. Does the motor turn freely ? If not you have an internal fan or bearings that are bad/broken. Let me know how it goes, I'm here to help

__________________
If you have found this answer helpful, please "accept" or let me know how I can be of further assistance. Thanks

the motor move,s freely but does nothing when I use the pull start. starter switch is pulled into place when on is pressed and relesed when off is pushed. still bumps with belt off but still otherwise.

Hi again , I'm sorry but I dont quite understand what your reply means. Does this motor have a magnetic switch ? What is the motor on ? What else can you tell me about the motor and switch ? Thanks - Get back to me and we'll go further with this

__________________
If you have found this answer helpful, please "accept" or let me know how I can be of further assistance. Thanks

The motor is on a shaper and the starter swich may be magnetic I'm not sure, you can see a skematic at Grizzly or Shop fox on the 3 hp shaper.the swich say's D.O.L STARTER IP 65   230V 60HZ 3HP 21A right on the front, hope this helps!

- I suspect you may also have a problem with the actual switch solenoid. My Uni-Saw acts up like this sometimes also, and I need to pull the cover on the switch and blow it out. Woodshop motors and switches need a little TLC every now and then. I just looked at the machine on Grizzly.com and I see this is a reversible unit. Does reverse work ? I would blow out both switches. When you push the switch ON does it make a "click" (maybe twice) I'm thinking you have dirty switches or maybe a bad switch? You might also consider giving Grizzly a call, they're usually pretty helpful. (570) 546-9663 or E-mail mailto:techsupport@grizzly.com (I suggest this because it may be a common problem to this shaper?) Let me know how it goes, I'm here to help

Edited by The go to guy on July 20 2006 at 12:43am

__________________
If you have found this answer helpful, please "accept" or let me know how I can be of further assistance. Thanks

reverse does the same thing and one of the first things I did was to blow everything out. One click from the switch as the contact in the switch engages, at that time there is a slite jump in the armiture then.....nothing. Also I plan to accept your response as working thru the problem with someone else ensures all avenue's have been exausted.

Good morning - If you are comfortable working with electricity, lets give this a shot -

Remove the switch cover (2 plastic screws) the buttons and face will come off together usually. There will be a small red "reset" tab - push this in- THEN to the left of the reset there will be a green dial about 1/4 - 3/8" diameter - check to make sure it is adjusted properly (for this motor it should be set to about 25) You can try turning it a little higher to see if it makes a difference. The green dial corresponds to the maximum amps the switch will allow before "tripping" (other styles used heaters (fusible links) to do the same thing)

Then try this to see if the switch is bad - First turn off the breaker to the shaper or just unplug it. Inside the switch take the HOT leads feeding the switch and either jumper them to the other side of the switch or take the HOT feed and attach to the other side of switch that feeds the motor. Turn the breaker back on (or plug it in) If the motor runs then you have something in the switch that is bad (contacts,solenoid, etc) If the motor doesn't run right away (couple of seconds) Turn off the breaker or unplug immediately !!! bypassing the switch also bypasses the thermal overload, and you dont want to let the smoke out of the motor.

If you have the time and a different motor and switch you can try a different motor on this switch (or disconnect motor and test for voltage) Or you can try a different switch. If you have another piece of equipment close enough you can run wires to it for this, just make sure you only have one motor / switch connected at once.

Let me know how it goes - It's just a matter of eliminating what does work to determine where the problem lies

__________________
If you have found this answer helpful, please "accept" or let me know how I can be of further assistance. Thanks