Had a service call today to find out why a large table saw was going through motors. Table saw is a large Jet saw used daily. Customer has went through two motors in two years, didnt think that was unreasonable considering Jet is not exactly high quality equpiment. They replaced the second Jet made motor with a Dayton motor yesterday. Saw worked for the day and then this morning they called us because the saw lacked power.
The motor is 230 Volt, single phase. I started the saw and the motor sounded like a 3 phase motor thats single phasing. Theres 240 volts at the receptacle that the saws plugged into. I checked the motor and it's wired correctly.
One of the employees was concerned because he checked for voltage and after seeing the voltage on the high leg he thought that was the cause of the problem. I explained to him the high leg can be used as long as its not a 110V circuit. The instruction sheet that came with the motor said that all voltages should be plus or minus 1% of each other. Has anyone heard of a high leg causing problems on a 230 volt motor?
I didnt get a chance to check the motor out further, by the way its acting Im thinking the start/run capacitor is dead.
"Quote: "The instruction sheet that came with the motor said that all voltages should be plus or minus 1% of each other":
Why would there be an instruction like this on a single phase motor? Something don't wash here.....
As far as I know voltage differential only matters on 3 phase motors, thats why I was confused with the instruction sheet. I dont know, maybe it is the standard sheet they put in with all of their motors.
#59215 - 11/30/0512:02 AMRe: single phase 230V motor and high leg question
"Has anyone heard of a high leg causing problems on a 230 volt motor?" Not unless some one wired into the control circuit for it...
"The instruction sheet that came with the motor said that all voltages should be plus or minus 1% of each other." I would assume that the windings design needs balance or it may over heat.... One side over powered, one under powered, just a guess...
Mark Heller "Well - I oughta....." -Jackie Gleason
#59219 - 11/30/0508:07 AMRe: single phase 230V motor and high leg question
If this is a true delta (3 transformers) it doesn't make much difference which legs you use but when this is a delta vee, with 2 transformers that wild leg can dance around a bit in relation to the other two. I hung my Dranitz on a wild leg once, set to +/- 10% and it ran out of paper overnight.
[This message has been edited by gfretwell (edited 11-30-2005).]