120 VOLT A/C MOTOR

[zipthetrip]

I HAVE A 120 VOLT, FRACTIONAL HORSEPOWER MOTOR THAT DRIVES A SMALL CONVEYOR. THE CONVEYOR MOVES WAY TOO FAST AND I NEED TO SLOW IT DOWN AS CHEAPLY AS POSSIBLE, CAN I USE A SIMPLE CEILING FAN RHEOSTAT TO CONTROL THE SPEED OR DO I NEED TO CHANGE TO A DC MOTOR WITH AN INVERTER.

 

[Barry1961]

Your output torque is going to drop very quickly when you start reducing the speed of the single phase motor you have. Just as a ballpark if full load rpm is 1500rpm you would have around 90% torque at 1000rpm and 50% torque at 500rpm to ????

If "way too fast" is more than a 30% reduction in speed you are going to lose a lot of your torque.

This is a ballpark and will vary from motor to motor with the same controller.

Barry1961

 

[motorsdirect]

IS THIS A SINGLE OR 3PH MOTOR.....I AM ASSUMING 1PH.....IF SO WHAT SORT OF MOTOR IS IT.....ie. DOES IT HAVE A CENTRIFUGAL SWITCH INSIDE??? OR A STARTING RELAY??
IF NOT...IT MAY BE A PERM.CAP TYPE 1PH MOTOR...WHICH TO SOME EXTENT, WOULD BE CONTROLABLE.I WILL WAIT FOR YOUR REPLY!

JEFF

http://www.motors-direct.co.uk

 

[zipthetrip]

THIS IS A SINGLE PHASE 110 VOLT, PERM. CAPACITOR TYPE MOTOR.

 

[motorsdirect]

FAIRLY EASY TO SPEED CONTROL....TO AN EXTENT!!!
THE EASY WAY IS AS FAN SPEED CONTROLS WORK...PROBLEM WITH THIS METHOD BEING THAT,FANS RUN UNDER A SET LOAD!!
IT WILL BE TRIAL AND ERROR REALLY..AND WILL DEPEND HOW MUCH YOU WANT TO SLOW IT DOWN....REMEMBERING THAT THE COOLING WILL SUFFER WHEN THE MOTOR SLOWS!!SO MAYBE SOME SORT OF EXTRA COOLING.
YOU WILL NEED TO SEPERATE AND IDENTIFY THE START AND RUN WINDING LEADS...CONNECT YOUR CAPACITOR IN SERIES WITH THE START WINDING ONLY!
THEN, YOU WOULD SUPPLY THE START WINDINGS AND CAP WITH THE FULL 110 V CONSTANT. AND WOULD SUPPLY THE RUN WINDINGS SEPERATELY,WITH A VARYING OR LOWER VOLTAGE TO VARY THE SPEED.
KEEP A CHECK ON THE MOTOR CURRENT,AND MAKE SURE IT ISNT GETTING TOO HOT!!!
AS I SAID...WORKS WELL ON FANS...CONVEYERS??? TRIAL AND ERROR.
WILL DEPEND ON THE VARIATION OF LOAD..AND HOW SLOW YOU NEED IT TO RUN!
HOPE THIS IS OF USE
JEFF

http://www.motors-direct.co.uk