SUPPLY POWERMASTER MODEL “GJ” GEARHEAD DOOR OPERATOR(S)

RATED ______HP, ____VOLTS, ____ PHASE FOR USE ON ROLLING SERVICE DOORS, ROLLING GRILLES AND COUNTER SHUTTERS.  MOTOR SHALL BE OF THE HIGH STARTING TORQUE, CONTINUOUS DUTY INDUSTRIAL TYPE, PROTECTED FROM OVERLOAD BY A CURRENT SENSING OR THERMAL TYPE OVERLOAD DEVICE. 

MOTOR CONTROLLER SHALL BE A HEAVY DUTY, FULL VOLTAGE. ACROSS-THE-LINE, MAGNETIC REVERSING CONTACTOR, THAT IS MECHANICALLY AND ELECTRICALLY INTERLOCKED. ELECTRICAL COMPONENTS SHALL BE INSTALLED IN A NEMA 1 ENCLOSURE.  A TRANSFORMER SHALL BE PROVIDED TO REDUCE CONTROL VOLTAGE TO 24 VAC MAXIMUM. SEPARATE TERMINAL STRIPS SHALL BE PROVIDED FOR CONNECTION OF POWER SUPPLY LINE AND ALL CONTROL DEVICES.  OPERATOR SHALL BE WIRED FOR CONNECTION OF A RADIO CONTROL, PUSH BUTTON STATION AND AN OBSTRUCTION SENSING DEVICE WITHOUT ADDITIONAL WIRING MODIFICATIONS. CONTROL CIRCUIT SHALL PROVIDE INSTANT REVERSE MOTOR WIRING. POSITIVE CHAIN DRIVEN, ROTARY TYPE LIMIT SWITCHES SHALL BE PROVIDED TO LIMIT FULL OPEN AND CLOSE TRAVEL OF DOOR.  LIMIT SWITCHES SHALL NOT BE AFFECTED BY REMOVAL OF MOTOR OR BY MANUAL OPERATION OF DOOR.    

PRIMARY SPEED REDUCTION SHALL BE BY MEANS OF AN INDUSTRIAL GEAR BOX WITH BRONZE WORM GEAR IN AN OIL BATH.  THE FINAL DRIVE SHALL BE A ROLLER CHAIN AND SPROCKET, MINIMUM CHAIN SIZE #41. THE DRIVE SHAFT SHALL BE A MINIMUM 3/4” DIAMETER AND SUPPORTED BY ROLLER BEARINGS. AN ADJUSTABLE TORQUE LIMITER SHALL BE PROVIDED ON OUTPUT SHAFT TO PREVENT OVERLOAD DAMAGE TO DOOR OR OPERATOR MECHANISM. A MANUAL DISCONNECT SHALL BE PROVIDED TO DISENGAGE OPERATOR FOR MANUAL OPERATION OF THE DOOR.  LIMIT SWITCHES TO BE CHAIN DRIVEN ROTARY TYPE AND SHALL NOT BE AFFECTED BY MANUAL OPERATION OF THE DOOR.