Informational Brochure

Switch Operating Mechanisms - Electrical MO-10 Motor Operator

The MO-10 is an aluminum housed, partial revolution motor operator for actuating switches with either direct or offset torsional controls. Typical applications include remote operation of air-break disconnect switches, operation through supervisory control, or in conjunction with automatic transfer or sectionalizing schemes, or in combination with high- speed grounding switches for automatic isolation of transformer faults. The MO-10 is available with a wide range of torques and operating speeds as shown in Table 9. The voltage supply may be dc (24, 48, 125, and 250) or ac (120, 240). Because of this range of operating torque, the MO-10 may be used with Pascor Atlantic switches rated 8.3 thru 800 kV. Manual Operation The MO-10 may be manually operated by inserting the handle through the access port of the gear cover. To insert the handle, the Manual Operation Disconnect Lever must be moved to the side which electrically disconnects both motor and control circuits. Manual operation is through a 62:1 worm gear on 375:1 and 594:1 motor operators and through an 80:1 worm gear on 760:1 motor operators. Motors and Gear Drives The MO-10 motor operator is available in a variety of combinations of motors and connecting gear drive ratios see Table 8 & 9. The standard dc motor unit is rated ¾ hp, 1750 rpm and includes a 375:1 gear drive. For AC applications, the motor circuit utilizes a rectifier to convert the AC input to DC. Dynamic Braking is accomplished through a braking resistor in the DC motor circuit. Other combinations of motor rating and gear drive assemblies are tailored to satisfy specific output torque and/or speed requirements. All motors have high starting and running torques at minimum IEEE voltages, are sealed against moisture, dust and fumes, and require no lubrication. The motor circuits are protected by class cc fuses, which permit locked armature current flow for a short period.

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