Product Description:

The X250 is a stepping synchronous motor built by Danaher within the Slo-Syn Synchronous Motors series. This motor converts utility-frequency power directly into indexed shaft rotation, making it a straightforward position or speed source for conveyors, metering pumps, and timing assemblies in industrial automation. By advancing 60 electrical steps per second, it provides a fixed low-speed output without a separate drive, simplifying control panels and wiring. As a self-starting design, it maintains its synchronous speed under the rated load.

The X250 accepts a nominal supply of 120 VAC at the standard 60 Hz mains frequency and is wound for single-phase operation, so it connects directly to an ordinary branch circuit. When operating at synchronous speed, it draws only 0.6 A, reducing heat in crowded enclosures. The shaft turns at 72 rpm, a speed derived from the 60 Hz input and the motor’s eight-pole construction. The minimum pull-in torque is 250 oz-in, allowing the rotor to accelerate a connected load to synchronous speed without stalling. Dynamic inertia matching is supported by a permissible load inertia of 8.8 kg-cm², allowing the motor to drive moderate flywheels or gear trains. Radial and axial forces are limited to 25 lb and 50 lb, respectively, helping the sleeve bearings remain within their intended load limits.

Proper phasing is obtained with an external oil-filled capacitor rated for 330 VAC and sized at 6.5 µF. This component shifts current between the main and auxiliary windings to provide directional starting torque. A 150-ohm series resistor rated to dissipate 50 W can be added for dynamic braking or soft-start circuits when rapid stops are required. Continuous operation is permitted in free air at temperatures up to 40 °C, while the frame temperature must not exceed 100 °C. Observing these limits helps protect the motor insulation during extended operating cycles.