Korea Ever-Power · Y2EJ Series · Hoist and Crane Drive Guide

When power is removed from a standard induction motor, the rotor decelerates due to friction only. There is no regenerative braking action without a power supply, and the motor provides no meaningful retarding torque below approximately 20% of synchronous speed. A hoist motor without a mechanical brake will allow the load to descend under gravity at a speed limited only by rope speed and friction — typically 0.5 to 2.0 m/s for a standard workshop hoist.

An external brake mounted on the hoist gear output shaft or on the load chain drum requires separate mounting, alignment, and control wiring. The brake must be connected to a control signal that coordinates exactly with motor contactor operation — any timing error between motor de-energisation and brake engagement allows load drift. External brakes on hoists also require periodic manual adjustment and are more susceptible to contamination from the crane environment than an integral motor brake.

The Y2EJ brake motor integrates the motor and brake into a single sealed unit sharing one terminal box. The brake DC supply is derived from the same three-phase supply as the motor through an internal rectifier, ensuring the brake releases simultaneously with motor energisation and engages simultaneously with motor de-energisation. There is no external brake wiring, no separate mounting, no timing relay, and no alignment procedure. The integral design eliminates all the coordination failure modes of external brake systems.

The motor runs for a defined on-time then stops for a rest time, repeating at regular intervals. The Y2EJ motor nameplate power at S3 duty is rated at a specific cyclic duration factor (CDF) — typically 15%, 25%, or 40% on-time. A Y2EJ motor rated 1.5 kW at S3 25% CDF can produce 1.5 kW during the on-period provided each on-period does not exceed the rated time and the off-period provides adequate cooling. Hoist and crane duty typically falls in the S3 25% to 40% range for normal warehouse and workshop operation.

S4 duty accounts for the thermal losses during frequent starting as a significant portion of total motor heating, not just running losses. For intensively cycled cranes making more than 60 lifts per hour — steel plant cranes, container cranes, and high-throughput industrial cranes — the motor must be selected for S4 duty or the starts per hour must be verified against the Y2EJ maximum permissible starting frequency. Korea Ever-Power Y2EJ series motors are rated for up to 240 braking operations per hour in continuous cyclic service.

The Korea Ever-Power Y2EJ series brake motor is the standard specification for chain hoists, workshop overhead cranes, jib cranes, and monorail hoists. The integral spring-applied electromagnetic brake provides a static holding torque of 1.5 to 4.0 times rated motor torque depending on the size and brake model selected — covering the full range from light workshop chain hoists through heavy-duty production crane applications. The full Y2EJ range is available in the brake motor product section.

For hoist applications requiring very fast stop times (below 0.15 s for man-riding) or for crane bridges where long cross-travel distances require accurate stopping at shelf positions, Korea Ever-Power recommends contacting the technical team for a motor brake system sizing specific to the application duty class, rope system, and required stop distance.

Workshop jib cranes and pillar-mounted slewing cranes up to 2 t use Y2EJ 0.37 to 2.2 kW for hoist, and separate Y2EJ or standard motors for the slewing drive. Compact 4-pole Y2EJ fits within the standard hoist trolley envelope without increasing crane hook path dimensions.

Monorail hoist systems in automotive assembly, food processing, and warehouse pick-and-place use Y2EJ 0.18 to 3.0 kW with precise stopping for positioning at work stations. Brake motor ensures load does not drift between work stations when hoist motor stops.

Dock leveller lip and platform drive motors require fail-safe braking to hold the leveller at any intermediate position during vehicle loading. Y2EJ 0.37 to 0.75 kW with 2.0 times brake torque is the standard specification for powered dock leveller drive units.

Goods lifts and mezzanine freight lifts (not passenger lifts) use Y2EJ brake motors with 2.0 to 3.0 times rated brake torque. The Y2EJ 4-pole 0.75 to 5.5 kW range covers goods lifts up to approximately 500 kg SWL with standard travel speeds of 0.15 to 0.30 m/s.