Electromagnetic Brake - Mitsubishi Electric HG-KN Instruction Manual

1. INTRODUCTION

1.3 Electromagnetic brake

CAUTION
The servo motor with an electromagnetic brake can be used to prevent a drop in vertical lift applications or to
ensure double safety at an emergency stop, for example. When operating the servo motor, supply power to
the electromagnetic brake to release the brake. Switching power off enables the electromagnetic brake.
(1) Electromagnetic brake power supply
Prepare the following power supply for use with the electromagnetic brake only. The electromagnetic
brake terminals (B1/B2) have no polarity.
24 V DC
power supply for
electromagnetic brake
The surge absorber (VAR) must be installed between B1 and B2. For a selection example of the surge
absorber, refer to "Electromagnetic brake characteristic" in the chapter of each servo motor series.
When you use a diode for a surge absorber, the electromagnetic braking time will be longer.
(2) Sound generation
Though the brake lining may rattle during operation, it poses no functional problem.
If braking sounds, it may be improved by setting the machine resonance suppression filter in the servo
amplifier parameters. For details, refer to each servo amplifier instruction manual.
The electromagnetic brake is provided to prevent a drop at a power failure or
alarm occurrence during vertical drive or to hold a shaft at a stop. Do not use it for
normal braking (including braking at servo-lock).
The electromagnetic brake has a time lag. Ensure enough time between releasing
the electromagnetic brake and starting the servo motor. Be sure to check the
operation delay time with an actual machine.
Configure an electromagnetic brake circuit so that it is activated also by an
external emergency stop switch.
For details of the circuit configuration and timing chart, refer to each servo
amplifier instruction manual.
While the electromagnetic brake is opened, the motor may be raised to high
temperature regardless of driving.
The life will be shortened under sudden acceleration/deceleration conditions.
B1
Switch
VAR B
U
B2
24 V DC
or
power supply for
electromagnetic brake
1 - 3
B1
Switch
VAR B
U
B2