Mitsubishi HG-AK 用户手册

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1. INTRODUCTION 
1 -  3 
 
1.3 Electromagnetic brake 
 
CAUTION
 
The electromagnetic brake is provided to prevent a drop at a power failure or 
servo 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. Use the electromagnetic brake so that 
servo motor control starts after the electromagnetic brake has completely opened. 
Be sure to check the time lag of the braking with a real machine. 
Configure an electromagnetic brake circuit so that it is activated also by an 
external EMG 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 shorten under sudden acceleration/deceleration conditions. 
 
 
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 and B2) have no polarity. 
Electr
omagnetic br
ake
Switch
VAR
B1
U
B
24 V DC
power supply for
electromagnetic brake
B2
Electr
omagnetic br
ake
Switch
VAR
B1
U
B
24 V DC
power supply for
electromagnetic brake
B2
or
 
The surge absorber (VAR) must be installed between B1 and B2. For the selection and example of 
surge absorbers, refer to "Electromagnetic brake characteristic" in the chapter of servo motor series. 
When you use a diode for a surge absorber, the electromagnetic braking time will be longer.