3. SIGNALS AND WIRING 
3 -  38 
 
3.10 Servo motor with an electromagnetic brake 
3.10.1 Safety precautions 
 
CAUTION 
Configure an electromagnetic brake circuit which is interlocked with an external 
emergency stop switch. 
Servo motor
Electromagnetic brake
B
RA
Contacts must be opened
with the emergency stop switch.
Contacts must be opened when ALM
(Malfunction) or MBR (Electromagnetic
brake interlock) turns off.
24 V DC
U
 
The electromagnetic brake is provided for holding purpose and must not be used 
for ordinary braking. 
Before operating the servo motor, be sure to confirm that the electromagnetic 
brake operates properly. 
Do not use the 24 V DC interface power supply for the electromagnetic brake. 
Always use the power supply designed exclusively for the electromagnetic brake. 
Otherwise, it may cause a malfunction. 
When using EM2 (Forced stop 2), use MBR (Electromagnetic brake interlock) for 
operating the electromagnetic brake. Operating the electromagnetic brake without 
using MBR during deceleration to a stop will saturate servo motor torques at the 
maximum value due to brake torque of the electromagnetic brake. This can result 
in delay of the deceleration to a stop from a set value. 
 
POINT 
 
Refer to "HG-KN_/HG-SN_ Servo Motor Instruction Manual" for specifications 
such as the power supply capacity and operation delay time of the 
electromagnetic brake. 
Refer to "HG-KN_/HG-SN_ Servo Motor Instruction Manual" for the selection of 
a surge absorber for the electromagnetic brake. 
 
Note the following when the servo motor with an electromagnetic brake is used. 
 
1)  The brake will operate when the power (24 V DC) turns off. 
 
2)  Turn off the servo-on command after the servo motor stopped.