12 - 2
12. SERVO MOTOR
12.1.3 Electromagnetic brake
CAUTION
The electromagnetic brake is provided for preventing a drop at power failure or at
servo alarm occurrence during vertical drive, or for holding a shaft at stop. Do not
use it for normal braking (including braking at servo lock).
The brake has a time lag. Use the brake so that servo motor control is started after
the brake has completely opened.
Configure the electromagnetic brake operation circuit which interlocks with an
external emergency stop switch.
Refer to section 3.11 for details of the circuit configuration and the timing chart.
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 performing servo motor operation, supply
power to the electromagnetic brake to release the brake. Switching power off makes the brake effective.
(1) Electromagnetic brake power supply
Prepare the following power supply exclusively used for the electromagnetic brake. The electromagnetic
brake terminals (B1, B2) do not have polarity.
El
ec
tro
m
agnet
ic b
ra
ke
Switch
VAR
B1
U
B
24VDC power
supply for
electromagnetic
brake
B2
El
ec
trom
ag
ne
tic
b
ra
ke
Switch
VAR
B1
U
B
24VDC power
supply for
electromagnetic
brake
B2
or
A surge absorber (VAR) must be installed between B1 and B2. Refer to (3) in this section for the selection
method of surge absorber, and to "Electromagnetic brake characteristics" in section of each servo motor
series for selecting surge absorbers.
(2) Noise generation
Though the brake lining may rattle during operation in the low-speed area, it poses no functional problem.
If braking noise occurs, it may be improved by setting the machine resonance suppression filter or adaptive
vibration suppression control in the servo amplifier parameters. Refer to section 7.2 for details.
(3) Selection of surge absorbers for electromagnetic brake circuit
(a) Selection condition
Item
Conditions
24VDC
Varistor
Relay
Brake coil
U
Electromagnetic brake
specification
R[ ] : Resistance
L[H] : Inductance
Vb[V] : Power supply voltage
Desired suppressed
voltage
Vs[V] or less
Durable surge
application time
N times
Summary of Contents for MELSERVO-JN Series
Page 31: ... 22 MEMO ...
Page 49: ...2 6 2 INSTALLATION MEMO ...
Page 181: ...5 30 5 DISPLAY AND OPERATION SECTIONS MEMO ...
Page 199: ...6 18 6 GENERAL GAIN ADJUSTMENT MEMO ...
Page 303: ...11 46 11 OPTIONS AND PERIPHERAL EQUIPMENT MEMO ...
Page 351: ...12 48 12 SERVO MOTOR MEMO ...
Page 445: ...13 94 13 POSITIONING MODE MEMO ...