Specifications

9.CHARACTERISTICS
9– 8
Emergency stop
Brake current
Machine speed
V0
t1 t2 t3
(2) Electromagnetic brake power supply
24VDC of the internal power output for interface (VDD) cannot be used. Prepare the following
power supply for use with the electromagnetic brake only.Examples of connection of the brake
exciting power supply are shown in Fig. 9-3 (a) to (c). (a) is for AC off, and (b) and (c) for DC
off. When DC is switched off, the braking delay time will be shortened, but a surge absorber
must be installed on the brake terminal. For the selection of the surge absorber, refer to Sec-
tion 6-2-5.
T : Transformer
RF : Rectifier
VAR : Surge absorber
(3) Coasting distance
At an emergency stop, the servo motor will decelerate to a stop in the pattern shown in Fig. 9-
4. Here, the maximum coasting distance (during fast feed), Lmax, will be the area shown with
the diagonal line in the figure and can be calculated approximately with Equation 9-2. The
effect of the load torque is greater near the stopping area. When the load torque is large, the
servo motor will stop faster than the value obtained in the equation.
28V AC
Switch
RF
(a)
T
Electromagnetic
brake
100V AC
or
200V AC
RF
(b)
T
Switch
VAR
100V AC
or
200V AC
Electromagnetic
brake
(c)
Switch
VAR
24V DC
Electromagnetic
brake
Fig. 9-2 Connection Examples
Fig. 9-3 Coasting Distance at Emergency Stop