MGM
39
BM series brake group
BM series brake motors can be connected as diagram A or B according to the needed braking time. MGM motors are always provided
with DC brake coil connected as diagram A. The DC brake coil has to be connected according to diagram B in order to have a quicker
brake action. Here below brake intervention times and brake release time are provided.
T
b
0,9 M
bn
t
T
bn
t
1
0,1 M
bn
t
21
t
22
t
2
T
b
Brake Torque
T
bn
Nominal Brake Torque
t
1
Switch-on time
t
21
Delay Time
t
22
Rise Time
t
2
Reaction Time
The chart here below describes the trend of the braking torque as a function of time, during the start (on the left) and stop (on the
right). The table below also show times for each type of motor and the values of Er (MJ) to calculate the number of braking actions
between two consecutive air gap adjustments. (See page 33).
Frame size
t
22
quick
(ms)
t
2
quick
(ms)
t
21
standard
(ms)
t
22
standard
(ms)
t
2
standard
(ms)
t
1
(ms)
t
21
quick
(ms)
E
rBM
(MJ)
Rectifiers wiring diagram
Braking Time
BM series
Brake coil
Black
Grey or Brown
Red
White
White
Brake coil
Black
Grey or Brown
Red
White
White
Diagram A
Diagram B
*Note: The air gap can’t be restored on BM56 motors. The brake disc have to be replaced when the air gap exceed the stated value.
The braking time t
f
(s) can be calculated as follows:
t
f
=
J
tot •
n
9.55 (T
b
±
T
load)
+
1000
t
2
Where: J
tot
total moment of inertia at the motor shaft (Kgm
2
)
n
motor RPM (min
-1
)
T
b
brake torque (Nm)
T
load
resisting load torque (Nm) with + sign if matches the brake torque, or – sign if opposite
t
2
brake electrical reaction time (ms)
This calculation gives an approximative indication. Please contact MGM staff for more information.
56
63
71
80
90
100
112
132
160
30
35
35
45
60
80
120
160
200
10
10
10
15
20
25
30
40
50
15
15
15
30
40
50
60
80
100
25
25
25
45
60
75
90
120
150
35
40
40
50
80
100
120
160
200
25
30
30
45
60
75
90
120
150
60
70
70
95
140
175
210
280
350
7*
15
15
23
29
33
36
39
44