Lenze g500-H100, Project Planning

Page: 136 / 156

NOTICE
In case of travel axes, the compliance of the permissible ratio of mass inertia load/brake
motor (J
L
/J
MB
) ensures that the permissible maximum switching energy of the brake will not
be exceeded and at least the values given for the emergency stop functions from the given
speed (see rated data) are applied.
For hoist axes, the load torque resulting from the weight acts additionally. In this case, the
specifications for (J
L
/J
MB
) do not apply.
To simplify matters, the friction energy per switching cycle can be calculated using the formula
below and must not exceed the limit value for emergency stops, which depends on the
switching rate:
D æ ö
= ´ ´ p´ ´
ç ÷
-
è ø
2
N
ges
N L
M 1 n
Q J 2
2 60 M M
Q J Friction energy
J
total
kgm
2
Total mass inertia (motor + load)
Δn rpm Differential speed
M
N
Nm Rated torque of the brake
M
L
nM Load torque
The shortest operating times of the brakes are achieved by DC switching of the
voltage and an external suppressor circuit (varistor or spark suppressor).
Without suppressor circuit, the operating times may increase. A varistor/ spark
suppressor limits the breaking voltage peaks. It must be ensured that the power
limit of the suppressor circuit is not exceeded. This limit depends on the brake
current, brake voltage, disengagement time and the switching operations per
time unit.
Furthermore the suppressor circuit is necessary for interference suppression
and for increasing the service life of the relay contacts (external, is not
integrated into the motor).
It is not possible to readjust the brake.
Product extensions
Brakes
136