Dimensioning conditions, Product description – Lenze ERBDxxxRxxxx User Manual
Page 42
Product description
Dimensioning conditions
l
42
EDKRBD180R DE/EN/FR 7.0
3.4
Dimensioning conditions
If brake resistors are used, observe the following:
ƒ
Mean value of regenerative power < permanent power P
d
of the brake
resistor.
ƒ
Regenerative power during braking time < heat quantity Q
B
of the brake
resistor.
ƒ
Braking time < 10 % of cycle time (braking time + dead time).
ƒ
Always connect the thermal contact and integrate it in a way into the
system monitoring that the mains supply will be switched off when the
standard device is overheated.
At all times, the following must apply: In the time interval t
cyc,RB
(brake resistor
cycle) the cumulative braking times t
brk
must always be
£
of the maximum total
braking time t
brk,max
.
Calculation
Brake resistor cycle t
cyc,RB
:
t
cyc,RB
+ Q
B
P
d
with
Q
B
Heat quantity in Ws
P
d
Permanent power in W
Max. total braking time t
brk,max
within the time interval t
cyc,RB
:
t
brk,max
+ Q
B
@ R
B
U
max
2
with
Q
B
Heat quantity in Ws
R
B
Resistance in
W
U
max
Max. operating voltage in V