Lenze ERBSxxxxxxxx - Manual (Page 40)

3 Product description
Dimensioning conditions
EDKRBS047R DE/EN/FR/ES/IT 8.0
40
l
−H1−Auslegungsbed_Bremswiderst_Bsp
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
Examples of the evaluation of the condition
The brake resistor cycle t
cyc,RB
= 150 s and the max. total braking time t
brk,max
= 10 s are
given. The braking times t
brk
and the process cycle t
cyc,Prc
are exemplary.