Siemens SINAMICS V20 Series - Page 74

Commissioning
5.6 Function commissioning
SINAMICS V20 Inverter
74 Operating Instructions, 07/2012, A5E03728167
The continuous power P
DB
and the duty cycle for the braking resistor can be modified using
the dynamic braking module (for frame size A / B / C) or parameter P1237 (for frame size D).
WARNING
The average power of the braking chopper cannot exceed the power rating of the braking
resistor.
t
t
P
DB
P
100
t
ON
t
OFF
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Duty cycle t
ON
(s) t
OFF
(s) t
cycle
(s) P
DB
5% 12.0 228.0 240.0 0.05
10% 12.6 114.0 126.6 0.10
20% 14.2 57.0 71.2 0.20
50% 22.8 22.8 45.6 0.50
100% Infinite 0 Infinite 1.00
Setting parameters
Parameter Function Setting
P1237 Dynamic braking This parameter defines the rated duty cycle of the braking
resistor (chopper resistor). Dynamic braking is active when
the function is enabled and DC-link voltage exceeds the
dynamic braking switch-on level.
= 0: Disabled (factory default)
= 1: 5% duty cycle
= 2: 10% duty cycle
= 3: 20% duty cycle
= 4: 50% duty cycle
= 5: 100% duty cycle
Note: This parameter is only applicable for inverters of frame
size D. For frame sizes A to C, the duty cycle of the braking
resistor can be selected with the dynamic braking module.
P1240[0...2] Configuration of Vdc controller This parameter enables / disables Vdc controller.
= 0: Vdc controller disabled
Note: This parameter must be set to 0 (Vdc controller
disabled) to activate the dynamic braking.