Siemens SINAMICS V20 Operating Instructions Manual page 96

Commissioning via the built-in BOP
5.6 Function commissioning
Setting parameters
Parameter Function
P1236[0...2] Compound braking current [%]
P1254 Auto detect Vdc switch-on levels
Motor overheat
For compound braking, regenerative braking is superimposed on the DC braking (braking
along a ramp). This means that components of the kinetic energy of the motor and motor
load are converted into thermal energy in the motor. This can cause the motor to overheat if
this power loss is too high or if the brake operation takes too long!
Note
The compound braking depends on the DC link voltage only (see threshold in the above
diagram). This will happen on OFF1, OFF3 and any regenerative condition. Compound
braking is deactivated, if:
• flying start is active
• DC braking is active.
96
WARNING
Setting
This parameter defines DC level superimposed on AC wave-
form after exceeding DC-link voltage threshold of compound
braking. The value is entered in [%] relative to rated motor
current (P0305).
Range: 0 to 250 (factory default: 0)
This parameter enables / disables auto-detection of switch-on
levels for Vdc_max controller.
= 0: Disabled
= 1: Enabled (factory default)
It is recommended to set P1254 = 1 (auto detection of Vdc
switch-on levels enabled). Note that auto detection only works
when the inverter has been in standby for over 20s.
Operating Instructions, 11/2016, A5E34559884-006
SINAMICS V20 Inverter