Question:
Do the brake units 9350 (brake module 9351, brake chopper 9352) in 'Slave' mode (S3=ON) also work without a control signal from the master at the input E1/E2 ?
Answer:
The 'Slave' setting (S3 = ON) is only designed for the synchronised master/slave operation of several brake choppers operated in parallel (application as directed). The master activates the brake function of the slaves via the inputs E1/E2.
The 'Slave' mode setting (S3 = ON) is not designed for only one brake unit.
Under certain circumstances and rather accidentally it may happen that the brake unit will also work without a control signal from the master because in the slave mode the brake function can, in parallel to the activation via the inputs E1/E2 also be activated depending on the height of the DC-bus voltage applied. In the slave mode, the switching thresholds are, however, much higher than in the default 'Master' setting (S3 = OFF). Moreover, the higher switching thresholds in the slave mode are subject to high tolerances (see below) so that the actual switching thresholds may also be above the overvoltage thresholds (OU) of the controllers and the brake unit thus can no longer become active in time before the controllers are inhibited.
This is why operation in 'Slave' mode without control signal from the master is not recommended and is not provided for by Lenze either.
Switching thresholds:
Master (S3 = OFF):
S3 S2 S1 Mains Switching threshold ON OFF
OFF OFF OFF 230 V 375 V 369..383 V 361..375 V
OFF OFF On 400..460 V 725 V 715..742 V 700..725 V
OFF On OFF --- approx. 407 V (setting is not designed for use)
OFF On On 480 V 765 V 751..778 V 736..762 V (default setting)
Slave (S3=ON):
S3 S2 S1 Mains Switching threshold
On OFF OFF 230 V 398 V (+/-5 %)
On OFF On 400..460 V 768 V (+/-5 %)
On On OFF --- ---
On On On 480 V 806 V (+/-5 %)
