Question:
In case of parallel operation of the 935X brake unit via the synchronisation interface the luminosity of the pilot lamp (LED) makes guess that the brake power is not distributed asymmetrically. Why?
Answer:
Via the synchronisation output A1/A2 the EMZ935X brake unit (brake chopper, brake module) gives a message when the switching transistor is enabled with raching of the selected threshold. If a brake unit is configured as 'Slave' (switch S3 = ON), the configured threshold (via S1 and S2) will be boosted by one voltage offset. A signal at E1/E2 makes sure that this offset is deactivated and that this brake unit activates the switching transistor dependent on the intermediate circuit voltage and the selected threshold.
The synchronisation interface distributes the brake power via brake units connected in parallel. Due to decelerations in the drive (approximately 10 µs per brake unit) the brake power is not distributed symmetrically, as each brake unit checks, if the switch on condition (intermediate circuit voltage > threshold) is valid.
Dependent on the brake unit and the storage capacity of the voltage link the time of switch on condition at the series-connected brake untis reduces, so that an increasing number of brake units leads to a reduced intensity of the yellow LED, this means a shorter breaking time.
As the LEDs require some time to intense their luminosity, there will be a deceleration in the display of the regenerative operation additionally to the above-mentioned operating behaviour.
