Master switch signals

The incoming signals from the master switch, such as setpoint and control enable, are loaded.

• A master switch with setpoint potentiometer can be connected direct to the SIMOTRAS HD.
• A 4‑stage master switch requires the CUD2 terminal expansion module for connection.

Ramp-function generator

The series-connected ramp-function generator with adjustable ramps forms the speed setpoint.

Speed controller

The speed controller with the subordinate current control circuit is connected down-circuit of the ramp-function generator and forms the actual control loop.

Start pulse

A start pulse is also generated so that the machine is activated in the hoisting direction of rotation immediately after power up. This prevents the load from dropping on start-up.

Sequencer

For switching through the rotor stages, a sequencer is installed that selects the planned stages speed-dependently and activates reversing.

Standstill monitoring

The integral zero-speed monitoring supports guided, electrical braking of the drive. For replacing the cable, e.g. in hoists, jog mode with creep speed is provided.

Operating states

The operating states are indicated in the device on a 5-digit, 7-segment display as well as the LEDs of the basic PMU operator panel.

Operating modes

The threshold for switchover between closed-loop and open-loop controlled operation can be defined in accordance with the control characteristic and set on the parameters of the device.

Parallel connection

To increase the performance, up to 6 devices can be connected in parallel. The terminal expansion option (CUD2) is required in this case for every device and (n-1) patch cable. Current splitting requires identical, separate parallel switching reactors for each SIMOTRAS device. The difference in reactor tolerances determines the current distribution. For operation without derating (current reduction), a tolerance of 5 % or better is recommended. Only devices with the same current ratings are permitted to be connected in parallel.