Operating instructions FS-26E
Status as of 10 / 2019
Page 7
2 Application
The electronic frequency converter FS 26 is used for the infinitely variable control of inductive loads,
such as spiral conveyors, linear conveyors and hoppers.
The device works according to the principle of pulse width modulation within the half-waves with
adjustable periods of 5 - 200 Hz; the conveying capacity is adjusted by adjusting the magnet voltage via
the membrane keypad embedded in the housing cover or alternatively selectable via 0-10 V DC, 4-
20 mA or an external 10 kOhm potentiometer in the range of 1V~ up to the maximum output voltage. By
limiting the upper and lower setpoint limits, the optimal specified range can be moved along via the
setpoint.
The amplitude of the sinusoidal output current (upper half-wave) depends on the set period and is
therefore constant. The vibration frequency is set via the keypad as standard.
After switching on the mains voltage, the integrated, adjustable soft start is started and ensures the
output voltage starts up jerk-free up to the set voltage value. A limiter stage limits the load current of the
capacitors to 6 A in the moment of switch-on. Possible switch-on peaks are minimized this way.
Furthermore, both the soft start as well as the soft stop when the output voltage is switched on/off are
activated via the control input and are for increasing and decreasing the conveying capacity with time
control so that ordered bulk material does not change its position again. Both times can be adjusted
separately.
The control inputs allow the device to be switched on and off by another system (PLC, initiator, sensors,
etc.). The control device therefore provides its own supply voltage of +24 V DC. Switching on or off via an
external voltage of + 24 V DC is also possible.
Via the additionally integrated outputs, external devices can be operated or controlled, depending on the
logic specification.
The device provides an input for connecting an acceleration sensor for readjusting the output voltage.
Note
By determining the mains voltage and output current, changes are registered immediately and
compensated for by a controller stage, i.e. the output voltage remains stable. This way, the bulk
material is guaranteed to run smoothly.
Tip
On the control device, small magnets can also be safely operated.
