HORA MC55/24 - Three-Point Mode; Functions; Binary Signal; Frost Protection Function; Blockage Detection

2 Product Specification
Linear actuators MC100 • MC103
8 Version 2.1 - March 2011 Operating Manual
Input signal (Y) The input signal (Y) of the system control specifies the desired position for the
linear actuator. It is applied in the form of an analogue signal to terminal Y.
Possible input signals:
• 0 … 10 V DC / 2 … 10 V DC
• 0…20mA / 4…20mA
Output signal (X) The output signal (X) determines the actual position of the linear actuator. It is
applied to terminal X in the form of an analogue signal.
0% to 100% valve lift is put out as:
• 0…10VDC
• 0 … 20 mA or 4 … 20 mA (accessory PCB for output signal (111))
2.3.2 Three-point mode
The direction of rotation is set via the control voltage at terminal 2 and terminal 3
on the main PCB:
• When the control voltage is applied to terminal 2, the spindle nut will be
extended.
• When the control voltage is applied to terminal 3, the spindle nut will be
retracted.
2.4 Functions
2.4.1 Binary signal / frost protection function
The terminals B1 and B2 on the main PCB are bridged during normal operation.
If the electric circuit between B1 and B2 is interrupted, the linear actuator will store
the current position and afterwards move automatically to its limit position.
All other control signals will be ignored during this process.
The linear actuator will remain in limit position until the electric circuit between B1
and B2 has closed.
• In three-point mode the linear actuator will automatically return to the stored
position.
• In continuous mode the desired value of the input signal will be restarted.
2.4.2 Blockage detection
If the linear actuator is blocked manually, the linear actuator will briefly move back
and then retry to reach the required position. If this is still unsuccessful after a
total of 7 attempts the linear actuator will be turned off in order to prevent damage
to the linear actuator and the control element.
Blockage detection is indicated by LED
 6.2 LED display on page 30
2.4.3 Wire break detection
Wire break detection is only available for continuous mode with an input signal
2 … 10 V DC and 4 … 20 mA.
When the input signal drops below 1 V or 2 mA in continuous mode the linear
actuator will move to the limit position set by encoding switch S6.
Wire break detection is indicated by the LED.
 6.2 LED display on page 30