For controllers with a continuous output 0-10 Vdc.
For activating valves of the VZH-series with thread M30x1.5.
Existing systems can be upgraded with this drive by employing the adaptors.
Housing of fire-retardant plastic in pure white (as per RAL 9010); with integrated position indicator.
Fitted to the valve with bayonet ring M30×1.5 and bayonet nut.
Can be fitted in any position between the vertical and the horizontal.
White power cable (2 m in length on standard version, 4 × 0.25 mm2), fixed to the housing.
• Control signal 0-10 Vdc
• Power supply 24 V
• Stroke 4.5 mm standard, on request 3.0 mm
• Regulation 30 s/mm
• Spring force 125 N
• Direction of operation selectable via wiring
• Including adaptor M30x1.5 to suit VZH valves
• Length of cable 2 m
The actuator has an electrically heated, overload-proof expansion element which transfers its stroke direct to the valve. It works silently and requires no maintenance. When the heating element is switched on from cold, the valve (after a warming-up period of about 80 seconds) starts to open, reaching the maximum stroke of 4.5 mm after about 85 seconds. When the drive is regulating, a movement of 1 mm is carried out in about 30 seconds; the stroke is monitored by a Hall sensor. The closing operation is similar (with regard to time) to the opening operation: the expansion element cools down and the valve is closed by spring pressure.
Running time (warming-up)
From cold, the drive requires a warming-up period of approx. 80 seconds. A similar period is also needed if the drive is in the stand-by position for more than 6 minutes. The drive is then ready for control operations.
Running time (control)
When the drive is in control mode, the stroke of 4.5 mm is attained in approx. 85 seconds. A change of 1 mm in the stroke can be attained within 18 to 30 seconds. This tolerance depends on how long the drive stays in one position, before the positional change is ordered. Depending on the way it is wired up, the continuous drive can be used as 0-10 V (direction of operation 1) or 10-0 V (direction of operation 2). The output signal is then allocated linearly to this effective stroke.
The integrated positioner controls the drive as a function of positioning signal. The continuous drive positions the valve and the position is held as soon as it has been reached. The drive goes to stand-by mode as soon as the control voltage falls below 0.3V (in the case of direction of operation 1) or rises above 9.7 V (in the case of direction of operation 2). Afterwards, the dead time comes into effect before control can take place.
The starting point and the control span can be set via a potentiometer. This means that the controller’s control signal can be used to operate several regulating units in sequence or in cascade. The input signal (partial range) is amplified into an output signal of 0...10 V. This accessory cannot be fitted in the drive, but must be mounted externally in an electrical junction box. The drive can be ordered with an internal split-range function on request, in which case no accessories are needed.