XF0

A static differential pressure transducer converts the differential pressure into a voltage signal. The differential pressure actual value is available as a voltage signal. The factory setting is such that 10 V DC always corresponds to the nominal differential pressure (Δ_{p nom}). The differential pressure setpoint value is either a constant value or it comes from a setpoint adjuster or from switch contacts. The controller compares the differential pressure setpoint value to the actual value and controls the actuator accordingly if there is a difference. Differential pressure parameters and signal voltage range are stored in the control component. Customers can easily make changes using an adjustment device or a notebook with service tool.

Compact controllers for VAV terminal units

Compact controller XF0, 227P-024-15-DS6

Analogue interface 0 – 10 V or 2 – 10 V DC (operating mode V, F)

The analogue interface can be set for signal voltage range 0 – 10 V DC or 2 – 10 V DC. The assignment of the duct pressure setpoint value or actual value to a voltage signal is shown in the characteristic curves.

▪ The set signal voltage range applies to both setpoint value and actual value signals

▪ The signal voltage range is pre-set in the factory in accordance with the order code entries

▪ The signal voltage range can be adjusted by others with an adjustment device

Setpoint value default setting

Variable operation

▪ In operating mode V (variable operation), the setpoint comes from an analogue signal on terminal Y

▪ The selected signal voltage range 0 – 10V or 2 – 10V DC is assigned to the pressure range Pmin – Pmax .

▪ Operating values Pmin – Pmax preset at the factory according to the order code

▪ Subsequent adjustment of Pmin or Pmax is possible with adjustment device

Constant value mode

▪ In the operating mode F (constant value mode), an analogue signal is not required on terminal Y

▪ The set duct pressure constant value Pmin is used.

▪ Operating value Pmin is preset at the factory according to the order code

▪ Subsequent adjustment of Pmin is possible with adjustment device

Actual value as feedback for monitoring or tracking control

▪ The actual duct pressure measured by the controller can be captured as a voltage signal at terminal U

▪ The selected signal voltage range 0 – 10V DC or 2 – 10V DC is converted to the pressure range 0 – PNominal .

▪ Reference point PNominal = 600 Pa

Override control

For special operating situations, the duct pressure controller can be put in a special operating mode (override control). The following modes are possible: control Pmin, control Pmax, damper blade in the OPEN position, damper blade CLOSED. Under certain conditions, the control can also be suspended (control stop).

Override control via signal input Y

With appropriate wiring on the signal input Y, the override controls can be activated according to the connection diagrams via wiring with external switch contacts/relays. OPEN and CLOSED are only available if the controller is supplied with alternating current (AC). In the signal voltage range 2 – 10 V, the differential pressure control can be suspended (stop) by connecting input Y to GND.

Override control CLOSED via control signal Y

• With signal voltage range 0 – 10 V DC: CLOSED is activated when Pmin = 0 is set and control signal Y < 0.5 V DC
  
  
• With signal voltage range 2 – 10V DC: CLOSED is activated when control signal is Y < 0.8V (*1) DC (*1) 0.8V = factory setting

Override control for diagnostic purposes

• For test purposes, the override control can also be activated via the service tools (adjustment device, PC software).

Prioritisation of various setting options

• High priority: settings via the service connector (adjustment device, PC software) for test purposes
• Low priority: settings via Y signal input of the controller

Commissioning

• On-site adjusting is not required
  
  
• Due to the duct pressures set in the factory, always ensure that the control units are only installed in the specified locations
  
  
• Install control unit in the duct section to be controlled
  
  
• Set up a pressure measurement point

For supply air:

• Connect the positive connection point of the controller to the duct to be controlled
  
  
• Leave the negative connection point of the controller open

For extract air:

• Leave the positive connection point of the controller open
  
  
• Connect the negative connection point of the controller to the duct to be controlled
  
  
• The duct connection has to be on the side facing away from the fan
  
  
• Note duct pressure control ranges as per technical data
  
  
• Establish electrical wiring connection
  
  
• The controller is then ready for use