Activation and deactivation - Basic Documentation - GDB181.1E/BA - GDB181.1EMBA - GLB181.1E/BA

VAV Compact Controller BACnet MS/TP G..B181.1E/BA

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Damper actuators
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Technical Documentation > Basic Documentation
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  • Immediately after changing the parameter “Adaptive positioning” from off to on, an adaptation run is performed. During the adaptation run, the actuator drives to both mechanical end stops and stores these positions persistently as 0% and 100% reference points. See the diagram below for a detailed description.

    Important: Adaptation must not be activated while a device jam is present!

  • Adaptive positioning can be (de-)activated with the service interface (ACS931 / ACS941 / AST20) or over the bus.

  • If adaptive positioning is deactivated before the adaptation run has finished, the adaptation run will stop immediately, and no end stops will be stored.

  • In case of a power reset during the adaptation run, the adaptation run will restart automatically after the power supply has been restored.

  • To trigger the adaptation run again the adaptive positioning must be turned off and on again.

  • A manual gear disengagement of less than 20 seconds doesn’t impact the adaptation run or its result.

  1. Adaptive positioning is set to on. Actuator drives to the counter-clockwise (CCW) endstop.

  2. CCW endstop is reached.

  3. If the position remains constant for ca. 10 seconds, it is stored non-volatile. The actuator then drives to the clockwise (CW) endstop.

  4. CW endstop is reached.

  5. If the position remains constant for ca. 10 seconds, it is stored non-volatile. The actuator now follows the adapted setpoint.

Example: Stop screw set at ~75% of the full range
Note: If the adaptation run starts close to the CW endstop, it can take up to 5.5 minutes for completion (2x 150s + waiting times in the endstops).
  1. Device Jam

  • If an actuator can’t reach a target position due to a mechanical failure or an angle limitation screw, a device jam alarm is thrown.

  • The device jam is detected ca. 30s after the effective mechanical end stop (when lying before the target end stop) is reached.

  • After 30..35s the motor stops and the steady red LED indicates the device jam alarm until the blockage is physically removed.

  • Initiating an adaptation run while the actuator is jammed does not resolve the alarm by using the mechanical end stop as reference position.

    1. Operating mode

The operating mode determines whether the setpoint signal (0…100 %) from the supervisory controller is interpreted as volume flow control or as (air damper) position control.

If used as damper control signal, the actual values from the flow sensor remain available. This allows to implement the flow control loop in an external controller.

  1. Backup mode

In case the communication to the controller is lost, the device can be configured to go into a defined state. This function utilizes a watchdog which monitors setpoint write access over the bus.

Default setting of this backup mode is “Off”, i.e. in case of a communication loss, the device controls to the last received setpoint until an updated setpoint is received.

If the backup mode is enabled, it can be configured as follows:

  • go to a position predefined by the parameter “Backup position”,

  • keep current position without controlling to the last received setpoint.

When the device is in backup mode and receives a setpoint over the bus again, it wakes up and controls to the setpoint again.

  1. Restarting the device

    Restarting is possible by:

  • Power-reset (switching operating voltage off and on) or

  • by “ReInitDevice” command.

    Effect of restart: Device re-initializes and sets all process values to defaults.

    1. Reset behavior

The actuator supports the following re-initialization / reset behavior:

  • Local reset by push-button: cf. section 0

  • Tool-reset, cf. section 5.2

  • Remote reset: Using “RemoteFactoryReset” command.

    Effect of reset:

  • Process values: set to ex-works default values.

  • Parameters:

    • Application and actuator parameters are set to factory or OEM defaults,

    • Network parameters are reset only in case of local reset, not by remote reset (otherwise loss of communication).

  • Counters are not reset.

  • Status flags are not reset.

  • Device Information and Factory Data are not reset.

    1. Self-test

The actuator supports a self-test. When triggered, the self-test runs the actuator to the detected limits and sets the flags according to the result (cf. properties “Actuator Command” and “Self-test Status”).

  • The self-test is not passed when the lmits were not reached from the lower end (results in device jam).

  • If the limits can be exceeded, the self-test is not evaluated as failed.

    1. Configuration check

The actuator supports a basic configuration check for the relation between Vmin and Vmax: Vmax must be greater then Vmin, otherwise this is regarded an invalid configuration. Tolerance level is 2% difference.

In case of an invalid configuration, the LED blinks red and the flag “invalid configuration” in the according BACnet property (cf. 9.2.5) is set to “1”.