Equipment Control

Configuring Unit Ventilator Equipment Control

Use the Unit Ventilator Equipment Control page to select cascade control options, fan, and smoke control options.

Purpose

Define Equipment Control parameters that the Excel 10 Controller uses to control the unitary equipment.

Mode

Off-line or On-line

Procedure

  1. Click the EquipmentControl button on the left pane to open the Equipment Control Configuration page.
  2. Enter information into available fields.
  3. Click Commit to save the settings or Reset to revert to the last saved settings.
  4. Click Next to display the Economizer Configuration page or Back to display the Input Configuration page.

Fields

Name Definition
Cascade Control Cascade control modulates/stages heating/cooling to control discharge air temperature, and uses space temperature to reset the discharge air temperature set point. Select one of the following cascade control options:
  • Yes - Select Yes only if 1both a Discharge Air Temperature sensor and modulating heating or cooling are configured.
  • No - Select No if the heating/cooling equipment are controlled strictly from space temperature, and discharge temperature is not used.
Fan Control Select one of the following fan control options:
  • Auto - Auto cycles the fan with call for cooling (and heating if you set Fan - Heating to On [next parameter]).
  • Continuous - Continuous means the fan runs continuously in the Occupied mode, and intermittently (with call for heating/cooling) in the Unoccupied mode
Fan Run on Heat Select one of the following fan control options:
  • On
  • Off - Select Off to allow for control circuits where, when in heat mode, the fan is directly controlled by an interlock control circuit (not part of the Excel 10 controller) which brings on the fan once the plenum temperature has risen above its thermostatic set point.
Smoke Control This value determines what the controller does when a smoke alarm occurs (either from the digital input, or via the LonWorks Bus network). Select one of the following smoke control options:
  • Fan Off Damper Closed
  • Fan On Damper Open
  • Fan On Damper Closed
Fan Fail Time This option is enabled if an Air Flow switch was selected. This value sets the amount of time that must pass after closed contacts on the Air Flow switch are detected before the controller shuts down and attempts a restart.

If three fan start attempts fail to prove air flow, the controller is disabled and locked out until reset. This action allows the fan to come up to speed on start up, and prevents false air flow failure alarms.
Filter Setpoint This option is enabled if an analog Filter Pressure sensor was selected. If the measured pressure exceeds this setpoint, the Dirty Filter alarm is issued. There is a built-in hysteresis of 25 percent of the Filter Press Stpt value (for the Dirty Filter alarm to return to normal).

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