Table of Contents
This feature was added to Tracer TU starting in Version 12
Use the Calibrate ECM dialog box to drive the fan to maximum and minimum speeds so you can take physical air flow measurements. Tracer TU uses your measured values to calculate and set the necessary data points that affect maximum and minimum fan speeds. This dialog is available on all versions of WSHP equipment with staged compressors and an ECM fan. This dialog is also available on WSHP equipment with a variable speed compressor and a Mitsubishi variable frequency drive.
Access
Select the Flow Calibration tab and then open the Actions expanding box.
Dialog Box Content
(1) Current Operating Status – This section displays values at the time the dialog box is opened. It then provides continuously updated values for these points reflecting the active status.
(2) Fan Speed Override Status – This value displays the override status of the ECM fan. To maintain consistency with other equipment with ECM fans, the values displayed here will be “Auto” if no override is present and “High Speed”, “Low Speed”, “Medium Speed”, or “Off” if associated overrides are present.
(3) Current Fan Speed Output – This value displays the active speed status of the ECM fan in percent.
(4) Set Maximum Fan Speed – This section displays values and actions necessary for setting maximum fan speed to provide design maximum air flow.
(5) Override Fan High Speed – This button places a temporary (4 hour) override on the ECM fan, driving it to high speed. The override status should be reflected in the Current Operating Status section. After allowing some time for the fan to reach operating speed, physical air flow measurements can be taken.
(6) Actual Air Flow % – This field expects a value between 1 and 200 percent. To calculate the value to enter, divide your measured air flow value by the design maximum air flow and multiply the result by 100. For example, if your measured air flow is 994 cfm and the design maximum air flow is 1000 cfm, you would enter 99.4 (994 / 1000 * 100) into this field.
(7) Calculate – This button calculates the correct data point values to adjust the ECM fan maximum speed based on the entered Actual Air Flow %. It will be enabled after a valid value is entered into the Actual Air Flow % field. A temporary (4 hour) override will be placed on these points so further measurements can be taken if desired before setting them permanently by clicking the Apply or Done button. This temporary override also allows you to cancel any changes you’ve made so far by clicking the Cancel button.
(8) Set Minimum Fan Speed – This section displays values and actions necessary for setting minimum fan speed to provide design minimum air flow.
(9) Override Fan Low Speed – This button places a temporary (4 hour) override on the ECM fan, driving it to low speed. The override status should be reflected in the Current Operating Status section. After allowing some time for the fan to reach operating speed, physical air flow measurements can be taken.
(10) Actual Air Flow % – This field expects a value between 1 and 200 percent. To calculate the value to enter, divide your measured air flow value by the design minimum air flow and multiply the result by 100. For example, if your measured air flow is 197 cfm and the design minimum air flow is 200 cfm, you would enter 98.5 (197 / 200 * 100) into this field.
(11) Calculate – This button calculates the correct data point values to adjust the ECM fan minimum speed based on the entered Actual Air Flow %. It will be enabled after a valid value is entered into the Actual Air Flow % field. A temporary (4 hour) override will be placed on these points so further measurements can be taken if desired before setting them permanently by clicking the Apply or Done button. This temporary override also allows you to cancel any changes you’ve made so far by clicking the Cancel button.
(12) Calculation Results – This section displays values affected by any calculation performed. WSHP equipment with staged compressors will display Supply Fan Maximum Heat Cool Capacity, Supply Fan Speed Ventilation, Supply Fan Speed First Stage Minimum, and Supply Fan Speed Dehumidification data point values. WSHP equipment with a variable speed compressor will display Supply Fan Maximum Heat Cool Capacity and Supply Fan Speed Ventilation data point values. These values are continuously updated for these points reflecting the active status.
(13) Done – This button sets the default values for all data points necessary for ECM fan speed calibration, releases all overrides made during the calibration process, returns the equipment to normal operation, and closes the dialog box. It is enabled after either Calculate button is clicked.
(14) Cancel – If you have made any changes in the controller without clicking Apply, this button allows you to cancel any changes you’ve made so far and close the dialog. Clicking Cancel in this scenario will bring up a Save? dialog that allows you to save your changes and exit, to exit without saving, or to return to the main dialog.
(15) Apply – This button sets the default values for all data points necessary for ECM fan speed calibration, releases all overrides made during the calibration process, and returns the equipment to normal operation. The dialog box will remain open to allow you to complete further calibration, if desired. It is enabled after either Calculate button is clicked.