TEL AFA4000/E - Page 153

AFA4000/E VAV Airflow Controller / p.153
SW1
SW2
SW3
SW4
Mode
Range
• SW1 & SW2 are used to select the pressure range.
• SW3 is used to select Volume or Pressure output.
• SW4 is used to Tare (Zero) the pressure cell.
• The output proportional to pressure setting is used for testing purposes and not for
operational use (SW3 should be set to OFF).
8.5.3.1 Calibration (Tare)
1. With the cover on the enclosure, power up the Econ power supply and wait 5 minutes for
the pressure cell to stabilise.
2. Make sure the extract fan is switched off.
3. The LEDs will down the following:
Mode
Power
LED
Status LED
Fault LED
Vout1
Vout2
Sensor Fault
ON
OFF
ON
10V
10V
Requires Calibration
ON
FLASH
FLASH
10V
10V
Calibration in Progress
ON
FLASH
OFF
0V
0V
Warming up period
FLASH
OFF
OFF
0V
0V
OK
ON
ON
OFF
P/Vol OP
P/Vol OP
4. Set SW4 to the ON position, the Status LED will flash for 5 seconds whilst the cell output is
zeroed and the Fault LED will go solid.
5. Once the calibration is complete the Status LED will go solid.
6. Set SW4 to the OFF position.
7. The Power and Status LED's should be ON and the Fault LED should be OFF (OK).
Note: For best accuracy, the pressure cell calibration is required to compensate for altitude,
orientation of power supply box etc.
8.5.3.2 Testing
When the cell has been calibrated, and the extract fan is running, the measured volume will
display in the Diagnostics Menu I/O Status – Sensor Data screen (section 13.2).