P8 Tests - Perishable Mode Tests: Pretrip tests P7-0 and P7-1 must have passed or have been skipped for these tests to execute.
| P8-1 Perishable Mode Pull Down Test / eAutofresh CO2 Sensor Calibration |
| Control temperature must be at least 15.6 C (60 F). The set point is changed to 0 C (32 F), and a 180-minute timer is started. The left display will read “P8-1,” the right display will show the supply air temperature. The unit will then start to pull down the temperature to the 0 C set point. The test passes if the container temperature reaches set point before the 180-minute timer expires. On units where the CO2 Sensor Status indicates that a CO2 sensor is present, calibration of the CO2 sensor will be attempted during P8-1. Once P8-1 begins, calibration will be attempted when the supply temperature goes below 5 C. If the CO2 sensor voltage reads within the 0.95 <>1.15Vdc range before the end of P8-1, the sensor will be calibrated by holding the CO2 zero line low for 4 seconds. Once calibration is performed, the sensor voltage will be verified to make sure it is in the 0.95 to 1.05 Vdc range. If the voltage is not within this range, CO2 sensor calibration fails. |
