Carrier 69NT20-531-300 Pressure switch is open or the condenser fan switch is open, Utes, P7-1

Table 3-7 Temperature Controller Pre-Trip Test Codes (Sheet 3 of 4)

NOTE

P7-0 through P10 are included with the “Auto2” only.

		NOTE
		This test is skipped if the sensed ambient temperature is less than 7_C
P7-0		(45_F), the return air temperature is less than -17.8_C (0_F), the water
	High Pressure	pressure switch is open or the condenser fan switch is open.
	Switch Closed
		Setup: With the unit running, the condenser fan is de-energized, and a 15 minute
		timer is started.
		Pass/Fail Criteria: The test fails if high pressure switch fails to open in 15 min-
		utes.
		Requirements: Test P7-0 must pass for this test to execute. Setup: The con-
P7-1	High Pressure	denser fan is started and a 60 second timer is started.
	Switch Open	Pass/Fail Criteria: Passes the test if the high pressure switch (HPS) closes
		within the 60 second time limit, otherwise, it fails.
		Setup: If the container temperature is below 15.6°C (60_F), the set point is
		changed to 15.6°C, and a 180 minute timer is started. The left display will read
P8-0	Perishable Mode	“P8-0.” The control will then heat the container until 15.6°C is reached. If the
		container temperature is above 15.6°C at the start of the test, then the test pro-
	Heat Test
		ceeds immediately to test P8-1 and the left display will change to “P8-1.”
		Pass/Fail Criteria: The test fails if the 180 minute timer expires before the con-
		trol temperature reaches set point. The display will read “P8-0,” “FAIL.”
		Requirements: Control temperature must be at least 15.6°C (60_F).
		Setup: The set point is changed to 0°C (32_F), and a 180 minute timer is
P8-1	Perishable Mode	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
	Pull Down Test
		set point.
		Pass/Fail Criteria: The test passes if the container temperature reaches set point
		before the 180 minute timer expires.
		Requirements: Test P8-1 must pass for this test to execute. This test is skipped
		if the DATAcorder is not configured or available.
		Setup: The left display will read “P8-2,” and the right display will show the sup-
		ply air temperature. A two hour timer is started. The unit will be required to
		maintain the temperature to within + or - 0.5_C (0.9_F) of set point until a Da-
		taCORDER recording is executed. The recorder supply probe temperature run-
	Perishable Mode	ning total (and its associated readings counter) will be zeroed out for the remain-
		der of the recording period at the start of this test, so that the actual value
P8-2	Maintain Tempera-
		recorded in the DataCORDER will be an average of only this test’s results. Once
	ture Test
		a recording interval is complete, the average recorder supply temperature will be
		recorded in the DataCORDER, as well as stored in memory for use in applying
		the test pass/fail criteria.
		Pass/Fail Criteria: If the recorded temperature is within +/- 0.5_C. of set point
		from test start to DataCORDER recording, the test passes. If the average temper-
		ature is outside of the tolerance range at the recording, the test fails and will
		auto-repeat by starting P8-0 over.
		Setup: The defrost temperature sensor (DTS) reading will be displayed on the
		left display. The right display will show the supply air temperature. The unit will
		run FULL COOL for 30 minutes maximum until the DTT is considered closed.
P9-0	Defrost Test	Once the DTT is considered closed, the unit simulates defrost by running the
		heaters for up to two hours, or until the DTT is considered open.
		Pass/Fail Criteria: The test fails if: the DTT is not considered closed after the
		30 minutes of full cooling, HTT opens when DTT is considered closed or if re-
		turn air temperature rises above 49/50_C (120/122_F).

3-23 T-309