Carrier 69NT20-531-300 manual Supply is compared, Test fails, P6-2, Crease, the test fails, P6-7

Table 3-7 Controller Pre-Trip Test Codes (Sheet 2 of 4)

		Requirements: For units equipped with secondary supply probe only.
		Pass/Fail Criteria: The temperature difference between primary and secondary probe
		(supply) is compared.
P5-1	Supply Probe Test	NOTE
		If this test fails, “P5-1” and FAIL will be displayed. If both Probe tests (this
		and the SUPPLY/ RETURN TEST) pass, because of the multiple tests, the
		display will read ’P 5’ ’PASS’.
		Requirements: For units equipped with secondary return probe only.
		Pass/Fail Criteria: The temperature difference between primary and secondary
		probe (return) is compared.
		NOTES
P5-2	Return Probe Test	1. If this test fails, “P5-2” and “FAIL” will be displayed. If both Probe tests
		(this test and the SUPPLY/ RETURN) pass, because of the multiple
		tests, the display will read “P 5,” “PASS.”
		2. The results of Pre-Trip tests 5-0, 5-1 and 5-2 will be used to activate or
		clear control probe alarms.
		Setup: The system is operated through a sequence of events to test the compo-
	Refrigerant Probes,	nents. The sequence is: Step 1, de-energize all outputs; Step 2, start unit with
P6	Compressor	unloader valve open. Open then close the suction modulation valve. Monitor
		suction pressure; Step 3, open suction modulation valve to a known position;
	and
		Step 4, close suction modulation valve to a know position; Step 5, open econo-
	Refrigeration valves
		mizer valve; Step 6, close unloader valve; Step 7, open unloader valve; Step 8,
		close economizer valve; Step 9, de-energize all outputs.
P6-0	Discharge	If alarm 64 is activated any time during the first 45 second period of Step 1, the
	Thermistor Test	test fails.
P6-1	Suction	If alarm 69 is activated any time during the first 45 second period of Step 1, the
	Thermistor Test	test fails.
P6-2	Discharge Pressure	If alarm 65 is activated any time during the first 45 second period of Step 1, the
	Sensor Test	test fails.
P6-3	Suction Pressure	If alarm 66 is activated any time during the first 45 second period of Step 1, the
	Sensor Test	test fails.
P6-4	Compressor Current	Compressor current is tested before and after start up. If current does not in-
	Draw Test	crease, the test fails.
P6-5	Suction Modulation	Suction pressure is measured before and after the valve opens. If suction pres-
	Valve Test	sure does not increase, the test fails.
P6-6	Economizer	Suction pressure is measured during Steps 4 and 5. If suction pressure does not
	Valve Test	increase, the test fails.
P6-7	Unloader Valve Test	Suction pressure is measured during Steps 6 and 7. If suction pressure does not
		increase, the test fails.

T-309 3-22