Carrier 69NT20-531-300 Refrigerator User Manual


 
3-22T -309
Table 3-7 Controller Pre-Trip Test Codes (Sheet 2 of 4)
P5-1 Supply Probe Test
Requirements: For units equipped with secondary supply probe only.
Pass/Fail Criteria : The temper atur e diffe re nc e betwe en pr imar y and sec onda ry probe
(supply) is compa re d.
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’.
P5-2 Return Probe Test
Requirements: For units equipped with secondary return probe only.
Pass/Fail Criteria: The temper atur e dif f er enc e betwe en pr imary a nd seconda ry
probe (r etur n) is compar ed.
NOTES
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.
P6
Refrigerant Probes,
Compressor
and
Refrigeration valves
Setup: The system is operated through a sequence of events to test the compo-
nents. The sequence i s: Step 1, de--energize all outputs; Step 2, start unit with
unloader valve open. Open then close the suction modulation valve. Monitor
suction pressure; Step 3, open suction modulation valve to a known position;
Step 4, close suction modulation valve to a know position; Step 5, open econo-
mizer valve; Step 6, close unloader valve; Step 7, open unloader valve; Step 8,
close economizer valve; Step 9, de--en ergize all outputs.
P6-0
Discharge
Thermistor Test
If alarm 64 is activated any time during the first 45 second period of Step 1, the
test fails.
P6-1
Suction
Thermistor Test
If alarm 69 is activated any time during the first 45 second period of Step 1, the
test fails.
P6-2
Discharge Pressure
Sensor Test
If alarm 65 is activated any time during the first 45 second period of Step 1, the
test fails.
P6-3
Suction Pressure
Sensor Test
If alarm 66 is activated any time during the first 45 second period of Step 1, the
test fails.
P6-4
Compressor Current
Draw Test
Compressor current is tested before and after start up. If current does not in-
crease, the test fails.
P6-5
Suction Modulation
Valve Test
Suction pressure is measured before and after the valve opens. If suction pres-
sure does not increase, the test fails.
P6-6
Economizer
Valve Test
Suction pressure is measured during Steps 4 and 5. If suction pressure does not
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.