3--25
T-334
Table 3--7 Controller Pre-Trip Test Codes (Sheet 2 of 4)
P4-0
High Speed
Evaporator Fan
Motors On
Setup:
The High Speed Evaporator Fan is turned on, a current draw test is done
after 60 seconds.
Pass/Fail Criteria:
Passes if change in current draw is within the range speci-
fied. Fails if AL11 or AL12 activates during test for units operating with single fan
only.
P4-1
High Speed
Evaporator Fan
Motors Off
Setup:
The High Speed Evaporator Fan is turned off, a current draw test is done
after 10 seconds.
Pass/Fail Criteria:
Passes if change in current draw is within the range speci-
fied. Fails if AL11 or AL12 activates during test.
P5-0 Supply/Return Probe
Test
Setup:
The High Speed Evaporator Fan is turned on and run for eight minutes,
with all other outputs de-energized.
Pass/Fail Criteria:
A temperature comparison is made between the return and
supply probes.
NOTE
If this test fails, “P5-0” and “FAIL” will be displayed. If both Probe tests (this
test and the PRIMARY/ SECONDARY) pass, the display will read “P5”
“PASS.”
P5-1 Supply Probe Test
Requirements:
For units equipped with secondary supply probe only.
Pass/Fail Criteria
: The temperature difference between primary and secondary
probe (supply) is compared.
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 temperature difference between primary and secondary
probe (return) is compared.
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 is: 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 known position; Step 5: Open econ-
omizer 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
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
Alarm is activated if suction temperature is outside of the valid range of -60C
(-76F) to 150C (302F) 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.
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