3--26
T-334
Table 3--7 Temperature Controller Pre-Trip Test Codes (Sheet 3 of 4)
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.
P7-0 High Pressure
Switch Open
NOTE
This test is skipped if the sensed ambient temperature is less than 7C (45F),
the return air temperature is less than 17.8C (0F), the water pressure switch
is open or the condenser fan switch is open.
NOTE
P7-0 & P8 are included with “Auto2 & Auto 3” only. P9-0 through P10 are included with “Auto2” only.
P7-0 High Pressure
Switch Open
Setup:
With the unit running, the condenser fan is de-energized, and a 15 min-
ute timer is started.
Pass/Fail Criteria:
The test passes if high pressure switch opens any time after
the compressor starts. Test fails if: High pressure switch fails to open within
15 minutes; AL 22 or AL 24 are activated; water pressure switch opens; dome
temperature is higher than 140.56C (285.01F); discharge pressure is greater
than 370 psig; discharge pressure and calculated dome temperature become
invalid; compressor current is greater than 125% of current limit calculated from
input voltage and frequency.
P7-1 High Pressure
Switch Closed
Requirements:
Test P7-0 must pass for this test to execute. Setup: The con-
denser fan is started and a 60 second timer is started.
Pass/Fail Criteria:
Passes the test if the high pressure switch (HPS) closes
within the 60 second time limit, otherwise, it fails.
P8-0 Perishable Mode
Heat Test
Setup:
If the container temperature is below 15.6C (60F), the set point is
changed to 15.6C, and a 180 minute timer is started. The left display will read
“P8-0.” The control will then heat the container until 15.6C is reached. If the con-
tainer temperature is above 15.6C at the start of the test, then the test proceeds
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.”
P8-1 Perishable Mode
Pulldown Test
Requirements:
Control temperature must be at least 15.6C (60F).
Setup:
The set point is changed to 0C (32F), and a 180 minute timer is started.
The left display will read “P8-1,” the right display will show the supply air temper-
ature. The unit will then start to pull down the temperature to the 0C set point.
Pass/Fail Criteria:
The test passes if the container temperature reaches set
point before the 180 minute timer expires.
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