Carrier 69NT40-489-100 Series Operation And Service Manual page 132

display. If pre-trip was not executed since power up,
then the right display will display "Auto". The user may
scroll through the test selection menu using the
ARROW keys.
A given test is selected by pressing ENTER while it is
displayed. The entire battery of tests may be run by
pressing ENTER while "Auto" is displayed.
During this selection mode, failure to press either an
ARROW key or ENTER for five seconds will return the
system to its default display and normal operating
mode.
Once a test has been selected, the message "CLOSE
DOOR" will be displayed. The user then has up to 15
minutes to make sure the container door is closed. If
ENTER is pressed during the 15 minute period, the
selected test(s) will be run. Otherwise pre-trip will be
aborted.
Any test may be interrupted by pressing the UP
ARROW key or the PRE-TRIP key. This will return the
user to the test selection mode described above, and all
machinery outputs will be de-energized.
While a given test is running, "PX-X" will be shown on
the left display, where the X's indicate the test number
and sub-test. The right display will show a countdown
time in minutes and seconds, indicating how much time
is remaining in that particular test.
a. Manual Test Operation
Individually selected tests other than the LED/Display
test will perform the operations necessary to verify the
operation of the component under test. At the
conclusion of the selected test, PASS or FAIL will be
displayed. Upon failure, the O
on alternately. This message will remain displayed for
up to three minutes, in which time a user may select
another test. If the three minute time span expires with
no user interaction, the system will terminate pre-trip
and return to control mode operation. Following any
individually selected
de-energized.
b. Calibration Gas
Typical calibration gas is composed of 5% carbon
dioxide, 95% nitrogen (0% oxygen). The purpose of the
"Cal Gas" is to calibrate the oxygen sensor and check
the carbon dioxide sensor for accuracy. P4-1 of the
Pre-Trip test calibrates the oxygen sensor to 0%. P4-2
of the pretrip test checks the carbon dioxide sensor at
5% for accuracy.
Calibration gas can be purchased locally by specifying
to any gas supplier "certified 5% carbon dioxide (4.5% to
T-305
and CO LED's will flash
2 2
test, all outputs will
5.5% is acceptable), balance nitrogen." Disposable
bottles of calibration gas are available from Carrier
Transicold service parts, P/N 07-00322-01. If calibration
gas is not available when a pretrip is done, 100%
nitrogen can be selected. When nitrogen is selected,
test P4-2 (CO check) will be skipped.
2
The calibration gas must be connected to the "Cal Gas
Port" on the front of the unit. The calibration gas is only
used during P4-1 and P4-2. The line flow rate should be
regulated to .75 l/m (1.5 scfh), and the pressure should
be regulated to less than five psi. When calibration gas
is connected to the "Cal Gas Port", a solenoid valve will
prevent flow during previous and subsequent tests.
c. Auto Test Operation from Keypad
If auto test is initiated, the system will execute a series of
consecutive tests, each related to a identifiable unit
component, without any need for direct user interface.
These tests vary in length, depending on the component
under test.
When an automatic test fails, it will be repeated once
automatically. A repeated test failure will cause "FAIL" to
be shown on the right display, with the corresponding
test number to the left. The user may then press the UP
ARROW to repeat the test or the DOWN ARROW to
skip to the next test. The system will wait indefinitely for
user input. Holding the PRE-TRIP key will terminate the
pre-trip mode operation.
When the automatic testing is allowed to run to
completion, without being interrupted with an ARROW
key being depressed, the system will exit the pre-trip
mode and return to normal control operation.
d. Auto Test Operation from Serial
Communications
If the refrigeration system is equipped with an RMU,
then pre-trip may also be initiated via remote
communications. The operation is the same as for the
Auto Test mode described above except that should a
be
test fail, the pre-trip mode will automatically terminate.
When initiated via communications, a test may not be
interrupted with an ARROW key, but the pre-trip mode
can be terminated with the PRE-TRIP key.
e. Pre-Trip Test Results
At the end of the pre-trip test selection menu, the
message "P" "rSLts" will be displayed. Pressing the
ENTER key will allow the user to see the results for all
sub tests (i.e. 1-0, 1-1, etc). The results will be displayed
as "PASS" or "FAIL" for all tests run to completion since
power up. If a test has not been run since power up,
"----------" will be displayed.
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