Carrier Streamline Scroll 69NT20-531-300 - Manual (Page 55)

T-309 4-3
3. Pre-trip may also be initiated via
communications. The operation is the same
as for the key pad initiation described below
except that should a 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.
a. Press the PRE-TRIP key. This accesses a test selec-
tion menu.
b. TO RUN AN AUTOMATIC TEST: Scroll through
the selections by pressing the UP ARROW or
DOWN ARROW keys to display AUTO, AUTO 1 or
AUTO 2 as desired and then press the AUTO key.
1. The unit will execute the series of tests without any
need for direct user interface. These tests vary in
length, depending on the component under test.
2. While tests are running, “P#-#” will appear on the left
display, where the #’s indicate the test number and
sub-test. The right display will show a countdown
time in minutes and seconds, indicating how much
time there is left remaining in the test.
CAUTION
When a failure occurs during automatic
testing the unit will suspend operation
awaiting operator intervention.
When an automatic test fails, it will be repeated once .
A repeated test failure will cause “FAIL” to be shown
on the right display, with the corresponding test num-
ber to the left. The user may then press the DOWN
ARROW to repeat the test, the UP ARROW to skip to
the next test or the PRE--TRIP key to terminate test-
ing. The unit will wait indefinitely, until the user
manually enters a command.
CAUTION
When Pre--Trip test Auto 2 runs to comple-
tion without being interrupted, the unit will
terminate pre-trip and display “Auto 2”
“end.” The unit will suspend operation until
the user depresses the ENTER key!
When an Auto 1 runs to completion without a failure,
the unit will exit the pre-trip mode, and return to nor-
mal control operation. However, dehumidification
and bulb mode must be reactivated manually if re-
quired.
c. TO RUN AN INDIVIDUAL TEST: Scroll through
the selections by pressing the UP ARROW or
DOWN ARROW keys to display an individual test
code. Pressing ENTER when the desired test code is
displayed.
1. Individually selected tests, other than the LED/Dis-
play test, will perform the operations necessary to
verify the operation of the component. At the con-
clusion, PASS or FAIL will be displayed. This mes-
sage will remain displayed for up to three minutes,
during which time a user may select another test. If
the three minute time period expires, the unit will
terminate pre-trip and return to control mode opera-
tion.
2. While the tests are being executed, the user may ter-
minate the pre-trip diagnostics by pressing and hold-
ing the PRE-TRIP key. The unit will then resume
normal operation. If the user decides to terminate a
test but remain at the test selection menu, the user
may press the UP ARROW key. When this is done
all test outputs will be de-energized and the test
selection menu will be displayed.
3. Throughout the duration of any pre-trip test except
the P-7 high pressure switch tests, the current and
pressure limiting processes are active .
d. Pre-Trip Test Results
At the end of the pre-trip test selection menu, the
message “P,” “rSLts” (pre--trip results) will be
displayed. Pressing the ENTER key will allow the user
to see the results for all subtests (i.e., 1-0, 1-1, etc). The
results will be displayed as “PASS” or “FAIL” for all the
tests run to completion since power up. If a test has not
been run since power up, “ -- -- -- -- -- ” will be displayed.
Once all pre--test activity is completed,
dehumidification and bulb mode must be reactivated
manually if required.
4.8 OBSERVE UNIT OPERATION
4.8.1 Probe Check
If the DataCORDER is off or in alarm the controller will
revert to a four probe configuration which includes the
DataCORDER supply and return air probes as the
secondary controller probes. The controller
continuously performs probe diagnosis testing which
compares the four probes. If the probe diagnosis result
indicates a probe problem exists, the controller will
perform a probe check to identify the probe(s) in error.
a. Probe Diagnostic Logic -- Standard
If the probe check option (controller configuration code
CnF31) is configured for standard, the criteria used for
comparison between the primary and secondary control
probes is:
1_C (1.8_F) for perishable set points or 2_C (3.6_F)
for frozen set points.
If 25 or more of 30 readings taken within a 30 minute
period are outside of the limit, then a defrost is initi-
ated and a probe check is performed.
In this configuration, a probe check will be run as a part
of every normal (time initiated) defrost.
b. Probe Diagnostic Logic -- Special
If the probe check option is configured for special the
above criteria are applicable. A defrost with probe check
will be initiated if 25 of 30 readings or 10 consecutive
readings are outside of the limits
In this configuration, a probe check will not be run as a
part of a normal defrost, but only as a part of a defrost
initiated due to a diagnostic reading outside of the
limits.
c.The 30 minute timer will be reset at each of the follow-
ing conditions: