![background image](http://html1.mh-extra.com/html/carrier/69nt40-489-100-series/69nt40-489-100-series_operation-and-service-manual_2563838072.webp)
T-305
48
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 dis-
played.
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 conclu-
sion, PASS or FAIL will be displayed. This message
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 termi-
nate pre-trip and return to control mode operation.
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 nor-
mal 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.
4.9 OBSERVE UNIT OPERATION
4.9.1 Crankcase Heater
When the crankcase heater is installed, it will be
operational whenever the compressor is off and there is
power to the unit. The heater is connected to a set of
normally closed auxiliary contacts on the compressor
contactor.
4.9.2 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:
1. At every power up.
2. At the end of every defrost.
3. After every diagnostic check that does not fall out-
side of the limits as outlined above.
d. Probe Check
A defrost cycle probe check is accomplished by
energizing just the evaporator motors for eight minutes
at the end of the normal defrost. At the end of the eight
minute period the probes will be compared to a set of
predetermined limits. The defrost indicator will remain
on throughout this period.
Any probe(s) determined to be outside the limits will
cause the appropriate alarm code(s) to be displayed to
identify which probe(s) needs to be replaced. The P5
Pre-Trip test must be run to inactivate alarms.
4.10 SEQUENCE OF OPERATION
General operation sequences for cooling, heating and
defrost are provided in the following subparagraphs.
Schematic representation of controller action are
provided in Figure 16 and Figure 17, page 49. Refer to
Section 3 for detailed descriptions of special events and
timers that are incorporated by the controller in specific
modes of operation. Refer to section 4.11, page 52 for
emergency modes of operation.
Summary of Contents for 69NT40-489-100 Series
Page 2: ......
Page 4: ......
Page 14: ...Safety 10 T 305...
Page 28: ...4 T 305...
Page 40: ...16 T 305...
Page 50: ...26 T 305 Figure 12 Standard Configuration Report...
Page 112: ...88 T 305...
Page 164: ...140 T 305...
Page 167: ...143 T 305 Based on drawings 62 10526 Rev and 62 10736 Rev Figure 90 Electrical Schematic CA...
Page 174: ...150 T 305...