Carrier 69NT40-541-306 Operation And Service Download

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4–9

T-354

Some alarms requiring compressor shutdown have time delays before and after to try to keep the compressor on
line. An example is alarm code “LO”, (low main voltage), when a voltage drop of over 25% occurs, an indication is
given on the display, but the unit will continue to run.

An alarm is indicated by flashing an alarm code on the display panel, and for some alarms, by the alarm light illuminating.

When an Alarm Occurs:

a. The red alarm light will illuminate for “20 series” alarms.

b. If a detectable problem is found to exist, its alarm code will be alternately displayed with the set point on

the left display.

c. The user should scroll through the alarm list to deter mine what alarms exist or have existed. Alarms

must be diagnosed and corrected before the Alarm List can be cleared.

To Display Alarm Codes:

a. While in the Default Display mode, press the ALARM LIST key. This accesses the Alarm List Display

Mode, which displays any alarms archived in the Alarm Queue.

b. The alarm queue stores up to 16 alarms in the sequence in which they occurred. The user may scroll

through the list by depressing an ARROW key.

c. The left display will show “AL##”, where ## is the alarm number sequentially in the queue.

d. The right display will show the actual alarm code. “AA##” will display for an active alarm, where “##” is

the alarm code. Or “IA##” will display for an inactive alarm (refer to

Table 4–6

e. “END” is displayed to indicate the end of the alarm list if any alarms are active.

f. “CLEAr” is displayed if all alarms are inactive. The alarm queue may than be cleared by pressing the

ENTER key. The alarm list will clear and “-----” will be displayed.

NOTE

AL26 is active when all of the sensors are not responding. Check the connector at the back of the con-
troller, if it is loose or unplugged, reconnect it. Then run a pretrip test (P5) to clear AL26.

4.5

UNIT PRE-TRIP DIAGNOSTICS

Pre-trip diagnostics is an independent controller function that will suspend normal refrigeration controller activities
and provide preprogrammed test routines. The test routines include Auto Mode testing, which automatically pre-
forms a pre programmed sequenced of tests or Manual Mode testing, which allows the operator to select and run
any of the individual tests.

CAUTION

Pre-trip inspection should not be per formed with critical temperature cargoes in the container.

CAUTION

When Pre-Trip key is pressed, dehumidification and bulb mode will be deactivated. At the com-
pletion of Pre-Trip activity, dehumidification and bulb mode must be reactivated.

Testing may be initiated by use of the keypad or via communication, but when initiated by communication, the con-
troller will execute the entire battery of tests (auto mode).

At the end of a pre-trip test, the message "P," "rSLts" (pretest results) will be displayed. Pressing the ENTER key
will allow the user to see the results for all subtests. The results will be displayed as "PASS" or "FAIL" for all the
tests run to completion.

A detailed description of the pre-trip tests and test codes is provided in

Table 4–7

. Detailed operating instructions

are provided in

Section 5.8