Carrier NDK33BN0KB, Operation & Service Manual

Page: 53 / 270

62-61753-21 3-5
TIP
Pretrip may be stopped by the user by ei-
ther turning the unit off then back on again, or
by pressing and holding the "=" Key for
5 seconds. "PRETRIP STOPPED BY USER"
will display in the MessageCenter.
Once Pretrip is started: If the unit is running (engine or
standby), the microprocessor will shut the unit down.
If the unit is not running Pretrip will begin.
NOTE
Before completing Pretrip, the microprocessor
looks at the status of alarms and if certain
alarms are active (for example: Low Fuel
Warning, Check Engine Oil Level, Check
Coolant Level, Check Coolant Temperature),
Pretrip will display "FAILED", indicating that
the unit is not ready to be sent out for a load,
but that the alarm list should be checked and
all present alarm situations corrected.
TIP
It is always a good idea to clear all alarms
from both Alarm Lists before starting Pretrip.
The technician will then know that any alarms
present following Pretrip occurred during
Pretrip, and are not old alarms that had not
been cleared.
NOTE
The operator MUST be present and validate
this test by watching the microprocessor dis-
play during Test 1. The microprocessor will
turn on all segments of the LCD and LED dis-
play.
Test 1 - Display Test
The microprocessor activates the display, and both
lights on the Light Bar. This test will last 5 seconds. All
segments of the display, all LEDs on the microproces-
sor and both lights of the Light Bar will be on during
this test. This portion of the Pretrip check requires that
the operator determines PASS or FAIL. A defective
display is indicated if: any LCD / LED segments are
not visible or any LEDs or lights do not illuminate. Any-
thing that fails during this test should be repaired at the
conclusion of the Pretrip cycle. Pretrip will continue
regardless of the outcome of this test. A faulty display
or light bar will not affect the operation of the unit, but
will affect what is displayed during unit operation.
Test 2 - Sound and 12VDC Electrical
Component Amperage Check
At the beginning of this test the microprocessor acti-
vates the buzzer for 5 seconds, the operator is to de-
termine if the sound test is PASS or FAIL. If the sound
test fails it should be repaired at the conclusion of the
Pretrip cycle. Pretrip will continue regardless of the
outcome of the sound test. A faulty buzzer will not
affect the operation of the unit, but will lead to opera-
tion without proper audible warning on startup.
Test 2 will continue with a check of the amperage (cur-
rent) draw of the following components:

Battery DC Current (All Components Turned Off)

Unloader Solenoid Valve (USV)

Economizer Solenoid Valve (ESV)

Liquid Injection Valve (LIV)

Speed Control Solenoid (SCS)

Glow Plugs (GP)

Fuel Solenoid (FS)

Condenser Motor Contactor (CDCON)

Evaporator Motor Contactor (EVCON)

Compressor Contactor (CCON)

Generator Contactor (GENCON)

Power Source Contactor PSCON or PSCON2)

Heater 1 Contactor (HTCON1)

Heater 2 Contactor (HTCON!2
Each component will be individually checked for prop-
er current draw. An alarm will be displayed for any
component testing outside the current range (amps).
Test 3 - Temperature Sensor Check
Check the condition of all of the system temperature
sensors.
Test 3 will last approximately 5 seconds. If a problem
is detected with any of the sensors, the corresponding
alarm will be displayed.
Test 4 - Engine Low Speed
The engine starts up in Low Speed with condenser
fans on.
The microprocessor verifies that engine rpm
is in low speed range. If the engine is not operating
within the low speed range, the "CHECK LOW SPEED
RPM" alarm will be displayed.
Test 5 - Engine High Speed
The engine switches to High Speed and energizes
HTCON1 and HTCON2.
The microprocessor verifies
that engine rpm is in high speed range. If the engine is
not operating within the high speed range, the
"CHECK HIGH SPEED RPM" alarm will be displayed.
Test 6 - Engine Low Speed 2
The engine switches back to Low Speed and heaters
turn off. The microprocessor verifies that engine rpm is
in low speed range. If the engine is not operating with-
in the low speed range, the "CHECK LOW SPEED
RPM" alarm will be displayed.
Test 7 - Electric Heater Amperage Check
Each heater contactor is energized individually and
check for proper current draw. An alarm will be dis-
played for any heater testing outside the current range
(amps).