Carrier VECTOR 6500 Operation & Service Manual page 134

WARNING
Advance microprocessor equipped units
may start automatically at any time the Main
Power switch is not in the OFF position.
Also, the unit may be fitted with two way
communication equipment that will allow
starting of the unit from a remote location
even though the switch is in the OFF posi-
tion.
WARNING
Be aware of HIGH VOLTAGE supplied at the
power plug or from the generator. When
performing service or maintenance proced-
ures: ensure any two way communication is
disabled in accordance with the manufac-
turer's instruction, ensure the Main Power
Switch is in the OFF position and, whenever
practical, disconnect the high voltage
source, lockout/tagout the receptacle and
disconnect the negative battery connec-
tion. NEVER dis-assemble the generator:
HIGH MAGNETIC FIELD INSIDE! This field
can interfere with cardiac implants such as
pacemakers and defibrillators.
7.1 INTRODUCTION
This section provides guidance for troubleshooting
alarms. The alarm light will be illuminated when there is
one (or more) alarm(s) stored in the microprocessor.
Instructions for reviewing the alarm lists are provided in
sections 3.11 & 3.12.
When an alarm occurs, look through both Active and
Inactive alarm lists in the microprocessor and make
note of all alarms. Each alarm begins with an A (active)
or I (inactive) followed by an alarm number and
description. Alarms are listed in this guide by alarm
number in ascending order.
Before beginning to actually troubleshoot an alarm,
visually inspect the unit, in particular the area of the unit
that is causing a problem. In many cases the cause of
the problem will be obvious once a visual inspection is
performed. For those cases where the cause of the
SECTION 7
ALARM TROUBLESHOOTING
7−1
problem is not obvious, this troubleshooting guide will be
of assistance.
Troubleshooting should begin with the first alarm that
appears in the active alarm list. The first alarm that
appears is the last alarm that was recorded. Other
alarms in the list may have contributed to the
occurrence of the first alarm.
The check items in the troubleshooting guide are listed
in order of their likeliness of occurrence and ease of
testing. We recommend that you follow the order in
which they are presented; however, there may be times
when situations or experience lead a to the use of a
different order. For example, if the trailer is loaded,
condensing unit checks should be done first, even
though some evaporator section checks may be listed
before them.
When the cause of the problem is corrected, it is not
necessary to continue through the remainder of the
steps. Some active alarms will inactivate themselves
automatically once the cause has been corrected.
Alarms that do not inactivate themselves automatically
must be cleared manually. (See Note 1 page 7−2.)
When repairs are completed, run the unit through a
Pretrip cycle and verify that no further active alarms
occur. Also, the inactive alarm list should be cleared so
that there are no 'old' alarms in memory when the unit
leaves the repair facility.
If the message CHECK WIRES FROM MICRO TO
KEYPAD appears in the MessageCenter, there is a
communication error between the keypad and the
microprocessor. With no communication, there will not
be an associated alarm. Should this occur, check the
wire connections behind the keypad assembly, at the
keypad itself (remove the rear cover to check), and at
connector 6MP on the microprocessor. Check for
microprocessor status led blinking at 1 second rate (1
second ON/1 second OFF).
When working on the refrigeration system, an
accurately calibrated manifold gauge set should always
be installed. It is not necessary to connect an additional
high pressure gauge at the liquid line service valve. The
compressor suction pressure, compressor discharge
pressure and evaporator outlet pressure can be read in
the unit data list.
In high or low ambients it may be necessary to cool or
warm the refrigerated compartment temperature before
performing specific
compartment is not loaded with perishable product.
tests providing that
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the