Carrier VECTOR 1800 MT - Page 253

7-122
62-11039
Alarm
NO.
Steps ALARM / CAUSE CORRECTIVE ACTION
249 MICROPROCESSOR ERROR
• TRIGGER–ON: Microprocessor Input Conversion Error
•
U
N
I
T
C
O
N
T
R
O
L
:
S
h
u
t
d
o
w
n
a
n
d
a
l
a
r
m
• UNIT CONTRO
L
: Shutdown and alarm
• RESET CONDITION: Auto Reset when input conversions are valid, or Alarm may be manually
reset by turning the unit off, then back on again.
Follow the steps below until a problem is found. Once a repair or correction has been made, clear the alarm(s). (See
Note 1) Operate the unit through the appropriate modes to see if any active alarm occurs. Continue with the steps
below as necessary.
1 Check Microprocessor
a. Check Temperature Sensor Data Must be valid reading for RAT, SAT, AAT, etc.
b. Check for any Active Sensor Alarms Must all be cleared.
2 Check Microprocessor & Unit Wiring
a. Check Wiring to Micro and at input
devices to the micro.
Must not be miss wired to allow 12 VDC on any of the
sensor input circuits.
3 Reset Microprocessor
a. Turn Start/Run--Off switch off for 30
seconds, then turn back on.
Microprocessor powers up OK
b. Alarm 249 remains active. Replace microprocessor.