Check Suction Temperature Sensor (Cst) - Carrier VECTOR 1550 Series Operation & Service Manual

Alarm
Steps
NO.
127

CHECK SUCTION TEMPERATURE SENSOR (CST)


TRIGGER-ON: Sensor is not within the range of -47 to +70°C (-53 to +158°F)

UNIT CONTROL: Engine and standby operation: alarm only.

RESET CONDITION: Auto Reset or alarm may be manually reset via keypad or by turning the unit
off, then back on again.
NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, the active
alarm should clear itself (refer to reset condition above). Operate the unit through the appropriate modes to see if
any active alarm occurs. Continue with the steps below as necessary.
1 Check Sensor Wiring
a. Inspect sensor & connector pins &
terminals. (See wiring schematic
Section 10.)
b. Energize sensor circuit.
c. Check for voltage at the sensor
plug between pins A (+) and B
(ground).
Check Sensor
2
a. Check Sensor resistance. (Refer to
Note 3 page 7-2.)
3 Check Circuits With Another Sensor
a. Substitute known good sensor and
clear alarm. Start unit and run for
30 seconds.
b. Check to see if alarm re-occurs.
ALARM / CAUSE CORRECTIVE ACTION
No physical damage to sensor.
No damage, moisture or corroded pins in plug.
Refer to Note 2 Page 7-2.
Voltage should be approximately 12 VDC.
Refer to Section 8.7.7 for complete table of tempera-
tures and resistance values.
Alarm should not come on. (Install new sensor if nec-
essary.)
7-65
62-61753-21