Carrier 30XW150-400 Alarm 10 - Master/Slave Common Fluid Thermistor th.11, a faulty thermistor

Alarm 10 — Master/Slave Common Fluid Thermistor (th.11)

Criteria for Trip — This alarm criterion is tested whether the unit is ON or OFF. The alarm will be tripped if the unit is configured as a master or a slave (Master/Slave Select, MSSL), leaving temperature control is selected (Entering Fluid Control, EWTO), and if the temperature measured by the CHWS (chilled water sensor) fluid sensor is outside the range of –40 to 245 F (–40 to 118.3 C).

Action to be Taken — Master/slave operation is disabled and the chiller returns to stand alone mode.

Reset Method — Reset is automatic when the thermistor read- ing is inside the range of –40 to 245 F (–40 to 118.3 C).

Possible Causes — If this condition is encountered, check the following items:

•sensor wiring to the Main Base Board

•a faulty thermistor

See the Thermistors section on page 56 for thermistor de- scription, identifiers and connections.

Suction Gas Thermistor

Alarm 11 — Circuit A (th.12)

Alarm 12 — Circuit B (th.13)

Criteria for Trip — This alarm criterion is tested whether the unit is ON or OFF. If the suction gas temperature as measured by the thermistor is outside of the range –40 to 245 F (–40 to 118.3 C).

Action to be Taken — The affected circuit shuts down normally.

Reset Method — Automatic, once the thermistor reading is within the expected range. The affected circuit will restart once the alarm has cleared.

Possible Causes — If this condition is encountered, check the following items:

•sensor wiring to the EXV board

•board for a faulty channel

•a faulty thermistor

See the Thermistors section on page 56 for thermistor de- scription, identifiers and connections.

Circuit Discharge Gas Thermistor Sensor Failure

Alarm 14 — Circuit A (th.15)

Alarm 15 — Circuit B (th.16)

Criteria for Trip — This alarm criterion is tested whether the unit is ON or OFF. The alarm is tripped if the temperature measured by the Outdoor Air Thermistor sensor is outside the range of –40 to 245 F (–40 to 118.3 C).

Action to be Taken — The unit shuts down normally, or is not allowed to start.

Reset Method — Automatic, the alarm will reset once the thermistor reading is within the expected range.

Possible Causes — If this condition is encountered, check the following items:

•sensor wiring to the CPM board

•a faulty thermistor

•a faulty channel on the board

See the Thermistors section on page 56 for thermistor descrip- tion, identifiers and connections.

Condenser Subcooling Liquid Thermistor

Alarm 17 — Circuit A (th.18)

Alarm 18 — Circuit B (th.19)

NOTE: Alarms 17 and 18 are not used or supported. If this condition is encountered, confirm machine configuration.

Alarm 19 — Space Temperature Sensor Failure (th.21)

Criteria for Trip — This alarm criterion is checked whether the unit is ON or OFF and if Space Temperature Reset has been enabled. This alarm is generated if the outdoor-air temperature as measured by the thermistor is outside of the range –40 to 245 F (–40 to 118.3 C).

Action to be Taken — Unit operates under normal control. Temperature Reset based on Space Temperature is disabled. Reset Method — Automatic, once the thermistor reading is within the expected range. The Space Temperature Reset will resume once the alarm has cleared.

Possible Causes — If this condition is encountered, check the following items:

•sensor wiring to the Energy Management Module

•board for a faulty channel

•a faulty thermistor

For thermistor descriptions, identifiers and connections, see the Thermistors section.

Alarm 20 — Cooler Heater Feedback Sensor Thermistor (th.23)

NOTE: Alarm 20 is not used or supported. If this condition is encountered, confirm machine configuration.

Economizer Gas Thermistor

Alarm 21 — Circuit A (th.24)

Alarm 22 — Circuit B (th.25)

Criteria for Trip — This alarm criterion is tested whether the unit is ON or OFF. The alarm is tripped if the Economizer gas reading is outside the range of –40 to 245 F (–40 to 118.3 C).

Action to be Taken — The unit shuts down normally, or is not allowed to start.

Reset Method — Automatic, the alarm will reset once the thermistor reading is within the expected range.

Possible Causes — If this condition is encountered, check the following items:

•sensor wiring to the EXV board

•a faulty thermistor

•a faulty channel on the board

See the Thermistors section on page 56 for thermistor descrip- tion, identifiers and connections.

Discharge Transducer

Alarm 26 — Circuit A (Pr.01)

Alarm 27 — Circuit B (Pr.02)

Criteria for Trip — The criterion is tested whether the circuit is ON or OFF. This alarm is generated if the voltage as sensed by the MBB or Fan Board C (FBC) is 0 vdc, which corresponds to the Navigator™ display of –7 psi (–48.3 kPa).

Action to be Taken — The circuit is shut down normally, or not allowed to start.

Reset Method — Automatic, once the transducer voltage is greater than 0 vdc, which corresponds to the Navigator display of a value greater than –7 psi (–48.3 kPa).

Possible Causes — If this condition is encountered, check the following items:

•sensor wiring to Main Base Board (Alarms 24 and 25)

•sensor wiring to Fan Board C (Alarm 26)

•board for a faulty channel

•for a faulty transducer

•confirm unit configuration

Suction Pressure Transducer Failure

Alarm 29 — Circuit A (Pr.04)

Alarm 30 — Circuit B (Pr.05)

74