Carrier AQUASNAP 30RB060-390 Controls, Start-up, Operation, Service And Troubleshooting Instructions

Also see for AQUASNAP 30RBA315: Installation instructions

71outside the range of –40 F (–40 C) to 240 F (115.6 C). Thisalarm is for units with the heat reclaim option only.Action to be Taken — NoneReset Method — Automatic, the alarm will reset once thethermistor reading is within the expected range.Possible Causes — If this condition is encountered, check thefollowing items:• Check the sensor wiring to the heat reclaim board.• Check for a faulty thermistor.• Check the board for a faulty channel.• Confirm unit configuration.th.10 — OAT Thermistor FailureCriteria for Trip — If the outdoor air temperature as measuredby the thermistor is outside of the range –40 F (–40 C) to 240 F(115.6 C).Action to be Taken — Unit shuts down under normal condi-tions or is not allowed to start. Temperature reset based onoutdoor air temperature will be disabled.The OAT sensor controls the cooler heaters. If this sensorfails, the cooler heaters will be energized when the machinestages to 0.Reset Method — Automatic, the alarm will reset once thethermistor reading is within the expected range and Tempera-ture reset based on outdoor-air temperature will be enabled.Possible Causes — If this condition is encountered, check thefollowing items:• Check the sensor wiring to the main base board.• Check for a faulty thermistor.For thermistor descriptions, identifiers and connections, seeThermistors on this page.th.11 — Master/Slave Common Fluid ThermistorCriteria for Trip — This alarm criterion is checked whether theunit is ON or OFF and has been configured for Dual ChillerControl. The alarm will be triggered if the Dual ChillerCommon Fluid temperature as measured by the thermistor isoutside of the range –40 F (–40 C) to 240 F (115.6 C).Action to be Taken — Dual Chiller Control disabled. Unitsoperate as a stand-alone machine.Reset Method — Automatic, once the thermistor reading iswithin the expected range. The Dual Chiller algorithm willresume once the alarm is cleared.Possible Causes — If this condition is encountered, check thefollowing items:• Check the sensor wiring to the main base board.• Check for a faulty thermistor.For thermistor descriptions, identifiers and connections, seeThermistors on this page.Suction Gas Thermistorth.12 — Circuit Ath.13 — Circuit Bth.14 — Circuit CCriteria for Trip — This alarm criterion is checked whether theunit is ON or OFF. If the suction gas temperature as measuredby the thermistor is outside of the range –40 F (–40 C) to 240 F(115.6 C), the alarm will be triggered.Action to be Taken — The affected circuit shuts downnormally.Reset Method — Automatic, once the thermistor reading iswithin the expected range. The affected circuit will restart oncethe alarm has cleared.Possible Causes — If this condition is encountered, check thefollowing items:• Check the sensor wiring to the EXV board.• Check the board for a faulty channel.• Check for a faulty thermistor.For thermistor descriptions, identifiers and connections, seeThermistors on this page.Condenser Subcooling Liquid Thermistorth.18 — Circuit Ath.19 — Circuit BCriteria for Trip — Tested when the unit is On or Off. If thetemperature as measured by the sensor is outside of the rangeof –40 F (–40 C) to 240 F (115.6 C). This alarm is for unitswith the heat reclaim option only.Action to be Taken — The unit will return to the air cooledmode.Reset Method — Automatic, the alarm will reset once the read-ing is within the expected range.Possible Causes — If this condition is encountered, check thefollowing items:• Check the sensor wiring to the EMM HR.• Check for a faulty thermistor.• Confirm unit configuration.th.21 — Space Temperature Sensor FailureCriteria for Trip — This alarm criterion is checked whether theunit is ON or OFF and if Space Temperature Reset has beenenabled. If the outdoor-air temperature as measured by thethermistor is outside of the range –40 F (–40 C) to 240 F(115.6 C), the alarm will be triggered.Action to be Taken — Unit operates under normal control.Temperature Reset based on Space Temperature is disabled.Reset Method — Automatic, once the thermistor reading iswithin the expected range. The Space Temperature Reset willresume once the alarm has cleared.Possible Causes — If this condition is encountered, check thefollowing items:• Check the sensor wiring to the energy managementmodule.• Check the board for a faulty channel.• Check for a faulty thermistor.For thermistor descriptions, identifiers and connections, seeThermistors below.Sensors — The electronic control uses up to six thermis-tors to sense temperatures and up to six transducers to sensepressure for controlling chiller operation. These sensors areoutlined below.Thermistors (Tables 45-46B) — Thermistors that aremonitoring the chiller’s operation include: cooler entering wa-ter, cooler leaving water, dual chiller leaving water, compressorsuction gas temperature, and outside air thermistors. Thesethermistors are 5 kat 77 F (25 C) and are identical in temper-ature versus resistance. The space temperature thermistor is10 k at 77 F (25 C) and has a different temperature vs.resistance.COOLER LEAVING FLUID SENSOR — On all sizes, thisthermistor is installed in a friction fit well in the leaving waternozzle of the cooler. See Fig. 34 and 35.COOLER ENTERING FLUID SENSOR — On all sizes,this thermistor is factory-installed in a friction fit well in theentering water nozzle of the cooler.DUAL CHILLER LWT — On duplex chillers, 30RB315-390, a factory-supplied, field-installed friction fit well andthermistor are installed in the common supply water header ofthe two modules.COMPRESSOR RETURN GAS TEMPERATURE — Thisthermistor is factory-installed in a friction fit well located in thecommon suction line for the circuit. There is one thermistor foreach circuit.