Carrier 30GX Installation, Operation And Maintenance Instructions

Also see for 30GX Series: Installation, operation and maintenance instructions Installation, operation and maintenance instructions

824 V a.c. supply 24 V a.c. supplyCon-tactorPumpEconomizer pressure sensorsThese sensors are used to measure the intermediate pressurebetween high and low pressure. They are used to control the oilpressure differential. They are located on the suction line of theeconomiser circuit (for units equipped with economizers) or onthe cooling line of each motor.3.3.7 - ThermistorsThese all have similar characteristics.Evaporator entering and leaving water temperature sensorThe evaporator entering water temperature sensor and theleaving water temperature sensor are installed in the enteringand leaving side water box.Discharge gas sensorThis sensor is used to measure the discharge gas temperature,and permits control of the discharge temperature superheat. Itis located in the discharge line of each circuit (oiler entering orleaving line, depending on the model).Motor sensorThis is used to control the motor temperature of eachcompressor. The terminals of this sensor are situated on thecompressor terminal board.Evaporator liquid level sensorThis is used to measure the refrigerant charging level. Itensures optimised flow control in the evaporator, and isinstalled at the top of the evaporator.Condenser entering and leaving water temperature sensorsThese are used to control the heating capacity on heat pumps.In cooling only units they have no control function. They areinstalled in the common condenser entering and leaving line.Heat reclaim condenser entering/leaving watertemperaturesThese sensors measure the entering and leaving watertemperatures of heat reclaim condensers and are used on air-cooled units. They may be fitted as options.Temperature setpoint reset sensorThis is an optional 0-10 V sensor which can be installedremotely from the unit. It is used to reset the cooling andheating setpoint on the unit as a function of either the outdoorair temperature or ambient room temperature. The sensor is notsupplied by Carrier. Its characteristics must be configured byCarrier Service. See section 3.4.10 for connection instructions.3.4 - Connections at customer’s terminal blockThe connections below are available at the customer’s terminalblock. Some of them can only be used in special operatingmodes. For further details see the sections that describe thefunctions (section 5) and the configurations (section 4.2.10).NOTE: The bridge between terminals 32, 63 and 65 on thecustomer’s terminal block must not be removed.3.4.1 - Fault reporting on circuits A and BThese are live contacts. They must be supplied with 24 V a.c.and maximum current 0.5 A*.Fig. 3 - Fault report alarm connectionsNOTE: To obtain a volt-free dry alarm contact, these outputsmust be interfaced with a relay supplied with 24 V a.c. (CarrierPart No. —OK—12AC-034—EE).3.4.2 - Evaporator pump contactor controlThe evaporator pump contactor can be supplied with 24 V a.c.and a maximum current of 0.5 A* between terminals 12 and90.Fig. 4 - Evaporator pump connections3.4.3 - Condenser pump contactor controlThe condenser pump contactor can be supplied with 24 V a.c.and a maximum current of 0.5 A* between terminals 95 and 12.Fig. 5 - Condenser pump connectionsCon-tactorALARM ALARMPumpAlarmAlarm