Carrier 30GX Installation, Operation And Maintenance Instructions

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

9Start/stop contactSetpoint selection contactHeat/cool contactHeat reclaim selection contactDemand limit contactEvaporator water loopcontrol contact3.4.5 - Remote stop/start volt-free contact**The remote stop/start contact is only taken into account if theunit is in remote control operating type (rEM). See section4.2.2.Remote stop/start connectionsKey:Contact open: unit stoppedContact closed: start commandNOTE: In exceptional circumstances this contact can beconfigured as active (configuration by Carrier Service) if theunit operates in CCN mode as part of a master-slave link (seesection 5.18).3.4.6 - Remote volt-free contact for cooling temperaturesetpoint selection**The remote contact for cooling setpoint selection is only takeninto account if the unit is in remote control operating type (rEM).See section 4.2.2.Connection for remote setpoint selectionKey:Contact open: cooling setpoint 1Contact closed: cooling setpoint 23.4.7 - Remote heat/cool volt-free contact**The remote heat/cool selection contact is only taken intoaccount if the unit is in remote control operating type (rEM).See section 4.2.2.Connection for remote heat/cool selectionKey:Contact open: condensing setpoint 1 / reclaim mode not selectedContact closed: condensing setpoint 2 / reclaim mode selected3.4.9 - Demand limit volt-free contact**This contact is used to activate the demand limit function onthe unit (see sections 4.2.10, 4.2.7 and 5.6). This contact isactive whatever the operating type of the unit.Connection for demand limit contactKey:Contact open: demand limit disabledContact closed: demand limit active3.4.10 - Evaporator water loop control and condenser waterflow or thermostat box control volt-free contacts**If these contacts open, the unit is shut down or prevented fromrestarting and an alarm is raised. They are used to controlevaporator and condenser water flow on water-cooled units orto control the thermostat box temperature on air-cooled units.Evaporator water-loop control contact connection63 6463 643.4.4 - Evaporator heater contactor controlThe evaporator heater contactor can be supplied with 24 V a.c.and a maximum current of 0.5 A* between terminals 41 and 12.Fig. 6 - Evaporator heater connectionsKeyContact open: coolContact closed: heat3.4.8 - Remote heat reclaim volt-free contact**This control is used to select the second condensing setpoint orthe heat reclaim mode. It is only taken into account if the unitis in remote control operating type (rEM). See section 4.2.2.Connection for heat reclaim mode selection35The evaporator water flow control contact is factory-wired (34-35). The evaporator pump must be controlled and connectedbetween terminals 34 and 36.Notes:* Each output (sections 3.4.1 to 3.4.4) can be suppliedindividually at 24 V a.c. - 0.5 A maximum, providedthe total does not exceed 1 A.** The volt-free contacts (sections 3.4.5 to 3.4.10) areinternally supplied by electric boards under 24 V a.c.from 15 to 20 mA. The field-supplied volt-free contactmust be compatible with these electrical specifications.