Carrier 42 GW***B series Installation Manual

2542 GW...BEnglishWater connectionsStANDARD version unit - Control panel(See fig. 35)The control panel can be reached by opening the grille and removingthe metal covers using the 3 or 4 screws (See fig. 36).Connect the power cables to terminal box connectors in accordancewith the wiring diagram and tighten firmly (See fig. 38-39-40).IMPoRtANt: Make ground connection prior to any other electricalconnections.According to the installation instructions, all devices for•disconnection from the power supply mains must have a contactopening (4 mm) to allow total disconnection according to theconditions provided for the overvoltage class III.Fix the power supply cable under the corresponding cable holder.•Make certain that the YELLOW/GREEN cable is stripped back furtherthan the others (See fig. 37-43).All the connecting cables to the fan coil unit and other accessories•should be of the H05VV-F type, with PVC insulation and in compliancewith the EN60335-2-40 standard.Unit with electric heatersto power the unit using the electric heaters, connect the powersupply cable not directly to the electronic board as in the versionswithout heaters, but using the terminal as shown in fig. 41-42.IMPoRtANt for units with electric heaters;The unit is equipped with two thermostats: one with automatic resetand one with manual reset that can be reactivated.Hot water and electric heaters can be used simultaneously onlyif the Booster Heating function is enabled (control B + kit 42N9084).Electrical connectionsWater temperature sensorThe unit has a temperature sensor installed on the inlet of the waterpipe whic is used to connect the condensate drain pump only whenwater temperature drops below a value for which pump connection isrequested.CheckingOn the unit startup, check if water flows correctly from the pump orcheck the pipe slope and make sure the pipes are not obstructed.To make water connections to the heat exchanger or the valvesuse threaded joints and suitable materials that can ensure perfecttightness.The unit is provided with inlet and outlet female connections forboth 2 and 4 pipe models. An air bleed valve is also provided (fig. 26),which can be adjusted using a 8 mm wrench.Motorized valve and controlThe unit control circuit only allows opening of the motorized valve•when the fan motor is working.When the thermostat asks for cooling, outlet 1 of terminal TB3 on•the electronic board is powered at 230V (and the correspondingchilled water valve is energized). When the thermostat asks forheating, outlet 2 of terminal TB3 on the electronic board is poweredat 230V (and the corresponding hot water valve or electric heater isenergized).The control circuit ensures that the condensate discharge pump•works continuously while the thermostat, asking for cooling, keepsthe cold water regulating valve open.WARNING : the valve is not only necessary to control the roomtemperature, but also to stop the cold water flow to the coil incase of an abnormal condensing water level rise in the drain pan.If there is an abnormal condensing water rise in the drain pan (for•example: possible defective drain, pump malfunction, fan motor notworking) causing the opening of the float switch contact (FS), thecontrol circuit either operates the condensate drain pump, or at thesame time closes the regulating valve, stopping the cold water flowtowards the coil and avoiding further condensation.ControlThe water flow has to be controlled:by installing the motorized thermo-electric valves supplied as•accessoryorby installing motorized field supplied valves.•Models Connectionsdimension (Ø) Models Connectionsdimension (Ø)004 3/4" 012 1"008 3/4" 016 1"010 3/4" 020 1"004* 1/2" 020* 3/4"008* 1/2" *Hot water circuits, four-pipeversion010* 1/2"to drain the unit completely, refer to “SYStEM DRAINAGE” in theMaintenance section.