Carrier 42EP Installation, Operation And Maintenance Instructions

Also see for 42EP: Installation, operation and maintenance instructions

EN4.9.1 - Optional balancing valvesTwo-way valve with water flow balancing function isembedded with a differential pressure controller (withor without pressure test points to control the water flowsettings). The setting of the valve is shown in Fig. 16.The manual control knob (16a) is ready fitted to protectvalve stem and pre-set mechanism and facilitatesmanual control of valve during commissioning.Setting procedure:- Remove control knob from the valve (16a)- Loosen knurled nut (16b).- Adjust the desired dial setting with the white knob(16c) - see table below.- Retighten knurled nut by hand (16d).WARNING: The valves have to be open whenflushing or pressure testing the system. Strongpressure impacts can damage closed valves.Differential pressure across the valve’s control pathis not allowed to exceed 400 kPa.4.9.2 - 230 V - ActuatorsTwo types of valve actuators are provided: electrothermal actuator (on/off control) or modulating actuator(3-point).The actuator supply is 230 V a.c.4.9.3 - 24 V - ActuatorsThree types of valve actuators are provided: one electrothermal actuator (on/off control) or two modulatingactuators (3-point or 0-10V).Both modulating actuators can be operated manuallywith a hexagonal key. The 0-10V command voltagerange of the modulating actuator can also be adjusted.The actuator supply is 24 V a.c.NOTE: 24V actuators are not compatible with Carriercontrollers (Thermostats A/B/C/D, WTC & NTC).4.9.4 - Actuator replacement procedureThe actuators on both the chilled water and the hot watervalves may be replaced in case of failure.WARNING: Do not connect on the same neutral wirethe valve actuator 24 Vac and the controller.- Disconnect the power supply to the unit beforecarrying out any work on a unit.- Disconnect the actuator power supply cable.• 230 V type actuator used with the Carriernumeric controller: Disconnect the actuatorpower supply cable fitted with a quick connector.• 230 V actuator used with an electronicthermostat: Remove the plastic protection coverheld in place with two screws. Disconnect theactuator power supply cable connected to thequick connector. This can be done by pressingdown the spring tongue using a screwdriver andpulling out the wire from the appropriate terminal.- Uncouple the faulty actuator. Refitting is by thereversal of the procedure described above.WARNING: Ensure that the actuator is firmly screwedto the valve body (maximum torque 15 N·m).4.9.5 - Valve body replacement procedure- Disconnect the power supply before carrying outany work on a unit.- Close the isolating valves on the manifolds.- Remove flexible water pipes.- Remove the valve actuators taking care to identifythe cooling and heating valves.- Disconnect the flexible condensate drain pipe whichis held in place by a collar (the collar is not suppliedby Carrier).Remove the two-way or four-way waterflow control valve bodies. Depending how the unit isconfigured, the four-way valve coupling may be fittedwith a heating/cooling changeover switch, if so donot remove it.- Fit the new valve body to the coil (fit new gaskets).- Reconnect the flexible condensate drain pipewhich is held in place by a collar (the collar is notsupplied by Carrier).- Refit the valve actuators taking care to ensure thatthey are correctly fixed to the valve body.- Reconnect the flexible water pipes by tighteningthe union nuts. Retighten all the water connectionsand ensure that all gaskets have been changedand correctly fitted (maximum torque 15 N·m).- Open the isolating valves on the manifolds andpurge all air from the system.- Check that there are no leaks and reconnect thepower to the unit.WARNING: When replacing a valve always ensurethat the direction of flow through the valve is asshown by the arrow on the valve body. If thedirection of flow is wrong, the valve body willdeteriorate rapidly and the flow control will bedistorted.4.10 - Flexible pipe option■ Minimum bending radius:- Non-insulated pipes 72 mm- Insulated pipes 106 mm.Connections 1/2” diameter (female)4 - COMPONENTS AND MAINTENANCE19