Carrier 42NL series Installation, Operation And Maintenance Instructions

Also see for 42NH series: Installation, operation and maintenance instructions Original instructions

Contents

Carrier 42NL series Installation, Operation And Maintenance Instructions Manual pdf 24 page image

24ENGLISH• Refit the valve actuators taking care to ensure thatthey are correctly fixed to the valve body.• Reconnect the flexible water pipes by tightening theunion nuts. Retighten all the water connections andensure that all gaskets have been changed andcorrectly fitted (maximum torque 15 N·m).• Open the isolating valves on the manifolds and purgeall air from the system.• Check that there are no leaks and reconnect the powerto the unit.WARNING: When replacing a valve always ensure thatthe direction of flow through the valve is as shown by thearrow on the valve body. If the direction of flow is wrong,the valve body will deteriorate rapidly and the flow controlwill be distorted.4.9 - Flexible pipe optionMinimum bending radius:• Non-insulated pipes 72 mm• Insulated pipes 106 mm.Connections for unit size 2, 3, 4 and 5: 1/2’’ diameter (female)Connections for unit size 6 and 7: 3/4’’ diameter (female)4.10 - Optional electric heaterWARNING: Disconnect the power supply before carryingout any work on the unit.If the electric heater develops a fault, it must be replaced;this requires the removal of the fan motor assembly: Fig. 12.CAUTION: Do not touch the live metal heater elementswhen the electric heater is connected to the power supply.Electric heater replacement procedure:• Remove the filter.• Remove the fan motor assembly access panel.• Identify and note the fan speeds wired to the auto-transformer terminal block. Disconnect the powersupply cable.• Remove the fan motor assembly.NOTE: Be careful not to touch the fan blades during theremoval process to avoid unbalancing the fans.• Disconnect the electric heater power supply cablesand remove them through the cable conduit.• Unscrew the defective heater(s) and replace it (them).• Replacement of the fan motor assembly is by thereversal of the above procedure.Carrier Electronicthermostat type B is embedded with Electric heaterrelay 8 Amps. Accordingly, Carrier requires anadditional protection relay for electric heater withabove 1400 W capacity.All units delivered with an electrical box or a Carriercontroller are always equipped with a relay if the capacityof the electrical heater is above 1400W.WARNING : In case of customer supplied controller, it isthe responsability of the installer to set up an additionalprotection relay corresponding to the electrical heatercapacity.4.11 - Optional water sensorA water temperature sensor can be provided. It has to beinstalled on the water circuit as described below :• For 2-pipe coil : the sensor shall be installed on acooling water pipe (for change-over function). Thesensor is installed on a part where the water flow iscontinuous.• For 4-pipe coil : the sensor shall be installed on aheating water pipe (for cold-draft function thatprevents the operation of the unit when the heatingnetwork is off).NOTE: In case of unit with an electrical box (for CarrierThermostats), a “switch” is provided as an option insteadof the water sensor.4.12 - Optional condensate pumpThe condensate pump can be delivered with the unit but isnot assembled. The pump assembly instruction is describedin Fig. 18.• Fit the pump support on the edges of the drain pan(Fig 18.1)• Connect the rubber pipe on both sides (Fig 18.2)• (Optional) It is recommended to lower the positionof the pump in order to reduce the volume of standingwater in the drain pan. (Fig 18.4)• Plug the electrical wires and the outlet pipe (6mminner diameter); (Fig 18.5)• Check the sealing of the hydraulic connection of thecondensate pump and condensate recovery (Fig 18.3)The meaning of the electrical wires is described below:• Brown - Blue wires : Electrical supply 230V 50/60Hz• Black - Grey wires : Alarm contact Normally Closed(NC) 250V/8A maxi.