Carrier 42BJ MCI LEC Installation Instructions Manual

Contents

Carrier 42BJ MCI LEC Installation Instructions Manual Manual pdf 12 page image

124.2 - Water coil4.2.1 - Coil removal procedureWARNING: Disconnect the power supply to the unit beforecarrying out any work on the unit.• Close the isolating valves on the manifolds.• Unscrew the union nuts to disconnect the flexiblewater pipes.• Remove the valve actuators taking care to identify thecooling and heating valves.• Disconnect the flexible condensate drain pipe which isheld in place by a collar (the collar is not supplied byCarrier).• Remove the two-way or three-way water flow controlvalve bodies. Depending how the 42BJ ICM LEC isconfigured, the three-way valve coupling may be fittedwith a heating/cooling changeover switch, if so do notremove it.• Remove the 4 torx screws (T20) and slide out the coiland drain pan assembly.• Replacement is by the reversal of the procedure des-cribed above. Ensure that all gaskets are changed (newgaskets fitted) and that the inlet and outlet connectionsto the coil are made correctly using an appropriatesealing compound applied to the valve body.• Bleed all air from the coil during refilling.ATTENTION: It is advisable to tighten the valve body tothe coils with caution (15 N·m is sufficient) to ensure theyare not damaged.4.2.2 - Coil inlet/outlet positions (fig. 15)Water inlets/outlets, sizes 1.9/2.9.Water inlets/outlets, size 4.9.ATTENTION: Carefully observe the direction indicatedby the arrow on the valves, based on the connection sideand the valve type.4.3 - Duct connection spigotsThese are manufactured from high density plastic with aVO fire rating. They are encased inside the unit. The ductsshould be fixed to these spigots using circular collars oradhesive. Screws and rivets should not be used.WARNING: In order to guarantee good air tightness, theduct should overlap the whole of the spigot.Make sure that the maximum supply air temperature doesnot exceed 60°C.Do not lift or support the unit using the spigots, place loadson the spigots or damage the spigots during installation oroperation.4.4 - Optional air filter and filter access: air filterreplacementAir filters should be changed regularly. How often this isneeded depends on the cleanliness of the working environ-ment and the rate at which the filter becomes clogged.If clogged filters are not changed they can increase thepressure drop, trapped dust particles may be given off andentrained in the air supply, and the general performance ofthe ICM may be degraded as the air flow reduces.NOTE: The condensate drain pan is located at the suctionend of the fan, and could therefore overflow if the airfilter became clogged. This is because the partial vacuuminside the unit could stop the condensate from drainingnormally.access from the side (fig. 1c)To access the filter, open the latch, open the hinged accessdoor and remove the filter from its housing by releasing thetwo clips which hold it in place.When replacing the filter, make sure that the sealing gasketis against the internal metal housing.access from above or below (figs. 1a and 1b)In these situations the filter is installed in a removableplug-in unit. To replace the filter assembly, disengage thetwo latches and withdraw the plug-in unit. Remove the oldfilter and insert a new one ensuring that the sealing gasketis against the internal metal housing.NOTE: When installing an ICM in a ceiling void, checkthat no T-bars will obstruct access to the filter or preventthe plug-in unit from being withdrawn.4.5 - Constant-volume fresh air controller4.5.1 - Constant-volume fresh air controllerThe 42BJ ICM can be fitted with a constant fresh air flowcontroller allowing the introduction of fresh air and the airchange rate to be controlled.The following range of fresh air controllers is available:option a: 8.3 l/s (30 m3/h) (-10%; +20%)option b: 16.6-44.4 l/s (60-160 m3/h) (-10%; +20%)options a and b: the diameter of the spigot housing thefresh air flow controller is 125 mm.The 16.6 1/s (60 m3/h) fresh air controller may be modifiedon site by relocating or removing two plastic restrictors inorder to increase the maximum constant fresh air flowcapacity to 44.4 1/s (160 m3/h). A label on the 42BJ ICMshows how to adjust the two plastic restrictors (Fig. 11).