Carrier 42BJ MCI LEC Installation Instructions Manual

Contents

Carrier 42BJ MCI LEC Installation Instructions Manual Manual pdf 11 page image

11level the unit (figs. 7 and 8)Adjust the hanger nuts so that the unit is inclined 0.5%towards the condensate drain pan. In the other direction(air flow direction) the unit must be perfectly level (Fig. 8).Condensate drain pipe (Fig. 9): Use a flexible pipe with aninside diameter of 16 mm and provide a constant fall of 20mm/m over the whole horizontal pipe run. Install a 50 mm(minimum) siphon to prevent gases and odours from flowingback into the ceiling void.If several units are connected to a common collector, a devicemust be installed (Fig. 10). Before operating the unit, ensurethat the water flows into the internal condensate drain pan bypouring some water into it. If problems are detected, checkthe drain pipe slope and look for possible obstructions. Inall cases the connection duct(s) at the unit outlet must beinsulated to prevent any condensate formation on the walls.NOTE: The pressure losses of these ducts must be compa-tible with the unit performance. The duct must be as smoothas possible. Avoid sharp bends. Check that there are noleaks or kinks, and that there is no dirt or installationdebris inside the ducts. Debris within the ducts mightdamage the fan wheel and the damper in the air diffusers.When installation is complete - i.e. when the 42BJ is attachedto the ceiling, air ducts are complete, water manifolds arein position with stop valves ready on the connection stubs,and electrical installation is prepared - then connect thewater pipes (Carrier recommends the use of flexible waterpipes that can be supplied as an accessory). Each flexiblepipe has a 1/2" gas screw connector, depending on themodel. Ensure that a gasket (not supplied by Carrier) isinstalled between the screw connector and the stop valve.When all units are installed, open the stop valves on themanifolds, bleed and then pressurize the circuits. To bleedthe coils, remove the plastic plugs on the coil access doorand then slightly undo the bleed screws with a screwdriver.Close the valve firmly when all air has escaped.NOTE: Do not switch on the power until all connectionsare made and earthed.3.3 - Removal procedureSwitch off the unit power supply at the isolator providedfor the purpose during installation (isolator not suppliedby Carrier).• Disconnect the power supply and connection cables.• Close the isolating valves on the manifolds.• Disconnect the flexible water pipes by unscrewing thegas connectors.WARNING: Since the flexible water pipes do not havedrain valves, a receiver must be provided to allow thecooling coil to be drained.• Disconnect the supply and return air ducts.• Disconnect the flexible condensate drain pipe. Drainthe siphon into a suitable vessel.• Support the unit lightly and release it by unscrewingthe four nuts on the threaded hangers. Lower the unitcarefully.4 - COMPONENTS4.1 - Fan motor assembly4.1.1 - descriptionThe ICM has a double inlet high static pressure fan motorassembly.The low energy consumption motor uses a 230 V ± 10%,50 Hz single-phase power supply and runs at variable speedunder the control of a Carrier numeric controller supplying0-10 V control signal.4.1.2 - fan motor assembly removal procedureWARNING: Disconnect the power supply to the unit beforecarrying out any work on the unit.If the fan develops a fault the whole assembly must beremoved and replaced.• Remove the fan access panel (12a).• Disconnect the fan motor assembly power supplycables equipped with quick connectors (power andcontrol wiring).• Disconnect the electric heater supply cable from the42BJ. The cable has three wires terminating in flatspade connectors.• The fan motor and its support are held in place by onescrew (12b) and three lugs. Remove this screw andslide the assembly free of the lugs.• Remove the fan from its support panel (4 screws - 12c).• Replace the fan motor assembly and follow theprocedure in reverse order.WARNING: To reconnect the motor cables separate thepower wiring cable from the control wiring cable andpull them apart as far as possible.