Carrier 40MBD Product Data

Also see for 38MAQ Series: Service manual Owner's manual Owner's manual Owner's manual

Contents

12APPLICATION DATAUNIT SELECTIONSelect equipment to either match or be slightly less than anticipatedpeak load. This provides better humidity control, fewer unit cycles,and less part- load operation.For units used in spaces with high sensible loads, base equipmentselection on unit sensible load, not on total anticipated load. Adjustfor anticipated room wet bulb temperature to avoid undersizingequipment.UNIT MOUNTING (INDOOR)Refer to unit Installation Instructions for further details.Unit leveling - For reliable operation, units should be level in allplanes.Clearance - Provide adequate clearance for airflow as shown inFig. 3.Unit location - Select a location which will provide the best aircirculation for the room.These units should be positioned as accessible as possible abovethe ceiling. The unit return and discharge should not be obstructedby furniture, curtains, or anything which may cause unit shortcycling or air recirculation. Duct the unit in the middle of theselected wall (if possible). Duct towards an outside wall, ifavailable, to make piping easier, and place the unit so it faces thenormal location of room occupants.UNIT MOUNTING (OUTDOOR)Refer to unit Installation Instructions for further details.Unit leveling - For reliable operation, units should be level in allplanes.Clearance - Minimum clearance, as shown in Fig. 5, must beprovided for airflow. The condensing units are designed forfree- blow application. Air inlets and outlets should not berestricted.Unit location - A location which is convenient to installation andnot exposed to strong wind.A location which can bear the weight of outdoor unit and wherethe outdoor unit can be mounted in a level position.Do not install the indoor or outdoor units in a location with specialenvironmental conditions. For those applications, contact yourCarrier representative.MOUNTINGRefer to unit Installation Instructions for further details.SUPPORTAdequate support must be provided to support the weight of all fancoils. Refer to the Physical Data section for fan coil weights, andthe base unit dimensional drawings for the location of mountingbrackets.SYSTEM OPERATING CONDITIONSOperating RangeMin / Max °F (°C)Cooling HeatingOutdoor DB 4 / 122 (-20 / 50) 4 / 86 (-20 / 30)Indoor DB 63 / 90 (17 / 32) 32 / 86 (0 / 30)Indoor WB 59 / 84 (15 / 29)Non-Operating Temperature RangeMin / Max °F (°C)Indoor/Outdoor DB 32 / 86 (0 / 30)NOTE: Reference the Product Installation Instructions for moreinformation.METERING DEVICESThe outdoor unit (Sizes 09, 12, 18, 36 & 48) has an electronicexpansion valve to manage the refrigerant flow of the fan coilconnected. Size 24 has capillary tube metering devices in theoutdoor unit.DRAIN CONNECTIONSInstall drains to meet local sanitation codes. Standard ducted fancoil unit condensate pumps have a maximum lift of 29.5in(750mm).REFRIGERANT LINESGeneral refrigerant line sizing:1. The 38MAQ & 38MBQ units are shipped with a fullcharge of R410A refrigerant. All charges, line sizing, andcapacities are based on runs of 25 ft (7.6 m). For runs over25 ft (7.6 m), consult long- line section on this page forproper charge adjustments.2. Refrigerant lines should not be buried in the ground. If it isnecessary to bury the lines, not more than 36- in (914 mm)should be buried. Provide a minimum 6- in (152 mm)vertical rise to the service valves to prevent refrigerantmigration.3. Both lines must be insulated. Use a minimum of 1/2- in.(12.7 mm) thick insulation. Closed- cell insulation isrecommended in all long- line applications.4. Special consideration should be given to isolatinginterconnecting tubing from the building structure. Isolatethe tubing so that vibration or noise is not transmitted intothe structure.Long Line Applications, 38MAQ & 38MBQ Units:1. No change in line sizing is required.2. Add refrigerant per table below.ADDITIONAL CHARGE TABLEUnitSizeTotal LineLength ft Additional Charge, oz/ft. Ft (m)Min Max 10-25(3-8)>25-82(8-25)>82-98(25-30)>98-213(30-65)91082None0.271218 980.43 0.432436 213 0.4348