Carrier 37HS Moduline Installation Instructions Manual

Also see for MODULINE 37HS: Installation instructions and parts list Application data Installation, Start-Up and Service Instructions

Contents

Carrier 37HS Moduline Installation Instructions Manual Manual pdf 30 page image

30Fig. 42 — Thermostat Level DetailNOTE: Maximum inlet pressure — 3.0-in. wg.START-UPPrinciples of OperationGENERALUnits are normally open (bellows deflated). Rise in bellowspressure closes unit. When thermostat is calling for no flow,pressure differences between unit plenum (measured at con-trol filter) and bellows should be less than 0.1-in. wg.A leak may cause bellows in circuit to be fully open, partiallyopen or fully closed depending on location of the leak.An obstruction prevents operation of all bellows down-stream. The inoperative bellows may remain open or closed,depending on whether air has been trapped in them.CONSTANT VOLUME OPERATIONBoth high-pressure and low-pressure control air from the ple-num of the master unit passes through the filter to the volumecontroller. An adjustable bleed orifice reacting to the relativechange of high and low pressure allows a set amount of con-trol air to pressurize the bellows until unit air delivery match-es the controller setting.VARIABLE AIR VOLUME OPERATIONThe constant volume control becomes variable volume con-trol with the addition of a thermostat. The thermostat enablesthe control to sense changes in the room temperature, over-ride the volume controller and reduce the unit flow to matchthe thermostat setting. If room temperature rises, the bellowswill bleed, increasing unit flow until the thermostat is satis-fied. If room temperature falls, the bellows will inflate, de-creasing the unit flow until the thermostat is satisfied.Preliminary System CheckPerform air balancing and control system checkout beforebuilding is occupied but after conditioned spaces are reason-ably clean. The high induction ratio of 37HS Moduline® dif-fusers can produce ceiling smudges within a few days if con-struction dirt is present.Before starting system, thoroughly check the air handling ap-paratus and controls. Verify that the fan static pressure controlis operating properly so that starting the fan without airflowat terminals will not cause duct damage from overpressure.1. Check fan and system controls for proper hookup.2. Be sure that all dampers, including fan inlet, fan outletand outdoor-air and return-air dampers, have proper free-dom of movement. Lubricate as required.3. Check fan belts, motors, sheave alignment and fan wheelrotation. Check bearings for proper lubrication. Refer tofan manufacturer’s recommendations.4. Be sure that fan final filters are in place. If not, accumu-lated dirt will be distributed throughout the system andcan accumulate in unit or fall into space. Dirt can alsodisrupt air terminal operation.5. Be sure that fan, coil, filter section and ductwork areclean and free of any construction debris.6. Remove protective tape from all diffusers.Initial Start-UpGENERAL CHECKOUT1. Start the variable volume air-supply system and obtainsuitable supply-air temperature and pressure. If designspeed of supply fan is based on a diversified block load,close zone fire dampers or set Moduline thermostats athighest setting to obtain sufficient pressure at terminalbeing balanced.2. Check the air terminal system for open control loops.Noise and excessive airflow at unit may indicate discon-nected tubes, loose plugs or fittings. Correct the problembefore beginning detailed checkout below.SERVICEGaining Access to Control AreaOn standard units, center diffuser is not removable. Removeceiling tile or reach through nearby light fixture to gain ac-cess to controls.Table 8 — Minimum Static Pressure at Control(Master) Unit - Units with System-Powered Controlsand Standard DiffusersAIRFLOW(cfm)37HS1 37HS2 37HS4PLENUM SIZE (in.)5 X 77 X 7 7 X 7 9 X 99 X 9 9 X 9 11 X 1111 X 11 11 X 11 13 X 13Minimum Static Pressure (in. wg.)405060700.75 0.75 — —80901000.75 0.75 0.75 —110 0.90 0.90 0.75 —120140 — — 0.75 —160180200— — 0.75 0.75220 — — 0.90 0.75240280320360400— — — 0.75440 — — — 0.90Table 9 — Minimum Airflow (cfm)MINIMUM AIRFLOW (cfm)37HS1 37HS2 37HS440 80 160THERMOSTATLEVERIN CEILING

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