Manuals / Carrier / Household Appliance / Air Conditioner

Carrier 37HS specifications Controller Shut Off, Unit Shut Off

Models: 37HS

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Controller Shut Off, Unit Shut Off

Fig. 58 Ð Variable Volume Controls Ð Thermostat Open,

Controller Shut Off, Unit Shut Off

VAV COOLING WITH WARM-UP Ð Including the warm- fup switch in the volume controller/thermostat circuit al- lows the unit to deliver air when there is warm air in the duct system, even though the cooling thermostat is satis®ed by cool space temperature.

The warm-up switch is actually a temperature controlled pneumatic valve which is normally open at primary air sup- ply temperatures below approximately 64 F. It is installed in-line between the volume controller and the thermostat.

When warm primary air is supplied to restore comfort con- ditions in the space after an extended shutdown, the warm-up switch reacts by closing (Fig. 59). This removes the ther- mostat from the control circuit and prevents air from bleed- ing from the low pressure chamber of the volume controller. This condition simulates a thermostat calling for maximum primary-air delivery. The unit is now, in effect, a CV unit and operates at the set point of the volume controller. This

condition will continue as long as air in the duct system re- mains at a temperature higher than approximately 80 F. As the supply air returns to normal cooling temperatures, the switch opens and control is returned to the cooling thermo- stat. See Fig. 60.

Because the units are shut off, it may be difficult to es- tablish the ¯ow of warm air to initiate warm-up. One method of overcoming this problem is to install one or more CV units near the end of the duct run. Where possible, a constant vol- ume unit is located in space not continuously occupied such as halls, aisles, or storage rooms. It can also be helpful in an area bene®ting from continuous circulation. By locating such a unit at the end of a duct run, the heated air for morning warm-up is assured of reaching the VAV units. See Fig. 61.

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Carrier 37HS specifications Controller Shut Off, Unit Shut Off

Contents

System-PoweredControls With 37HS Moduline Air TerminalsStep 1 Ð Determine Air Volume Cfm System-PoweredControls WithBUILDING LOAD CALCULATION Fig. 2 Ð 37HS Unit With VAV ControlsFig. 4 Ð Floor Plan of Typical Zones Fig. 3 Ð Estimating Block Loadfor Single-StoryOffice Building DESIGN PROCEDURE with example Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page ·Baseboard ·Overhead air Fig. 5 Ð Separate Duct Heating System Fig. 6 Ð 35BD Heating Slot Boot DiffuserPerformance Heating Ð Downblow Slot Fig. 7 Ð Director Diffuser Table 1 Ð Optimum Outlet Discharge TERMINAL SELECTION AND LAYOUTTable 2 Ð Location Guidelines Fig. 10 Ð Moduline Units in Air Series Fig. 9 Ð Single Moduline Unit Connected toSupply Duct Fig. 11 Ð Master Unit and Slave UnitsFig. 14 Ð Diffuser Locations for Step 2 Ð Lay Out TerminalsTable 3 Ð Recommended Maximum Cfm Per Terminal Preferred 2-Wayor One-WayBlow1-Wayand 2-WayBlow, 2-SlotDiffusers Fig. 16 Ð Locate Units to Prevent Down-DraftsTable 4 Ð Air Throw Data Ð Table 5 Ð Air Throw Data ÐFig. 17 Ð Staggered Units Step 3 Ð Consider Unit Combinations And RunFig. 18 Ð Unit Spacing Fig. 19 Ð Run-OutDuct for Single Moduline Unit Table 6 Ð 37HS1 Units in Air Series Table 6 Ð 37HS1 Units in Air Series cont Table 7 Ð 37HS2 Units in Air Series Table 7 Ð 37HS2 Units in Air Series cont Table 8 Ð 37HS4 Units in Air SeriesTable 8 Ð 37HS4 Units in Air Series cont Table 9 Ð Maximum Cfm Through the Inlet Collar of a Single Unit or of Units in Air Series0.97+ 0.16 = 1.13 in. wg Controls and Standard Diffusers Master Unit Ð Units with System-PoweredTable 10 Ð Minimum Static Pressure at Control Fig. 23 Ð Three 37HS2 ModulineAir Series on One Controller Fig. 25 Ð Flexible Duct Used with 90-DegreeBendTable 13 Ð Maximum Number of Units in an Fig. 26 Ð Air Intake on Master UnitFig. 27 Ð Location of Volume Controller on Single UnitPage The corrected layout Fig. 30 Ð Corrected LayoutFig. 31 Ð Control Tubing Connection 1.Room A has its own controllerTHE MODULINE VALVE UNIT MODULATING Ð BELLOWS PARTIALLY INFLATED Fig. 32 Ð Bellows and Unit Air Valve ArrangementUNIT SHUTOFF Ð BELLOWS FULLY INFLATED UNIT FULL CAPACITY Ð BELLOWS DEFLATEDFig. 33 Ð Cross Section of 37HS Moduline Air Terminal Fig. 34 Ð Bellows ComparisonCONTROL APPLICATIONS System-PoweredControlsFig. 35 Ð High and Low Pressure Pick-UpTubes Fig. 36 Ð 37HS Control Components Fig. 37 Ð Basic 37HS Control OperationFig. 41 Ð Wall-MountedThermostat Fig. 39 Ð 37HS Air¯ow Volume ControllerFig. 42 Ð Diffuser Baffle Assembly Fig. 38 Ð 37HS Control Filter/ManifoldFig. 44 Ð Variable Air Volume Control Arrangement Fig. 43 Ð Constant Volume Control ArrangementSystem-Powered Warm-Up Fig. 45 Ð VAV Control Arrangement forFig. 49 Ð VAV Control Arrangement Fig. 47 Ð Cooling/Heating Wall ThermostatFig. 48 Ð Wall-MountedHeating Thermostat for Electric Warm-UpElectric Heat Interlock Pneumatic Warm-UpSwitchFig. 51 Ð VAV Control Arrangement with Fig. 52 Ð Pilot Valve for Pneumatic SequencedCONTROL SELECTION Table 14 Ð Control IndexTable 15 Ð 37HS Control Combinations Table 15 Ð 37HS Control Combinations cont Table 15 Ð 37HS Control Combinations cont CONTROLTable 15 Ð 37HS Control Combinations cont CONTROLSystem-PoweredControls CONTROL OPERATING SEQUENCESFig. 55 Ð Variable Volume Controls Schematic Unit Supplying Air Controller Shut Off, Unit Shut Off Controller Bleeding, Unit Heating VAV HEATING AND COOLING WITH SYSTEM- POWERED CHANGEOVER Ð This application uses a CV control package along with a wall-mountedthermostat pack- age cooling/heating and a system-poweredchangeover con- trol package. The cooling thermostat is direct acting DA while the heating thermostat is reverse acting RA Fig. 62 Ð Heating/Cooling Unit Ð Cooling, Cold Air in Duct, Changeover in Cooling Fig. 64 Ð Heating/Cooling Unit Ð Cooling, Cold Air in Duct, Changeover in Cooling VAV HEATING Ð It is suggested that the following section be reviewed before reading this section: VAV Cooling, page System-PoweredControls with Electric Interface Controller Bleeding, Unit Heating VAV HEATING AND COOLING WITH ELECTRIC CHANGEOVER Ð This application uses a CV control pack- age along with a wall-mountedthermostat package cooling/ heating and an electric changeover package. The change- over valve permits control of the unit to be switched between the cooling and heating sides of a cooling/heating thermo- stat. It is eld-installed in-linebetween the volume control- ler and the thermostat Fig. 71 Ð Heating/Cooling Unit Ð Heating, Hot Air in Duct, Electric Changeover in Heating Fig. 74 Ð Connection for Electric Interlock Fig. 77 Ð Piping Diagram, Heating/Cooling Fig. 75 Ð Piping Diagram, Heating/CoolingFig. 76 Ð Sequence Diagram Ð DA Thermostat Fig. 78 Ð Sequence Diagram, RA ThermostatFig. 81 Ð Piping Diagram, NC Conguration Fig. 79 Ð Piping Diagram, NO CongurationWarm-UpSwitch LEGEND FOR FIG. 79 -AIRFLOW ADJUSTMENT HK08ZZ030 CFMTable 17 Ð Multiple Unit Air¯ow Variation AIR DISTRIBUTION Fig. 86 Ð Typical Room Air Distribution Pattern 37HS Ð 2-WAYBLOW 37HS2 Ð ONE-WAYBLOWPage Table 18 Ð Standard Diffusers for 37HS1 Table 19 Ð Standard Diffusers for 37HS2 Table 20 Ð Standard Diffusers for 37HS4 Table 21 Ð Optional Diffusers for 37HS1 Table 22 Ð Optional Diffusers for 37HS2 Table 23 Ð Optional Diffusers for 37HS4 Table 25 Ð Air Throw Data Ð Table 24 Ð Air Throw Data Ð1-Wayand 2-WayBlow, 2-SlotDiffusers 2-Wayand 1-WayDirector, 3-SlotDiffusersPage Copyright 1991 Carrier Corporation