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Carrier 37HS specifications System-PoweredControls with Electric Interface

Models: 37HS

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System-Powered Controls with Electric Interface

Fig. 67 Ð Variable Volume Controls Ð Minimum Flow: Thermostat Partially Open,

Controller Partially Open, Unit Delivering Minimum Flow

System-Powered Controls with Electric Interface

VAV COOLING WITH ELECTRIC WARM-UP Ð Another approach to warm-up is the addition of an electric warm-up valve; the operating principle is the same as system powered warm-up. A building with its conditioning system shut down during unoccupied hours must be brought close to operating temperature before the occupants arrive. Heated air supplied to the space from a central unit can quickly restore operating conditions. But because the VAV thermostat has closed the unit, the result of the lack of load, the system powered con- trol needs to be overcome.

An electric warm-up valve located on the Moduline unit between the volume controller and the thermostat is wired to the primary air source machine room. The valve can be activated by a simple manual or timer switch or it can

be connected to the warm-up terminal of the central station unit, if such is provided. Thus, when heated air be- gins to ¯ow in the distribution duct, the bellows is bled down by the action of the electric warm-up valve and heated air can ¯ow into the conditioned space (Fig. 68).

In the cooling mode (Fig. 69), air ¯ows freely between the volume controller and the thermostat and control func- tion is not affected. When warm-up is activated, the nor- mally open port closes and the control circuit is closed after the volume controller. As with system powered warm-up, this causes the pressure to rise in the low pressure chamber of the volume controller and opens the valve that bleeds air from the bellows pressure chamber. The increased bleed rate lowers the bellows pressure, opening the unit damper, and allowing the ¯ow of primary air to increase up to the con- stant volume set point of the volume controller.

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Carrier 37HS specifications System-PoweredControls with Electric Interface

Contents

37HS Moduline Air Terminals Step 1 Ð Determine Air Volume CfmSystem-PoweredControls With 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. 9 Ð Single Moduline Unit Connected to Supply DuctFig. 10 Ð Moduline Units in Air Series Fig. 11 Ð Master Unit and Slave UnitsStep 2 Ð Lay Out Terminals Table 3 Ð Recommended Maximum Cfm Per TerminalFig. 14 Ð Diffuser Locations for Preferred 2-Wayor One-WayBlowFig. 16 Ð Locate Units to Prevent Down-Drafts Table 4 Ð Air Throw Data Ð1-Wayand 2-WayBlow, 2-SlotDiffusers 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 Master Unit Ð Units with System-Powered Table 10 Ð Minimum Static Pressure at ControlControls and Standard Diffusers Fig. 23 Ð Three 37HS2 ModulineFig. 25 Ð Flexible Duct Used with 90-DegreeBend Table 13 Ð Maximum Number of Units in anAir Series on One Controller Fig. 26 Ð Air Intake on Master UnitFig. 27 Ð Location of Volume Controller on Single UnitPage Fig. 30 Ð Corrected Layout Fig. 31 Ð Control Tubing ConnectionThe corrected layout 1.Room A has its own controllerTHE MODULINE VALVE Fig. 32 Ð Bellows and Unit Air Valve Arrangement UNIT SHUTOFF Ð BELLOWS FULLY INFLATEDUNIT MODULATING Ð BELLOWS PARTIALLY 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. 39 Ð 37HS Air¯ow Volume Controller Fig. 42 Ð Diffuser Baffle AssemblyFig. 41 Ð Wall-MountedThermostat Fig. 38 Ð 37HS Control Filter/ManifoldFig. 43 Ð Constant Volume Control Arrangement System-Powered Warm-UpFig. 44 Ð Variable Air Volume Control Arrangement Fig. 45 Ð VAV Control Arrangement forFig. 47 Ð Cooling/Heating Wall Thermostat Fig. 48 Ð Wall-MountedHeating ThermostatFig. 49 Ð VAV Control Arrangement for Electric Warm-UpPneumatic Warm-UpSwitch Fig. 51 Ð VAV Control Arrangement withElectric Heat Interlock 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. 75 Ð Piping Diagram, Heating/Cooling Fig. 76 Ð Sequence Diagram Ð DA ThermostatFig. 77 Ð Piping Diagram, Heating/Cooling Fig. 78 Ð Sequence Diagram, RA ThermostatFig. 79 Ð Piping Diagram, NO Conguration Warm-UpSwitchFig. 81 Ð Piping Diagram, NC Conguration 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 24 Ð Air Throw Data Ð 1-Wayand 2-WayBlow, 2-SlotDiffusersTable 25 Ð Air Throw Data Ð 2-Wayand 1-WayDirector, 3-SlotDiffusersPage Copyright 1991 Carrier Corporation