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American Standard CH530 Figure 13. CDHE/F/G sequence of operation: lead 2 lag 1

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CDHF-SVU01C-EN

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General

Information

Fixed Sequence – Compressor 2 /

Compressor 1

If the chiller is in the Auto mode and

all interlocks have been satisfied,

compressor 2 will be started based

on the leaving water temperature

rising above the “Differential to Start”

setting. Compressors 1 will stage on

when the overall chiller average

capacity exceeds Stage on Load

point for 30 seconds. The stage on

load point is adjustable up to 50%.

The default is 40% which means that

a single compressor would have to

load to 80% (the average would be

40%) before the second compressor

starts. Both compressors will run

until chiller average capacity drops

below Stage off Load point for 30

seconds. The stage off load point is

also adjustable. Compressor 1 will

be shut down and compressor 2 will

run until water temperature drops

below the differential to stop. Before

shutting down, compressor 1 will be

unloaded and compressor 2 will be

loaded to maintain the same average

capacity command.

If chilled water reset is used, the

upstream compressor usually will be

the most efficient compressor to

operate at part load. If the leaving

water temperature is reset and the

chiller only needs one compressor,

then the upstream compressor

would be running closer to its

selection point and will be the most

efficient compressor to operate.

Figure 13. CDHE/F/G sequence of operation: lead 2 lag 1

Contents

Main Warnings and Cautions Contents Typical Product Description Block Unit Nameplate Literature change About this manual Page Page Commonly Used Acronyms Figure 1. General Duplex unit components - front view Page Cooling Cycle Page Page Page Figure 7. Sequence of operation overview. Figure 8. CDHE/F/G sequence of operation: auto to running Figure 9. CDHE, CDHF, and CDHG sequence of operation: running Page Figure 12. CDHF/G sequence of operation: lead 1/lag 2 Figure 13. CDHE/F/G sequence of operation: lead 2 lag 1 Figure 14. CDHF/G sequence of operation: equalize starts and hours Figure 15. CDHF/G sequence of operation: combined start Page Oil and Refrigerant Pump Surface Temperatures! Page Base Loading Control Algorithm: Page Ice Machine Control Figure 18. Sequence of operation: ice making: running to ice making Figure 19. Sequence of operation: ice making: stopped to ice to ice building complete Hot Water control Unit Control Panel (UCP) Control Panel Devices and Unit Mounted Devices Figure 20. Left control panel Unit Control Panel (UCP) Tracer CH530 Chiller Controller Figure 21. DynaView main processor Page Page A general description of the top level modes is show in the following table. Figure 22 Figure 23 Page Main Screen Data Fields Table Diagnostic Screen Page Page Report Menu Report name: System Evaporator Report name: Circuit Evaporator Report name: System Condenser Report name: Circuit Condenser Report name: System ASHRAE Chiller Log Report name: Circuit ASHRAE Chiller Log Historic Diagnostics Log Page Chiller Feature Settings System Mode Overrides Circuit Mode Overrides (0 to disable) Purge Display Settings { Page Page Page Page Control Panel Internally mounted devices Interprocessor Communication Inter Processor Communications IPC3 Page Page Control Panel Devices Head Relief Request Output Maximum Capacity Relay Compressor Running Relay Machine Shutdown Manual Reset (MMR) Chilled and Condenser Water Flow Interlock Circuits Refrigerant Monitor Input 1A17 Page CDRP Refrigerant Pressure Output Option 1A15: Figure 25. Condenser pressure based output Page GBAS (Generic Building Automation System) Figure 27. Voltage versus percent RLA External Chilled Water Setpoint (ECWS) External Current Limit Setpoint WPSR (WFC Water Pressure Sensing Option) Module Characteristics Page Recommended Length to Run external Output signals Unit mounted devices Page Page Electrical Sequence UCP and Wye-Delta Starter Control Circuits Page Page Figure 24. Test and start timing sequence Page Momentary Power Loss (MPL) Protection. and starter module remain powered) Figure 29. Sequence of operation: momentary power loss, (DynaView Current Overload Protection Figure 30. Overload trip time versus percent RLA Current Limit Protection Reverse Rotation Protection Differential to Start or Stop SoftLoading Evaporator Limit Leaving Water Temperature Cutout Low Refrigerant Temperature Cutout Page Condenser Limit Restart Inhibit Page Page Controls Chilled Water Reset (CWR) Return Water = Maximum Reset. Outdoor Air Temperature Where Constant Return Reset Ratio: Figure 32. Outdoor air temperature versus degrees of reset Page Page Page Unit Start-Up Procedures Unit Startup Seasonal Unit Start-Up Unit Startup Live Electrical Components! Toxic Hazards! Unit Shutdown Unit Shutdown Procedures Seasonal Unit Shutdown Oil Pump Heater Operation! Trouble Analysis Moisture Contamination! Hazardous Voltage w/Capacitors! Normal Chiller Operating Characteristics Weekly Maintenance Every 6 Months Every 3 Months Off-Season Maintenance Annual Maintenance Oil Maintenance Compressor Oil Change Oil Change Procedure Heater Damage! Oil Maintenance Replacing Oil Filter Other Maintenance Requirements Oil Supply System Problems! Hazardous Voltage w/ Capacitors! Figure 37. Rotary valve in drain position Refrigerant Charge Contains Refrigerant! Recovery and Recycle Connections Leak Testing Figure 38. Typical chemical cleaning setup Cleaning the Condenser Proper Water Treatment! Unit Corrosion Damage! Cleaning the Evaporator Control Settings and Adjustments Purge System Unit Preparation Contains Refrigerant! Live Electrical Components!