Sterling 30RA010-055 manual Deadband Multiplier

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Fig. 12 — Deadband Multiplier

MINUTES LEFT FOR START — This value is displayed only in the network display tables (using Service Tool, ComfortVIEW™ or ComfortWORKS® software) and represents the amount of time to elapse before the unit will start its initialization routine. This value can be zero without the machine running in many situations. This can include being unoccupied, ENABLE/OFF/REMOTE CONTACT switch in the OFF position, SCN not allowing unit to start, Demand Limit in effect, no call for cooling due to no load, and alarm or alert conditions present. If the machine should be running and none of the above are true, a minimum off time (DELY, see below) may be in effect. The machine should start normally once the time limit has expired.

MINUTES OFF TIME (DELY) [Configuration OPT2] — This user-configurable time period is used by the control to determine how long unit operation is delayed after power is applied/restored to the unit. Typically, this time period is con- figured when multiple machines are located on a single site. For example, this gives the user the ability to prevent all the units from restarting at once after a power failure. A value of zero for this variable does not mean that the unit should be running.

LEAD/LAG DETERMINATION — This is a configurable choice and is factory set to be automatic for all units. The value can be changed to Circuit A or Circuit B leading as desired. Set at automatic, the control will sum the current number of logged circuit starts and one-quarter of the current operating hours for each circuit. The circuit with the lowest sum is started first. Changes to which circuit is the lead circuit and which is the lag are also made when total machine capacity is at 100% or when there is a change in the direction of capacity (increase or decrease) and each circuit’s capacity is equal.

CAPACITY CONTROL OVERRIDES — The following over- rides will modify the normal operation of the routine.

Deadband Multiplier — The user configurable Deadband Multiplier (Z.GN) [Configuration, SLCT] has a default value of 1.0. The range is from 1.0 to 4.0. When set to other than 1.0, this factor is applied to the capacity Load/Unload Factor. The larger this value is set, the longer the control will delay between adding or removing stages of capacity. Figure 12 shows how compressor starts can be reduced over time if the leaving water temperature is allowed to drift a larger amount above and be- low the set point. This value should be set in the range of 3.0 to 4.0 for systems with small loop volumes.

First Stage Override — If the current capacity stage is zero, the control will modify the routine with a 1.2 factor on adding the first stage to reduce cycling. This factor is also applied when the control is attempting to remove the last stage of capacity.

Slow Change Override — The control prevents the capacity stages from being changed when the leaving fluid temperature is close to the set point (within an adjustable deadband) and moving towards the set point.

Ramp Loading (CRMP) [Configuration, SLCT] — Limits the rate of change of leaving fluid temperature. If the unit is in a Cooling mode and configured for Ramp Loading, the control makes 2 comparisons before deciding to change stages of ca- pacity. The control calculates a temperature difference between the control point and leaving fluid temperature. If the differ- ence is greater than 4 °F (2.2 °C) and the rate of change (°F or °C per minute) is more than the configured Cooling Ramp Loading value (CRMP), the control does not allow any chang- es to the current stage of capacity.

Low Entering Fluid Temperature Unloading — When the entering fluid temperature is below the control point, the control will attempt to remove 25% of the current stages being used. If exactly 25% cannot be removed, the control removes an amount greater than 25% but no more than necessary. The lowest stage will not be removed.

Minimum Load Control — If equipped, the minimum load control valve is energized only when one compressor in the circuit is running. If the close control feature is enabled the minimum load control valve may be used as needed to obtain leaving fluid temperature close to set point.

Cooler Freeze Protection — The control will try to prevent shutting the chiller down on a Cooler Freeze Protection alarm by removing stages of capacity. If the cooler fluid selected is Water, the freeze point is 34 F (1.1 C). If the cooler fluid selected is Brine, the freeze point is the Brine freeze Point (BR.FZ) [Set Points, FRZ]. This alarm condition (A207) only references leaving fluid temperature and NOT Brine Freeze point. If the cooler leaving fluid temperature is less than the freeze point plus 2.0° F (1.1° C), the control will immediately remove one stage of capacity. This can be repeated once every 30 seconds.

Low Saturated Suction Protection — The control will try to prevent shutting a circuit down due to low saturated suction conditions by removing stages of capacity. These circuit alert conditions (T116, T117) compare saturated suction tempera- ture to the configured Brine Freeze point (BR.FZ) [Set Points, FRZ]. The Brine Freeze point is a user-configurable value that must be left at 34 F (1.1 C) for 100% water systems. A lower value may be entered for systems with brine solutions, but this value should be set according to the freeze protection level of the brine mixture. Failure to properly set this brine freeze point value may permanently damage the brazed plate heat exchang- er. The control will initiate Mode 7 (Circuit A) or Mode 8 (Cir- cuit B) to indicate a circuit’s capacity is limited and that even- tually the circuit may shut down.

 

 

 

 

 

DEADBAND EXAMPLE

 

2 STARTS

 

 

 

 

 

 

 

 

 

 

47

 

 

 

 

 

 

8

 

46

 

 

 

 

 

 

 

 

 

 

 

 

 

(C)

7

 

45

 

 

 

 

 

(F)

 

 

 

 

 

 

 

44

 

 

 

 

 

LWT

 

LWT

 

 

 

 

 

6

43

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

42

 

 

 

 

 

 

5

 

41

 

 

 

 

 

 

 

 

0

200

400

600

800

1000

 

 

 

 

 

TIME (SECONDS)

 

3 STARTS

 

 

 

 

STANDARD

 

 

 

 

LEGEND

 

 

 

DEADBAND

 

 

MODIFIED

LWT — Leaving Water Temperature

 

 

 

 

 

 

DEADBAND

Fig. 12 — Deadband Multiplier

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Contents SAFETY CONSIDERATIONS CONTENTS GENERALMAJOR SYSTEM COMPONENTS Control Module CommunicationSterlco Comfort Network SCN Interface — Table 1 — Unit SizesTable 3 — Status Switches Table 5 - SCN Communication Bus WiringTable 2 — Thermistor Designations Table 4 - Output RelaysLEGEND FOR FIG. Page Page Fig. 3 — Wiring Schematic 30RA010-018 30RA010-018AQUA SNAPSEE NOTE SEE NOTE AQUA-SNAPLOW VOLTAGE CONTROL SCHEMATICFig. 3 - Wiring Schematic 30RA010-018cont Fig. 4 - Wiring Schematic 30RA022-030 30RA022-030AQUA SNAPFig. 4 - Wiring Schematic 30RA022-030cont AQUA-SNAPLOW VOLTAGE CONTROL SCHEMATICFig. 5 — Wiring Schematic 30RA032-040 30RA032-040AQUA SNAPFig. 5 — Wiring Schematic 30RA032-040cont AQUA-SNAPLOW VOLTAGE CONTROL SCHEMATICFig. 6 — Wiring Schematic 30RA042-055 30RA042-055AQUA SNAPFig. 6 — Wiring Schematic 30RA042-055cont AQUA-SNAPLOW VOLTAGE CONTROL SCHEMATICFig. 7 — Main Base Board ESCAPEENTERREMOTE CONTACT SW1 OFF ENABLE OFF SW2 ON MODEFig. 9 — Typical Space Temperature Sensor Wiring Fig. 11 - Energy Management Module CEPL130351100/100 Fig. 12 — Deadband Multiplier Fig. 14 — 30RA Condenser Fan Sequence Fig. 13 — Operating Envelope forR-22Maneurop Compressor Cooling Set Point Select Service Test See Table 11 — Both main power and control circuit power must be onTable 8 — Control Methods and Cooling Set Points Fig. 16 — Scrolling Marquee DisplayOptional Factory-InstalledHydronic Package — •Cooler Pump Control CPC Configuration, OPT1 ON Fig. 17 — Dual Chiller Thermistor Location Table 9 — Marquee Display Menu StructureTable 10 — Run Status Mode and Sub-ModeDirectory SUB-MODE Table 12 - Temperature Mode and Sub-ModeDirectory Table 15 — Inputs Mode and Sub-ModeDirectory Table 13 — Pressure Mode and Sub-ModeDirectoryTable 14 — Set Point and Sub-ModeDirectory Table 16 — Outputs Mode and Sub-ModeDirectory SUB-MODEKEYPAD DISPLAYSUB-MODE KEYPADITEM DISPLAYSUB-MODE KEYPADITEM DISPLAYTable 18 — Time Clock Mode and Sub-ModeDirectory PER.3 SUB-MODE Table 20 — Alarms Mode and Sub-ModeDirectory Table 19 — Operating Mode and Sub-ModeDirectorySUB-MODE ITEMKEYPAD ENTRY DISPLAYRSET DISP Table 23 — Operating Modes Table 24 — Example of Reading and Clearing Alarms Table 25A — 4-20mA ResetTable 26B — Configuring Return Temperature Reset Fig. 18 — Standard Chilled Fluid Temperature Control — No ResetFig. 19 — Outdoor-AirTemperature Reset Fig. 20 — Space Temperature ResetFig. 21A — 4- to 20-mADemand Limiting Fig. 21B — Cooling Set Point 4 to 20 mATROUBLESHOOTING Table 27 — Configuring Demand Limitand fluid tubing Table 28 — TroubleshootingRecommended that system be filled with an appro Fig. 22 — Component Arrangement — 30RA010-030 FU — Fuse GND — GroundFig. 23 — Component Arrangement — 30RA032-040 FU — Fuse GND — GroundFig. 24 — Component Arrangement — 30RA042-055 FU — Fuse GND — GroundNOTES LEGEND Table 29 — Alarm and Alert Codes Table 29 - Alarm and Alert Codes cont Table 29 — Alarm and Alert Codes cont ALARMTable 29 — Alarm and Alert Codes cont ALARMTable 29 — Alarm and Alert Codes cont ALARMSERVICE Compressor Replacement Refer to FigTable 30 - Unit Torque Specification Electronic ComponentsFig. 28 — Compressor Wiring Fig. 27 — Typical Compressor Mounting — All SizesFig. 29 — Compressor Location — 30RA010-030 Fig. 30 — Compressor Location — 30RA032-055Condenser Section and Coils Table 31 - Oil ChargeFig. 31 — 30RA Access Panels Check Refrigerant Feed ComponentsFig. 32 — Condenser-FanMounting Fig. 33 — Condenser-FanPosition Standard FanTable 32 — Factory Settings, High-Pressure Switch FixedCompressor and Unit Protective Devices Check Unit SafetiesCOOLER FREEZE-UPPROTECTION TEMP TEMP For Thermistor T10 For Thermistor T10 Fig. 36 — Thermistor Connections to Main Base Board, J8 ConnectorFig. 35 — Fluid-SideTemperature Sensors T1 and T2 PROGRAMMING Mode •P51: SOFTWARE version Table 37 - Fault Codes•P50: FAULT HISTORY — Last 8 faults PARAMETERS Table 39 — Replacement Modules MAINTENANCE Minimum Loop VolumePRE-START-UP System CheckOperating Limitations Standard 30RA Units OPERATION SEQUENCETable 41 — Temperature Limits for APPENDIX A SCN Tables A_UNIT General Unit ParametersCIRCADIO Circuit A Discrete Inputs/Outputs CIRCA_AN Circuit A Analog ParametersOPTIONS Unit Parameters CIRCBDIO Circuit B Discrete Inputs/OutputsCIRCB_AN Circuit B Analog Parameters ALARMDEF Alarm Definition Table DISPLAY Marquee Display SETUPDUALCHIL Dual Chiller Configuration Settings BRODEFS Broadcast POC Definition TableOPTIONS1 Options 1 Configuration OPTIONS2 Options 2 ConfigurationSETPOINT SCHEDOVR Timed Override SetupRESETCON Temperature Reset and Demand Limit MAINTENANCE ALARMS: Maintenance DisplayUNIT CURRMODS: Maintenance Display DUALCHIL: Maintenance DisplayLEARNFNS Maintenance Display LOADFACT: Maintenance DisplayPM-STRN Maintenance Display PM-COIL:Maintenance DisplayPM-PUMP:Maintenance Display RUNTEST: Maintenance Display VERSIONS: Maintenance Display STRTHOUR Maintenance DisplayTESTMODE: Maintenance Display WSMDEFME: Maintenance Display AND MANUAL STARTERS FACTORY SETTINGS FOR COMPRESSOR, FAN, PUMPAPPENDIX B AND MANUAL STARTERS cont FACTORY SETTINGS FOR COMPRESSOR, FAN, PUMPAPPENDIX C DataPort, DataLink, BAClink Object DefinitionOPTIONS SETPOINTSTART-UPCHECKLIST FOR 30RA LIQUID CHILLER Remove and use for Job File I.Project InformationII. Preliminary Equipment Check Design InformationIII. Unit Start-Up Start and Operate Machine. Complete the FollowingCL-3 CL-4 Record Software Versions MODE — RUN STATUSCOMMENTS III.Unit Start-Upcont UNIT Configuration SettingsOPTIONS1 Options Configuration OPTIONS2 Options Configuration RSET Reset Configuration SettingsIII.Unit Start-Upcont CL-6SLCT Setpoint and Ramp Load Configuration III.Unit Start-UpcontSETPOINT CL-7Service Test Mode and Sub-ModeDirectory III.Unit Start-Upcont
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