Emerson iCOM user manual Second cooling source and compressorized cooling

Page 28

Operation

The Value setting is the factory default setting on free-cooling and dual cooling units. If the tempera- ture difference between the second source cooling fluid parameter, Free-cooling Fluid Temperature (User Menu, Sensor Data) and room air is equal to or greater than the adjustable DT Between Room Air / FC Fluid (Service Menu, Setpoints) value, then the second source cooling fluid will be used to provide at least partial cooling (delta T between room and glycol = true).

Sensors used for this delta T are: room/local sensor or the return air sensor; and the glycol sensor. If this delta T is true, the following actions will be performed:

1.The Free-Cooling Status indication will show “On” instead of “Off”.

2.The compressor band will be shifted to the right by 100%, and within the first 100% the free- cooling valve band will take place (see Figure 18).

Figure 18 Second cooling source and compressorized cooling

Temp Setpoint: 70°F

Proportional Band: 8°F

Deadband: 2°F

Valve	Valve 100%	Cool 1	Cool 2
Closed	Open	On	On
	+ 100%
½ Dead-	Cooling
½ Dead-

band

2ndComp Source

70

71

72

73

74

75

76

77

78

79

0% Cooling

	½ Proportional Band	½ Proportional Band	+ 200%
	Band1: 2nd Source	Band 2: Compressors
			Cooling

Increasing Temperature

Minimum Chilled Water Temperature—This feature permits the user to select the minimum chilled water temperature that allows simultaneous operation of the second cooling source (chilled water control) and compressor control. This feature is enabled in the Service menu under Setpoints, parameter Minimum CW Temp.

Below this minimum chilled water setpoint, parameter Minimum CW Temp Value, (Service Menu, Setpoints), the control will operate ONLY the second cooling source control, i.e., the compressor is locked out. Above the minimum chilled water setpoint, assuming the fluid temperature is below the return room air temperature (delta T between room and glycol = true), the control will operate the second cooling source control and compressor control simultaneously if needed.

If the Minimum CW Temp is disabled, the second cooling source temperature is ignored, the control will always operate the second cooling source and compressors simultaneously when the load requires it.

22

Image 28

Contents Liebert iCOM Page Table of Contents Teamwork Installing a Liebert Icom UNIT-TO-UNITNETWORKMounting a Large Display on a Wall Figures Tables Features Large and Small DisplaysESC Keyboard icons and functions Icon Key Name FunctionStatus menu, large display, graphical view Accessing Submenus Accessing Submenus on Small DisplaysAccessing Submenus on Large Displays Navigating Through the Liebert iCOM MenusEntering a Password Menu tree-Small display, stand-alone or networkedStatus Menu System View Status Menu Unit 1 View User Menu Service Menu UnitAdvanced Menu Unit Viewing Multiple Units with a Networked Large Display Service Menu Unit #Advanced Menu Unit # SET User menu icons Service menu icons Single Unit Functions Unit/Fan Control Start StopLoss of Power Alarm Fan Alarm / Fan Protection SettingsVSD Setpoint VSD Fan Speed Setting AutorestartHigh Pressure Alarm Pump DownCompressor Timing-Units With Two Compressors Digital Scroll High TemperatureCompressor Sequencing Motorized Ball Valve in Digital Scroll Units Service Offset-Changing System Pressure SettingsMBV Operation After Compressor is Turned Off Temperature Proportional Band Temperature proportional bandCompressor Control Compressor Proportional BandsOne Single-Step Compressor Without Unloaders-One-Step Two Single-Step Compressors Without Unloaders-Two-StepTwo Compressors With Unloaders-Four-Step Two compressors with unloaders four-stepDigital Scroll Compressors Digital scroll capacity modulation, 10-100% variableTemperature Control-Second Cooling Source Differential Temperatures / Controls Comparator CircuitDelta T Temperature Difference Between Room and Glycol Chilled Water ControlSecond cooling source and compressorized cooling Temperature Control-Reheat Reheat configuration typesGlycool Cooling-Free-Cooling Dual Cooling SourceOff ½ Proportional Band Decreasing Temperature Heat On ½ Dead Band 100%Tight Mode SCR ReheatStandard Mode Humidification Dehumidification Humidity ControlHumidification Parameters for infrared humidifier control Humidification Infrared HumidifierExternal Humidifier Control-Optional Dehumidification With Comp settings DehumidificationDehumidification Low Limit Dehumidification Compressor QuantityControl Types Temperature and Humidity Control TypesReheat During Dehumidification Humidity Sensor Reading Control Types High and Low, Temperature and Humidity Events Supply Limit-OptionalUser Inputs / Customer Inputs Customer inputsTime Delay Enable or DisableEvent Types and Properties Event TypesMain FAN Overload Possible Event Notifications Event notifications-large or small displayCalculation of Next Maintenance and Diagnostics Next Maintenance CalculationCalculating Unit Wellness Parameters for Next Maintenance Calculation General Maintenance SettingsFans / Heaters / Humidifier Settings and Diagnostics Compressor 1 / 2 Settings and DiagnosticsTeamwork Mode Teamwork ModesApplication of Teamwork Modes No TeamworkTeamwork Mode 1 with two cooling units Standby Rotation Typical Standby Lead/Lag Function Standby and CascadeU2U Hardware Cables and Network Switch Placement of Cooling UnitsMinimum Network Switch Requirements Sample Liebert iCOM network configurations Wiring for Unit-to-Unit Communications-U2ULiebert iCOM U2U Ethernet Network Wiring a Liebert iCOM U2U Network Small Displays Large DisplaysWall-Mount Large Display Combining Large and Small Displays on a U2U NetworkWiring a small display for stand-alone operation Wiring a large display for stand-alone operation Ports available for connecting Liebert iCOM control devices Liebert vNSA298 84mm 305mm 14.25 362mm DPN001136 Rev Necessary Mounting Items Location ConsiderationsMounting Instructions Liebert iCOM display dimensions Spare Part List-Large Display Only Setpoints parametersSpare part list parameters-large display only Event log parametersSet alarms parameters Sensor dataActive alarms parameters Active AlarmsDisplay setup parameters Timer parameters-Sleep Mode Total run hours parametersService contacts parameters Service Menu Parameters Unit Diary-Large Display Only Unit diary parametersStandby settings / lead-lag parameters Maintenance / wellness settings parametersWellness COMP2 Wellness HEAT2 Diagnostics / service mode parameters ALM REL 7of Delay Enable Disab Enable Disab Comp 1 Overload Unit X Disconnected WRN Loss of Power LOP MSG, WRN, ALM Call Service MSG, WRN, ALM High Temperature Sensor calibration / setup parameters System / network setup parameters-large display only Network setup parameters GBPStatic RAM Not Available, Invalid, OK Options setup parameters HUM SteamService contact info parameters Service Menu Parameters Service Menu Parameters Page Ne t ItiTi n That