Precision Cooling For Business-Critical Continuity Liebert Challenger™ 3000 Operation & Maintenance Manual - 3 & 5 Ton, 50 & 60Hz
TABLE OF CONTENTS 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 1.1 System Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1.1 1.1.2 1.1.3 Compressorized Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 GLYCOOL™ (Chilled Glycol Cooling) Systems . . . . . . . . . .
3.7.1 3.7.2 3.7.3 3.7.4 3.7.5 3.7.6 3.7.7 3.7.8 3.8 Setup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Select Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calibrate Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calibrate Valve Actuator . . . . . . . .
4.4.2 4.5 Sequential Load Activation Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Additional Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.5.1 4.5.2 Connecting the Analog Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Water Detection Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.5 Humidifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 6.5.1 6.5.2 Infrared Humidifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Steam Generating Humidifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 7.0 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FIGURES Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Advanced microprocessor control panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Advanced microprocessor (A) control for Challenger 3000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Advanced microprocessor with graphics (G) control panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Introduction 1.0 INTRODUCTION 1.1 System Descriptions Challenger 3000™ Liebert environmental control systems are available in several configurations. Each configuration can operate with either Advanced Microprocessor Controls (A), or Advanced Microprocessor Controls with Graphics (G). A brief description of each, including operational differences, are listed below. Check model numbers to see what is supplied with your unit. 1.1.
Introduction 1.2 Start-Up Procedure Before beginning start-up, make certain that unit was installed according to the instructions in the Installation Manual. Verify that the fan shipping bolt has been removed, the check valve has been installed (on air cooled units), and that the scroll compressor is rotating in the proper direction. All exterior panels must be in place with the front panel open. Locate the start-up form supplied with your unit documents.
Operation with Advanced Microprocessor Controls 2.0 OPERATION WITH ADVANCED MICROPROCESSOR CONTROLS The advanced microprocessor (A) control for your Liebert Challenger 3000 unit features an easy-touse menu driven LCD display. The menus, control features, and circuit board details are described in this section. For more control details, refer to 4.0 - System Performance with Advanced Microprocessor Controls, and for more alarm information, refer to 5.0 - Alarm Descriptions. 2.
Operation with Advanced Microprocessor Controls Figure 2 Advanced microprocessor (A) control for Challenger 3000 Normal Display Main Menu 72°F 50%RH Cooling Dehumidifying No Alarms Present Status/Alarm Data Setpoints/Setup Date and Time Status Display Status Alarm Data Setpoints/Setup View Setpoints Setup System Run Diagnostics Change Passwords Active Alarms Operating Status Alarm History Log Run Hours Log Active Alarms Alarm History Log Operating Status Run Hours Log No Alarms Present Alarm H
Operation with Advanced Microprocessor Controls 2.2 Status Display The display normally shown includes the present room temperature, humidity, active status functions (cooling, heating, dehumidifying, humidifying), and active alarms. If no keys are pressed within 5 minutes, the system automatically returns to the Status Display. The Status Display may also be selected from the Main Menu. 2.3 Main Menu
Operation with Advanced Microprocessor Controls 2.4.4 Run Hours Log The total operating hours of all major components in the unit can be monitored from the display and are retained in nonvolatile memory.
Operation with Advanced Microprocessor Controls 2.5.2 Setup System The Setup System menu includes the following selections: • • • • • • • • • • SETUP OPERATION SELECT OPTIONS CALIBRATE SENSORS SHOW DIP SWITCHES SELECT CONTROL TYPE (Chilled Water or SCR Reheats only) SETUP ALARMS HUM CONTROL METHOD ANALOG SETUP SET STATUS DISPLAY CALIBRATE ACTUATOR Setup Operation The Setup Operation menu permits the review and/or adjustment of the unit configuration.
Operation with Advanced Microprocessor Controls Table 2 lists the setup functions, their factory default values and the allowable programming ranges. Table 2 Setup functions, default values and ranges Function Default Range Cold Start Time Delay* Restart Time Delay 3 0.1 0 to 3 min (0 = no delay) 0 to 9.
Operation with Advanced Microprocessor Controls Select Control Type • Intelligent (Chilled Water only) • Proportional (all unit types) • Tunable PID (Chilled Water or SCR Reheats only) The type of system control method used by the microprocessor can be selected from the front panel. The default setting is Intelligent, which approximates the actions that a human operator would take to maintain precise, stable control.
Operation with Advanced Microprocessor Controls Enable Alarms—Each individual alarm can be selected to be ENABLED (annunciated audibly, visually, and communicated to a Site Products System) or DISABLED (ignored). Enable Common Alarm—Each individual alarm can be selected to energize or to not energize the common alarm relay.
Operation with Advanced Microprocessor Controls Analog Setup For installation of analog sensors, see 4.5.1 - Connecting the Analog Sensors. After selecting a compatible sensor and properly wiring it to the terminals, set up the control to monitor the sensor as follows: Slope—The slope is a multiplier used to scale the input signal. The slope can be positive (rising) or negative (falling) and can range from 0 (resulting in a horizontal line) to ±999.
Operation with Advanced Microprocessor Controls 2.5.3 Run Diagnostics By selecting Run Diagnostics, maintenance personnel can check system inputs, outputs, and complete a test of the microcontroller circuit board, all from the front panel. Review of the system inputs and the microcontroller test can be done without interrupting normal operation. To test the system outputs, the normal system control is temporarily suspended.
Operation with Advanced Microprocessor Controls 2.5.4 Change Passwords The display prompts you to enter a three digit password when making changes. The system includes two (2) passwords, one for setpoints and one for setup. The system allows the passwords to be changed by first entering the present password, factory set as “123” for setpoints and “321” for setup. The password function provides system security, so only personnel authorized to make changes should know the passwords.
Operation with Advanced Microprocessor Controls 2.8.2 Non-Volatile Memory All critical information is stored in nonvolatile memory. Setpoints, setup parameters, and component run hours are kept inside the microcontroller in EEPROM. Information retained for the alarm history is kept in non-volatile RAM. 2.8.3 DIP Switches Equipment options are selected and enabled using DIP switches 1 through 7. These are located at the upper left of the control board and are labeled SW1. Switch 1 is at the top.
Operation with Advanced Microprocessor with Graphics Control 3.0 OPERATION WITH ADVANCED MICROPROCESSOR WITH GRAPHICS CONTROL The advanced microprocessor with graphics (G) control for your Liebert Challenger 3000 unit features an easy to use, menu driven LCD Graphics Display. The menus, control features, and circuit board details are described in this section. For more details on the control refer to 4.0 - System Performance with Advanced Microprocessor Controls; for details on the alarms refer to 5.
Operation with Advanced Microprocessor with Graphics Control Figure 4 Advanced microprocessor with graphics control menu Use UP/DOWN to move the cursor. Hit ENTER to select the menu item.
Operation with Advanced Microprocessor with Graphics Control 3.2 Status Display The normal status screen is divided into two sections, a right half and a left half. The left half displays the return air temperature and humidity readings in large characters. NOTE The display can also be set to display the temperature and humidity setpoints. See 3.7.7 - Set Status Display. The right half of the screen is divided into four quadrants (top to bottom).
Operation with Advanced Microprocessor with Graphics Control 3.4.3 Setup Alarms The list of alarms may be reviewed using the UP/DOWN keys. Any alarm may be selected to have it's parameters modified by pressing the ENTER key. All alarms have a time delay and alarm type parameter. The high/low temperature and humidity alarms also have a programmable Trip Point. The Trip Point is the point at which the alarm is activated.
Operation with Advanced Microprocessor with Graphics Control 3.4.4 Setup Custom Alarms Selecting SETUP CUSTOM ALARMS will step to the following menu: • • • • • SETUP CUSTOM ALARM TEXT CHANGE CUSTOM TEXT 1 CHANGE CUSTOM TEXT 2 CHANGE CUSTOM TEXT 3 CHANGE CUSTOM TEXT 4 The custom alarm messages can be selected from a list of standard messages or you can write your own messages. The message selected for any custom alarm can be changed at any time by selecting SETUP CUSTOM ALARM TEXT.
Operation with Advanced Microprocessor with Graphics Control 3.5 Operating Status The Operating Status is intended to provide the user with displayed information about what the control is calling for the system to do. NOTE There may be some time lapse before a specific component matches the displayed number. For example: The display indicates the chilled water valve is 68% open. On a new call for cooling, it takes several seconds for the valve to travel from full closed to 68% open.
Operation with Advanced Microprocessor with Graphics Control Auto Restart Delay This feature allows for the unit to restart automatically after a loss of power. The programmed value is .1 minute (6 seconds) intervals. A programmed value of zero (0) would require the user to manually press the ON/OFF switch to start the unit, i.e. no auto restart. The purpose of this feature is to prevent several units from starting at the same time after a loss of power.
Operation with Advanced Microprocessor with Graphics Control 3.7.2 Select Options The following table is a list of options which should match the options installed with your unit and should not need to change during normal operation. Table 10 Unit options Option Selection 1 YES or NO Humidity YES or NO Reheat Dehumidify YES or NO Hot Gas Reheat2 YES or NO Stages of Reheat3 2 1 Heating cannot be disabled on units with SCR reheats. gas reheat not available on units with SCR reheats.
Operation with Advanced Microprocessor with Graphics Control 3.7.6 Select Humidity Sensing Mode The user may select between RELATIVE (direct) and ABSOLUTE (predictive) humidity control. If relative is selected, the RH control is taken directly from the RH sensor. If absolute is selected, the RH control is automatically adjusted as the return air temperature deviates from the desired temperature setpoint. This results in a predictive humidity control.
Operation with Advanced Microprocessor with Graphics Control 3.8.
Operation with Advanced Microprocessor with Graphics Control 3.8.4 DIP Switches The DIP switch settings can be reviewed from the display panel. Changing the DIP switches requires opening the front panel for access to the DIP switches on the microprocessor control board. NOTE Power MUST be cycled off, then on, from the unit disconnect switch for the control system to update the DIP switch settings (except for switch 8).
Operation with Advanced Microprocessor with Graphics Control 3.11 Analog/Digital Inputs Selecting ANALOG/DIGITAL INPUTS steps to the following menu: • • • • READ ANALOG INPUTS SETUP ANALOG INPUTS READ DIGITAL INPUTS SETUP DIGITAL INPUTS 3.11.1 Read Analog Inputs The four (4) analog sensor inputs can be monitored from the display. The inputs are filtered, then displayed along with the text label assigned during setup. 3.11.
Operation with Advanced Microprocessor with Graphics Control 3.12.1 View 24 Hour Run Time History The history of each load for every hour during the past 24 hours is displayed in the run hour history. The percentage of each hour that the load was on is displayed from 0 to 100% in increments of 5% or 3 minutes. Loads with a variable output are displayed as a percentage of their capacity for an hour. For example, a variable load that is 50% on for 1/2 of the hour will be displayed as 25% on for that hour.
Operation with Advanced Microprocessor with Graphics Control 3.13.2 Nonvolatile Memory All critical information is stored in nonvolatile memory. Setpoints, setup parameters, and component run hours are kept inside the microcontroller in EEPROM. Information retained for data logging, 24 hour component run hour graphs, alarm history, and the water detection floor plan is kept in nonvolatile RAM. 3.13.3 DIP Switches Equipment options are selected and enabled using DIP switches 1 to 7.
System Performance with Advanced Microprocessor Controls 4.0 SYSTEM PERFORMANCE WITH ADVANCED MICROPROCESSOR CONTROLS This section provides details on how your Challenger 3000 unit responds to user inputs and room conditions. Refer to this section when you need specific information. This section includes details on control. 4.1 Temperature Control 4.1.
System Performance with Advanced Microprocessor Controls 4.1.3 Cooling Operation 1-Step Cooling, Compressorized Direct Expansion (DX) Systems Cooling activates when the temperature control calculates a requirement for cooling of 100%. It is deactivated when the cooling requirement drops below 50%. The hot gas bypass is energized on a call for cooling unless there is also a call for dehumidification.
System Performance with Advanced Microprocessor Controls 4.1.4 Heating Operation Electric Reheat The two heat stages are activated when the temperature control calculates a requirement of 50% and 100%, respectively. Each stage is deactivated when the heat requirement is 25% less than the activation point. Hot Water Reheat The solenoid valve opens when the requirement for heating is 100% and closes when the requirement drops below 50%.
System Performance with Advanced Microprocessor Controls 4.2.4 Humidification Operation System Activation The humidifier (infrared or steam) is activated when the humidity control calculates a requirement of 100% humidification, and deactivated when the requirement falls below 50%. 4.3 Control Types 4.3.1 Proportional Control This is a standard control method that maintains the room at a temperature proportional to the load. The temperature maintained increases as the room load increases.
System Performance with Advanced Microprocessor Controls A suggested tuning procedure is as follows: 1. Initially adjust the integral and derivative settings to 0%/ degree-min and 0% /degree/min. 2. Starting with 20% /degree, adjust the proportional setting in small increments (10% steps) until the control sustains a constant hunting action (the temperature swings are approximately the same amplitude from one peak to the next). 3.
System Performance with Advanced Microprocessor Controls 4.4 Load Control Features 4.4.1 Short Cycle Control The control system monitors the compressor and prevents it from turning on within 3 minutes of being turned off. If this (on, off, on) occurs too often, 10 times in one hour, a Short Cycle alarm could occur. 4.4.2 Sequential Load Activation Control The control allows only one load output to be energized at a time on a restoration of power or microcontroller reset.
System Performance with Advanced Microprocessor Controls Figure 5 Analog input jumpers Analog input jumper location ENLARGED AREA 4.5.2 Water Detection Display The water detection display is designed to graphically display the location of water under a raised floor when connected to an LT750 water detection system. The graphical floor plan screen shows a 30 x 16 grid. Each square represents one standard floor tile (approximately 2 ft. x 2 ft.).
System Performance with Advanced Microprocessor Controls Physical Connections Figure 6 shows the 4-20 mA output of LT750 connected to Analog Input #1 (41 and 42) on the external inputs terminal strip. This strip is provided on units ordered with analog inputs. (If this strip is not installed, there is a field installation kit available from your Liebert representative.) The 4-20 mA output of the LT750 must be connected to the first analog input, as shown. TB4 is the water detected relay output.
System Performance with Advanced Microprocessor Controls 4.6 Communications The control system uses a two-wire, RS-422 channel to communicate with remote monitoring systems via Liebert Site Products. This communication, directly out of the control, uses a proprietary protocol. Your unit can have a variety of different Site Product devices wired to this port depending on the monitoring system you are using.
Alarm Descriptions 5.0 ALARM DESCRIPTIONS The Advanced Microprocessor (A) and the Advanced Microprocessor with Graphics (G) Control systems will audibly and visually annunciate all ENABLED alarms, including the four custom alarms. With the Advanced & Advanced with Graphics Controls, the customer alarms can be from the optional alarm list and/or can have their own fully custom text.
Alarm Descriptions 5.1.2 Compressor Overload An optional tri-block overload device can be used for the compressor. Compressor overload may be manual or automatic reset, depending on your model. Overload is located at the electric connection box on the compressor. 5.1.3 Custom Alarms Custom alarm messages are programmed at the LCD display. The alarms may be specified by the customer at the time of order. Additional devices and wiring may be required at the factory or by others.
Alarm Descriptions 5.1.8 High Temperature and Low Temperature (Simultaneously) If these two alarms are displayed at the same time, the temperature input signal is lost (or the humidity is out of sensor range: 15 to 85% RH). Dashes will be displayed for the temperature reading. The control system will initiate 100% cooling. Check for a disconnected cable or a failed sensor. 5.1.9 Humidifier Problem Infrared Humidifiers This alarm is activated by the high water float switch in the humidifier pan assembly.
Alarm Descriptions 5.1.16 Short Cycle On compressorized systems, if the compressor has exceeded 10 cooling starts in one hour or if the compressor has cycled five times in 10 minutes on the low pressure switch during non-cooling, the Short Cycle alarm will occur. This can be caused by low refrigerant level (but not low enough to activate Low Suction Pressure alarm) or room cooling load is small compared to capacity of the unit. Check for leaks, crimped lines, and defective components.
Component Operation and Maintenance 6.0 COMPONENT OPERATION AND MAINTENANCE 6.1 System Testing 6.1.1 Environmental Control Functions The performance of all control circuits can be tested by actuating each of the main functions. This is done by temporarily changing the setpoints. Cooling To test the cooling function, set the setpoint for a temperature of 10°F (5°C) below room temperature. A call for cooling should be seen and the equipment should begin to cool. A high temperature alarm may come on.
Component Operation and Maintenance Firestat The optional firestat is a bimetal operated sensing device with a normally closed switch. This device will shut down the entire unit when the inlet air temperature exceeds a preset point. It is connected between terminals 1 and 2 at plug P39. Smoke Detector The optional smoke detector power supply is located on the base of the upflow units, and at the top of downflow units. It is constantly sampling return air through a tube. No adjustments are required.
Component Operation and Maintenance The zone leak detection kit provides leak detection for a defined zone. This kit is ideal for perimeter sensing or serpentine coverage of small areas. A simple, two-wire connection signals the alarms at a Liebert environmental unit or at a monitoring panel. Run wires to the Liebert unit and connect them to terminals 24 and 51, 55 or 56. The sensor utilizes Liebert's LT500Y leak detection cable.
Component Operation and Maintenance 6.3 Blower Package Periodic checks of the blower package include: belt, motor mounts, fan bearings, and impellers. 6.3.1 Fan Impellers and Bearings Fan impellers should be periodically inspected and any debris removed. Check to see if they are tightly mounted on the fan shaft. Rotate the impellers and make sure they do not rub against the fan housing. Bearings used on the units are permanently sealed and self-lubricating.
Component Operation and Maintenance 6.4 Refrigeration System Each month, the components of the refrigeration system should be inspected for proper function and signs of wear. Since, in most cases, evidence of malfunction is present prior to component failure, periodic inspections can be a major factor in the prevention of most system failures. Refrigerant lines must be properly supported and not allowed to vibrate against ceilings, floors or the unit frame.
Component Operation and Maintenance 6.4.4 Thermostatic Expansion Valve Operation The thermostatic expansion valve performs one function. It keeps the evaporator supplied with enough refrigerant to satisfy load conditions. It does not effect compressor operation. Proper valve operation can be determined by measuring superheat. If too little refrigerant is being fed to the evaporator, the superheat will be high; if too much refrigerant is being supplied, the superheat will be low.
Component Operation and Maintenance 6.4.6 Air Cooled Condenser Restricted airflow through the condenser coil will reduce the operating efficiency of the unit and can result in high compressor head pressure and loss of cooling. Clean the condenser coil of all debris that will inhibit air flow. This can be done with compressed air or commercial coil cleaner. Check for bent or damaged coil fins and repair as necessary. In winter, do not permit snow to accumulate around the sides or underneath the condenser.
Component Operation and Maintenance 6.4.7 Water/Glycol Cooled Condensers Coaxial Condenser Each water or glycol cooled module has a coaxial condenser which consists of a steel outside tube and a copper inside tube. Coaxial condensers do not normally require maintenance or replacement if the water supply is clean. If your system operates at high head pressure with reduced capacity, and all other causes have been eliminated, the coaxial condenser may be obstructed and needs to be replaced.
Component Operation and Maintenance High Pressure Valve - 350 PSIG System (2413 kPa) for 3 Ton Units (Metrex Valve) Adjustment—The valve may be adjusted using a 1/8" diameter rod. Turn adjusting collar nut counterclockwise to raise head pressure. Turn it clockwise to lower head pressure. Rotation directions are as viewed from top of valve spring housing. Figure 11 Metrex valve adjustment Adjusting Collar Nut Manual Flushing—The valve may be flushed by rotating the socket head screw clockwise.
Component Operation and Maintenance 6.4.8 Compressor Functional Check The following diagnostic procedure should be used to evaluate whether the compressor is working properly. 1. Proper voltage to the unit should be verified. 2. The normal checks of motor winding continuity and short to ground should be made to determine if the inherent overload motor protector has opened or if an internal motor short or ground fault has developed.
Component Operation and Maintenance Electrical Failure An electrical failure will be indicated by a distinct pungent odor. If a severe burnout has occurred, the oil will be black and acidic. In the event that there is an electrical failure and a complete burnout of the refrigeration compressor motor, the proper procedures must be performed in order to clean the system to remove any acids that would cause a future failure.
Component Operation and Maintenance 6.5 Humidifier 6.5.1 Infrared Humidifier During normal humidifier operation, deposits of mineral solids will collect in the humidifier pan. This should be cleaned out periodically to ensure efficient operation. Each water supply has different characteristics, so the time interval between cleanings must be determined locally. A monthly check (and cleaning if necessary) is recommended.
Component Operation and Maintenance Autoflush Infrared Humidifier Cleaning System NOTE To operate properly, the Autoflush Humidifier requires a water source that can deliver at least 1 gpm (0.063 l/s) with a minimum pressure of 20 psig (138 kPa). The autoflush system will periodically flush the humidifier pan with water to prevent the buildup of water minerals due to saturation. Because water conditions vary, the amount of water flushing through the system may be programmed to match local needs.
Component Operation and Maintenance Operation 1. During start-up, when the humidity control calls for humidification, the fill valve opens and allows water to enter the canister. When the water level reaches the electrodes, current flows and the water begins to warm. The canister fills until the amperage reaches the setpoint and the fill valve closes. As the water warms, its conductivity increases and the current flow, in turn, rises.
Component Operation and Maintenance Replacing the Canister Over a period of operation, the humidifier electrodes become coated with mineral solids. This coating insulates the electrodes and decreases the current flow. To maintain humidifier capacity, the water level slowly rises to expose fresh electrode. Eventually, the entire electrode becomes coated and the water level reaches the top. At this point, the canister full alarm is activated and the output begins to fall.
Component Operation and Maintenance Figure 14 Canister replacement Circuit Board Adjustments ! WARNING Circuit board adjustment should be performed by qualified personnel only. Hazardous voltages are present in the equipment throughout the procedure. Use extreme caution. If desired, power may be disconnected prior to the procedure. Humidifier operation is governed by the humidifier control board. This board is located on the right side of the humidifier compartment.
Troubleshooting 7.0 TROUBLESHOOTING Use this section to assist in troubleshooting your unit. Also refer to 5.0 - Alarm Descriptions. Suggestions are grouped by product function for convenience. Table 21 ! WARNING ! CAUTION Only qualified personnel should perform service on these units. Lethal voltage is present in some circuits. Use caution when troubleshooting with power on. Disconnect and lock out power before replacing components.
Troubleshooting Table 23 Compressor and refrigeration system troubleshooting Symptom Possible Cause Check or Remedy Power off Check main switch, fuses or CBs and wiring Current overload open Re-set units with overload option manually. Allow compressor to cool for internal overloads to reset. Loose electrical connections Tighten connections Compressor motor burned out Check and replace compressor if defective. No call for cooling Check monitor status.
Troubleshooting Table 23 Compressor and refrigeration system troubleshooting (continued) Symptom Possible Cause Check or Remedy Defective or improperly set expansion valve Increase superheat or replace valve Evaporator fan motor or belt Correct problem or replace fan motor and/ or belts. Low condensing pressure Check head pressure control device Slipping belts Inspect and adjust Compressor rotation in reverse direction. Check for proper power phase wiring to unit and to compressor motor.
Troubleshooting Table 24 Dehumidification troubleshooting Symptom No dehumidification Table 25 Possible Cause Check or Remedy Control not calling for dehumidification Check monitor status. Compressor contactor not pulling in See 6.4.8 - Compressor Functional Check and Table 23. Compressor won't run; fuse blown or CB tripped See 6.4.8 - Compressor Functional Check and Table 23. Check fuses or CBs and contacts.
Troubleshooting Table 27 Steam generating humidifier troubleshooting Symptom Possible Cause Check or Remedy Check drain valve to ensure that it drains freely. Check and replace if defective. Foaming Check water supply. If commercially softened, reconnect to raw water supply. If connected to hot water reconnect to cold water. Main 24 VAC fuse or circuit breaker trips Shorts or loose connections Check the wiring connections of the 24 VAC circuit. Faulty circuit board Replace the circuit board.
Troubleshooting Table 27 Steam generating humidifier troubleshooting (continued) Symptom Possible Cause Check or Remedy Drain valve clogged or defective Verify that drain valve operates freely when activated. Clean valve and replace coil or valve if defective. Flush canister several times and replace if arcing persists. Improper water supply If water is commercially softened, reconnect humidifier to raw water supply, drain canister, and restart If connected to hot supply, reconnect to cold water.
Monthly Maintenance Inspection Checklist 8.0 MONTHLY MAINTENANCE INSPECTION CHECKLIST Date:_______________________________________ Prepared by:_________________________________ Model #:_____________________________________ Serial #:____________________________________ Filters ___ 1. Restricted air flow Steam Generating Humidifier ___ 1. Check canister for deposits ___ 2. Check filter switch ___ 2. Check condition of steam hoses ___ 3. Wipe section clean ___ 3.
Semiannual Maintenance Inspection Checklist 9.0 SEMIANNUAL MAINTENANCE INSPECTION CHECKLIST Date:________________________________________ Prepared by:_________________________________ Model #:_____________________________________ Serial #:_____________________________________ Filters Steam Generating Humidifier ___ 1. Restricted air flow ___ 2. Check filter switch ___ 3. Wipe section clean ___ 1. ___ 2. ___ 3. ___ 4. Blower Section ___ 1. ___ 2. ___ 3. ___ 4.
Semiannual Maintenance Inspection Checklist 66
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