AFX Series Precision Air Conditioning OPERATION AND MAINTENANCE MANUAL February 10, 2003 This manual provides information for installation, operation and preventive maintenance. The user should observe the guidelines and procedures presented herein to promote satisfactory performance. Due to an ongoing program dedicated to product improvement, specifications are subject to revision without notice.
Introduction Congratulations on the selection of an APC environmental control system. The unit incorporates the latest system design innovations to provide you with optimum efficiency, reliability and control accuracy. The AFX Series System will provide years of trouble free service, provided it is installed and maintained by technically qualified personnel in accordance with the guidelines set forth in this manual. Table of Contents Introduction ............................................................
The AFX Series The APC AFX series precision air-conditioning system provides compact, quiet, efficient, and reliable system solutions in the expanding precision air-conditioning market. The AFX series is offered in a wide variety of capacities, configurations, and air patterns within an extremely compact cabinet size.
Standard Features Overall cabinet The frame is constructed of heavy gauge steel for maximum strength. The unit has been designed for full service access from the front. The flush mounted panels are removable using quarter-turn fasteners. Blower Assembly The AFX series includes multiple, centrifugal blower assemblies that have been engineered for quite, reliable operation. Lower blower speeds reduce noise and extend belt and bearing life to 200,000L10.
Optional Equipment Smoke detector(s) A factory installed smoke detector is designed to sense smoke concentration in the return air stream. Upon detecting smoke concentration an audible and visual alarm will be activated and the unit will immediately shut down. Firestat A Firestat is available for installation in the air stream. If the return air temperature reaches 125° F (52° C), the air conditioner will be turned off and both an audible and visual alarm will be activated.
Optional Equipment (continued) Environmental monitoring unit A stand-alone unit performs continuous temperature and humidity sensing through two available probes (one included) and contact monitoring. The unit is controlled by available web, control console, or SNMP interface with network connection. In the event of an environmental anomaly, notification is sent to the customer via e-mail or SNMP. The unit is 18.25" × 9" × 2.75" (464 mm × 229 mm × 70 mm) and sits in or on top of a rack.
Installation Computer Room Preparation During the design of the computer room, consideration should be given to the following factors: ease of entry, floor loading factors and accessibility of piping and wiring. The room must be sealed with a vapor barrier to minimize moisture infiltration. Polyethylene film (plastic sheeting) is a good vapor barrier for ceiling and wall applications. Rubber or plasticbased paints should be applied to concrete floors and walls.
Installation (continued) UPFLOW DISCHARGE In data processing facilities designed for upflow discharge systems, air distribution is either through a supply duct or through a discharge plenum into the conditioned space. The same unit location considerations for a downflow discharge system also apply to upflow discharge systems. FLOORSTAND When using a stand on raised floors, remove or cut the flooring to fit the floor stand dimensions.
Installation (continued) Power Connection The AFX unit uses three phase power for operation. Bring the service cable through the 3/4" bulk head hole near the electric box and connect it to the power distribution block provided on the left side of the electric box. All wiring must be done in accordance with local and national electric codes. Utility Connections All connections are made through the side of the mechanical section of the air conditioner for ease of service connection.
Installation (continued) Drycooler and Pump Package Connection Provide sufficient valves and unions to isolate the dry cooler and pump package during routine service or in the event of an emergency. Pipe should be welded wherever possible to minimize leak possibility. Pipe and wire the dry cooler/precool system in accordance with local and national codes. A wiring diagram is attached to the inside of each control panel cover.
Piping Connections Refrigerant Pipe Connections; AIR-COOLED When piping air-cooled systems, care must be taken to use only clean refrigerant grade (Type L) pipe and follow standard procedures for pipe size selection. Maximum recommended distance between the evaporator and condenser is 200 equivalent feet. For any run beyond this distance contact the factory for assistance. Vertical runs (hot gas) require a trap every 20 feet of rise.
Pre Start-Up Prior to initial start-up, perform the following checks to ensure proper unit operation: ELECTRICAL CHECKS 1. Check to make sure that incoming voltages match the nameplate's phase and voltage listings. 2. Make sure that the unit is properly grounded to an earth ground. 3. Check all internal electrical components and terminal blocks for loose connections, which may have been caused by shipping vibrations. 4. Check that all fuses are correct and securely in the fuse blocks. 5.
Charging the System The AFX Series Water/Glycol and the integral mounted Air-cooled systems are factory charged with refrigerant. All other direct expansion systems must have the piping evacuated and the system charged. All refrigerant connections should be leak tested before the system is charged with refrigerant. The complete system should be pressured to 400 psig with refrigerant and dry nitrogen. Use an electronic leak detector to carefully check each joint.
Control/Safety Adjustments After the installation and start-up of the AFX Series unit has been completed, "fine tuning" of the system's controls and safety systems is necessary, as described below. Belt Tension The blower motor is mounted on an adjustable base. Belt tension can be increased or decreased by raising or lowering the base. A deflection of about 3/4 - 1" per foot of span between the blower and motor pulleys should be obtained by pressing the belt firmly.
Control/Safety Adjustments OVERLOAD RELAY The blower motor starter has an adjustable overload relay. The adjustment dial should be set to correspond to the full load amperes (FLA) on the blower motor. The overload has a manual reset button to prevent the motor from cycling on the overload switch. FIRESTAT The firestat used in this unit has a manual reset and an adjustable temperature setting. The firestat is factory set prior to shipment to trip when temperatures above 125?F are detected.
Humidifier Operation Your AFX Series unit may be equipped with a pure steam generator type humidifier as an option. Check all electrical connections for wires, which may have become loose in shipping. Components burnt due to loose connections are NOT covered under warranty. Check electrode plugs to ensure they are pressed firmly onto the electrode pins. Important: Loose connections will cause overheating of the cylinder plugs and probable melting of the plugs and/or cylinder.
Troubleshooting PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION Controls erratic or inoperative Wiring improperly connected or broken. Check wiring connections at schematic. Evaporator coil ices Usually caused by lack of proper quantity of airflow across coil. Check filters; clean if necessary. Check for obstruction of airflow in duct system. Unit is designed for ½” s.p. (ext.) W.P. approximate. Low return air temperature. Ensure correct rotation of evaporator blowers.
Troubleshooting PROBLEM Compressor short cycles. Noisy compressor. System short of capacity. 17 POSSIBLE CAUSE CORRECTIVE ACTION Low line voltage causing compressor electric motor to overheat. Check power source for cause of variation of line voltage. Dirty or icy evaporator (reduce air flow). Defrost and/or clean. Lack of refrigerant (bubbly sight glass). Repair leak and recharge system. Light load. Configure controller for light load. Defective LP switch Check and/or replace.
Troubleshooting PROBLEM Head pressure too high. POSSIBLE CAUSE CORRECTIVE ACTION Condenser clogged or dirty. Clean condenser. Air or other non-condensable gas in system Evacuate system and recharge. Install new drier strainer. O.H.E. air intake blocked. Clean away debris. Overcharge of refrigerant. Purge or remove excess from high pressure side of system Pump overloads tripped (glycol system). Reset and check cause. O.H.E. fans not operating. Check fuses and motor. Replace as needed.
Troubleshooting PROBLEM Humidifier inoperative. Reheat elements inoperative. Water carryover. POSSIBLE CAUSE CORRECTIVE ACTION Water not hooked up. Turn on water. Electrical connections loose. Tighten electrical connections Humidifier fuse open. Check for short circuit. Replace if necessary. Relative humidity is above the setpoint. No corrective action needed. Overheat switch actuated. Reset and check. Fuse open. Check for short circuit. Replace if necessary. Thermostat set too low.
Preventive Maintenance The operating life of the AFX Series system can be extended by following a simple preventive maintenance schedule. The schedule will reduce the possibility of failure of components and unnecessary malfunction of the system. The service technicians must be thoroughly familiar with the special design features of this equipment before attempting any service or repair. MONTHLY 1. Check that filters are clean and in place. 2. Check that condensate drain is open. 3.
Warranty The limited warranty provided by American Power Conversion Corporation ("APC") in this Statement of Limited Factory Warranty applies only to Products you purchase for your commercial or industrial use in the ordinary course of your business.
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