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Scope of Services DX & Glycol HVAC

DX AND GLYCOL COMPUTER ROOM AC (CRAC) SYSTEM PREVENTIVE MAINTENANCE - SCOPE OF WORK 

  Minor PM  

SYSTEM CONTROLS & MICROPROCESSOR OPERATION
Visual inspection and check:

  • Ensure microprocessor and or solid state control system is functioning properly  
  • Verify the parameters, and adjust to verify the operation of the reheats and mechanical cooling and ECONO-COOL operation  If applicable record the components run hours  
  • Operation of the relays, contactors, and check contacts for pitting and burning
  • All electric connections and terminals for tightness with power off (using a voltmeter), and check voltage all units should be +10% of nameplate

EVAPORATOR
Visual inspection and check:

  • Evaporator condition
  • For refrigerant leaks
  • The drain lines for obstructions and corrosion

HEAT REJECTION DEVICE: DX CONDENSER / DRY COOLER / INTERNAL GLYCOL CONDENSER
Visual inspection and check:

  • For refrigerant leaks / glycol leaks  
  • Overall condition of the coil, system refrigerant or glycol piping, electrical components, and wiring
  • Verify low ambient control being utilized, and verify the operation maintains proper head pressure during low ambient operation

HUMIDIFIER SYSTEM INFRARED AND STEAM
Visual inspection and check:

  • Steam / Infrared humidifier operation; clean either as required
  • If automatic water flush system is used to prevent mineral deposits, check timer operation
  • Condensate pump operation, clean and flush as required

REHEAT AND DEHUMIDIFICATION
Visual inspection and check:

  • General condition of heaters, relays, and contactors.

REFRIGERANT – CIRCUIT / COMPRESSOR SECTION
Visual inspection and check:

  • System compressors oil level and  refrigerant leaks
  • Refrigerant sight glass moisture indicator  

FAN AND FAN DRIVES
Visual inspection and check:

  • Check bearings for noise and excessive wear  Blower Motor & Belt condition for tightness, and adjust or replace as needed
  • Drives and pulleys for tightness and excessive wear 

FILTERS

  • Check filters

  

  Major PM  
  – Includes all tasks done during Minor PM visit plus the following:  

HEAT REJECTION DEVICE: DX CONDENSER / DRY COOLER / INTERNAL GLYCOL CONDENSER

Power wash coils: if possible remove any paper, leaves, and debris within four feet of the condensers

  • Tighten electrical connections and record currents of the condenser fan motors and glycol pump
  • If the associated units have the ECONO-COOL option the recommend out door fan settings is 50 degrees for a single fan system, 50 and 54 degrees for systems with multiple fans and verify glycol freeze point

REFRIGERANT – CIRCUIT / COMPRESSOR SECTION

  • Use Mego-Meter to determine the condition of the compressor windings 
  • Tighten Electrical connections and Record currents of the compressors 
  • Use refrigeration gauges to monitor suction and discharge pressure, verify superheat and record 
  • Check super heat and record 

HUMIDIFIER SYSTEM INFRARED AND STEAM

  • Tighten electrical connections and record currents

REHEAT AND DEHUMIDIFICATION

  • Tighten electrical connections and record currents

FAN AND FAN DRIVES

  • Lubricate fan and motor bearings, install grease fittings if not supplied with unit (if applicable) 
  • Tighten electrical connections and record currents of the motor 
  • Alignment of sheave or pulleys as required

FILTERS

  • Replace air filters as required


Documentation of inspection with recommendations for any corrective action deemed necessary will be provided on both Minor and Major PMs .