Chilled Water, DX & Glycol HVAC 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, chilled water 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
• Chilled water control actuator valve

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/chilled water piping, electrical components, and wiring. Verify chilled water temperature
• 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 all 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 recommended outdoor fan settings is 50 degrees for a single fan system, 50 and 54 degrees for systems with multiple fans and the glycol freeze point needs to be verified.

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

CHILLED WATER SYSTEMS

• Check chilled water supply temperature and Record
• Check the chilled water control actuator valve
• Check / inspect the chilled water coil

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 —