SOP ON MAINTENANCE OF AIR HANDLING UNIT

  • OBJECTIVE : To lay down a procedure for Maintenance of Air Handling Unit.
  • SCOPE: This SOP is applicable to Air Handling Unit at Formulations II Service floor.
  • RESPONSIBILITY: Technical Supervisor / Engineer .
  • ACCOUNTABILITY: Head of Department and Head QA. 
  • PROCEDURE: 
  • Daily Maintenance :
  • Check and ensure that the difference between inlet and outlet temperature of chilled water is with in the limit (40 – 8C).
  • Check & ensure no unusual noise from the system.
  • Check for any air leakages from the plenum and inspection doors and correct if any.
  • Put a Tick mark ( √ ) in Daily Check Sheet as per Annexure – I after completion of each activity. If it is not O.K put a cross (X) in Daily Check Sheet indicating the reason in remarks column.
  • Immediately inform to the concern superior if it is not O.K (X) and take necessary corrective action as per the advice.
  • Any such deviations should be maintained in the Machine History Cord along with necessary corrective action and its complaints there of.
  • Weekly Maintenance: 
  • Check condition of the belt for wear, tear and damage and replace if damaged and clean the area with lint free cloth.
  • Clean the AHU and its surroundings with lint free cloth.
  • Ensure no air leakages from the connection.
  • Check and ensure free flow of water in drain pipeline, clean with compressed air if pipe line is jammed.
  • Ensure no vibration from the system and correct if any.
  • Check and ensure the panel doors are closed properly.
  • Check and ensure all the indication lamps are glowing, replace the lamps if not working.
  • Clean the motor and blower pulley grooves with cloth to clear of any belt rubber strains.
  • Put a Tick mark (√) in Weekly Check Sheet as per Annexure II and repeat the above steps.
  • Monthly Maintenance: 
  • Clean the  filters as per SOP, replace the filter if found any damage on filter screen. (Applicable to all Module AHUs only).
  • Re grease the motor and blower bearings.
  • Check and ensure the modulating motor function w.r.t. Proportional thermostat setting.
  • Check and ensure functioning of heaters in plenum w.r.t. control thermostat setting.
  • Check and ensure the dampers of supply, return and fresh air ducts are in the correct position.
  • Check the motor load current and record it.
  • Check and ensure the Isolator / Switch functioning.
  • Clean the control panel with air blower and ensure no control wires should hang, tag the wires with cable tag if it is hanging.
  • Put a Tick mark (√) in Monthly Check Sheet as per Annexure III and repeat the above steps.
  • Quarterly Maintenance: 
  • Clean the chilled water coil strainers.
  • Clean the filters as per SOP, replace the filter if found any damage on filter screen. (Applicable to all Primary, secondary packing, dispensing, quarantine  AHUs.).
  • Ensure no air leakages from ducts and plenum doors.
  • Ensure no chilled water leakages from pipe joints, and gauge connections.
  • Regrease the bearings of the motor and blower.
  • Clean the outer surface of the cooling coils with wire brushes, compressed air, water and cleaning chemical (shiny side or van clean).
  • Clean the contactors with CTC / CRC.
  • Put a Tick mark (√) in Quarterly Check Sheet as per Annexure IV and repeat the above steps.
  • Half Yearly Maintenance:           
  • Replace pre- filter with new filter if pressure drop across the filters is more than the 14 mm of WC or any damages and ensure no gap between the filters and frame.
  • Check and ensure the CFM of the blower with anemometer with respect to design parameters.
  • Clean the outer surface of the cooling coils with wire brushes, compressed air, water and cleaning chemical (shiny side or van clean).
  • Check the dynamic balance of the blower by empty rotation, make it balance if found any unbalance.
  • Clean the surface of the motor with lint free Cloth.
  • Ensure the cooling fan of motor is properly aligned.
  • Clean the external surface of the blower.
  • Put a Tick mark (√) in Half Yearly Check Sheet as per Annexure V and repeat the above steps.
  • Yearly Maintenance:           
  • Replace intermediate filter with new filter if pressure drop across the filters is more than the 14 mm of WC or any damages and ensure no gap between the filters and frame.
  • Replace sub- intermediate filter with new filter if pressure drop across the filters is more than the 14 mm of WC or any damages and ensure no gap between the filters and frame.
  • Check the motor/ blower bearings clearance with feeler gauges, replace the bearings if clearance is more than 0.1 mm.
  • Carry out the DOP, Particle count and velocity tests for 0.3 micron HEPA filters.
  • Ensure all the control wiring is neatly dressed condition. 
  • Check the panel earthing. 
  • Put a Tick mark (√) in Yearly Check Sheet and repeat the above steps.
  • Distribution Details: QA and Engineering,Production            .
  • REVISION:Due to change of organisation logo