Maintenance of Air Handling Unit
OBJECTIVE: To lay down a procedure for the Maintenance of the Air Handling Unit
SCOPE: This SOP applies to the Air Handling Unit.
RESPONSIBILITY: Technical Supervisor / Engineer
ACCOUNTABILITY: Sr.Executive / Manager
PROCEDURE :
Daily Maintenance
Check and ensure that the difference between the inlet and outlet temperature of chilled water is within the limit (4º to 8º C)
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 the Daily Check Sheet after the completion of each activity. If it is not O.K. put a cross (X) in the Daily Check Sheet indicating the reason in the remarks column.
Immediately inform the concerned 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 thereof.
Weekly Maintenance
Check the condition of the belt for wear, tear, and damage replace if damaged and clean the area with Cora cloth.
Clean the AHU and its surroundings with Cora cloth.
Ensure no air leakages from the rexine cloth connection.
Check and ensure free flow of water in drain pipeline, clean with compressed air if pipeline is jammed
Ensure no vibration from the system and correct 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 a cloth to clear off any belt rubber strains
Put a Tick mark in the Weekly Check Sheet.
Monthly Maintenance
Clean the 20m, 10m & 5m filters as per SOP, and replace the filter if any damage on the filter screen.
Regrease the motor and blower bearings.
Check and ensure the modulating motor function w.r.t. Proportional thermostat setting. (thermostat setting is 66ºF).
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 an air blower and ensure no control wires hang, tag the wires with a cable tag if it is hanging.
Put a Tick mark in the Monthly Check Sheet.
Quarterly Maintenance
Clean the chilled water coil strainers.
Clean the 20m, 10m & 5m filters as per SOP, and replace the filter if any damage on the filter screen. (Applicable to all Primary, secondary packing, dispensing, and quarantine AHUs only)
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 chemicals (shiny side or van clean).
Clean the contactors with CTC / CRC.
Put a Tick mark in the Quarterly Check Sheet.
Half Yearly Maintenance
Replace the 20u filter with a new filter if the pressure drops across the filters is more than the 14 mm of WC or any damage and ensure no gap between the filters and frame.
Check and ensure the CFM of the blower with anemometer to design parameters
Clean the outer surface of the cooling coils with wire brushes, compressed air, water, and cleaning chemicals (shiny side or van clean).
Check the dynamic balance of the blower by empty rotation, make it balance if any unbalance.
Clean the surface of the motor with Cora Cloth.
Ensure the cooling fan of the motor is properly aligned.
Clean the external surface of the blower.
Put a Tick mark in the Half Yearly Check Sheet.
Yearly Maintenance
Replace the 10u filter with a new filter if the 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 the 5u filter with a new filter if the pressure drop across the filters is more than 14 mm of WC or any damage and ensure no gap between the filters and frame
Check the motor/ blower bearings clearance with feeler gauges, and 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 the Yearly Check Sheet.
Forms and Records (Annexures)
Not Applicable
Distribution
Master copy – Quality Assurance
Controlled copies- Quality Assurance, Production, Quality Control
