METHOD STATEMENT FOR PRECOMMISSIONING & COMMISSIONING OF EXTRACT FANS

The purpose of this procedure is to define the step by step method to implement the correct practices for the pre-commissioning & commissioning of Extract Fans through the guidelines contained herein so as to ensure that the job execution complies with the project requirements and serves the intended function to satisfactory level.

Pre-commissioning Procedure for Extract Fans:

Ensure that the extract fan installation is complete and mechanical completion is approved. Ensure that no damage occurs between mechanical completion & pre-commissioning.

Repair all damages to the equipment finish paint. Check the fan is installed as per the approved shop drawings and manufacturer’s instructions. Check that the vibration isolators are fixed.

1. Check by hand that the fan is rotating freely.
2. Check duct connections and grilles as per approved shop drawing and respective method statement.
3. Check that the motor & the pulley are aligned & the belt tension is correct.
4. Check all VCDs and fire dampers are open.
5. Check for proper electrical power, control and earthing connections as per manufacturer’s recommendations. Field wiring to be pre-tested for continuity and insulation resistance.
6. Check the internal & external surface of the fan is cleaned.
7. Check the fan impellers are statically & dynamically balanced.
8. Set earth leakage and overload relays as per motor nameplate rating.

Commissioning Procedure for Extract Fans

1. Ensure that all the pre-commissioning checks are carried out successfully.
2. Start the fan for a moment & check the direction of rotation of the fan / motor is correct.
3. Upon ensuring correct direction of rotation, start the fan and run for 5 minutes.
4. Check for any undue vibration or noise.
5. Measure air flow in the main supply air duct and adjust, if required to set design value.
6. Similarly measure air flow in all the branches / outlets. Set to correct value by adjusting splitter damper, volume control damper, etc in the ducts.
7. Check any control / safety devices for proper functionality.
8. Check & record the currect & voltage on all phases.
9. Check & record the static head & total head.
10. Record all readings in the final performance check lis.
11. Check the interface with BMS & Fire alarm system.

ATTACHMENTS

• Pre-commissioning check sheet for Extract Fans
• Commissioning check sheet for Extract Fans
• Performance Test Record for Extract Fans
• Pre-commissioning & Commissioning plan for HVAC System
• Risk Assessment