The purpose of this method statement is to define the step by step method to implement the correct practices for the pre-commissioning & commissioning of Close Control Unit 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.
Tools Required
- Digital Multimeter
- Clamp Meter
- Tachometer
- Anemometer
- Flow Hood Kit
- Digital Thermometer
- Psychoro meter
Quality Control At Site
In general, it shall be ensured by site mechanical engineer that product manufacturer’s recommendations are followed all the time, main contractor shall further oversee the Pre-commissioning and commissioning activity as per the approved method statement for Start-up and Commissioning of Closed Control Units. The Closed Control Units shall be tested and commissioned by manufacturer or supplier representatives while respective contractor shall monitor the work progress.
Commissioning Procedures
Mechanical:
- Carefully inspect the unit and check the installation is complete.
- Check and ensure the shipping bolts / clamps are removed.
- Check tightness of all nuts / bolts, screws, fasteners, rubber vibration isolators etc. as applicable
- Check all piping is completed.
- Check the duct work connections are complete as per approved shop drawings / details.
- Ensure the cooling coil and all interiors of CCUs are clean and free from foreign material.
- Check the fan rotator freely by hand and the direction of rotations on initial startup.
- Ensure the provision of cleanout.
- Ensure correct slope of the drain tray in the direction of drain pipe connection.
- Ensure flow test to ensure the water is drained out completely.
Electrical
- Ensure the connected cables have been tested and verify the test reports.
- Check all terminations are complete and tightened as required.
- Check the cabling / wiring including grounding is completed and dressed neatly for thermostat.
- Ensure all identification and labeling is completed.
- Check the isolator is fixed close to the Split Units for emergency power shut-down.
- Ceck the cabling / wiring including grounding is completed and dressed neatly.
Start Up and Test Preparation
- Check the line voltage before energizing the power.
- Switch ON the power.
- Verify for the proper operation of the Closed Control Units motor.
- Measure the current drawn (amperage) by Closed Control Units and record the same.
- Verify proper operation of the thermostat, supply air temperature and Humidity sensor.
- Check for any abnormal noise and vibration on startup. Rectify as / if required.
- After about an hour’s operation, check that all nuts / bolts, screws, clamps etc. are tight and secure.
- Measure the total airflow delivered by the Closed Control Unit check against the design flow and records the same in the approved format.
- Record the CCU data in the commissioning format.
- Ensure compliance to the manufacturer’s instruction as applicable.
Safety Requirements
- Safety precautions shall be followed as per the established Project Safety Plan.
- Only experienced and skilled technicians shall be engaged for carrying out Start-up and Commissioning of Close Control Units.
- Safety Guards shall be in place and secured prior to start-up.
- Cable test reports shall be verified prior to energisation.
- Appropriate Warning signs and tapes shall be placed during start-up and commissioning as required.
- All PPE shall be worn as appropriate according to the nature of the job.