The purpose of this method statement is to define the step by step method to implement the correct practices for the Testing & Commissioning Of Starter Panels Variable Frequency Drives VFD’s 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 / EQUIPMENT:
Following tools shall be arranged before start of the activity,
- Portable Hand tools
- Step Ladder
- Insulation Resistance tester
Precommissioning Procedure for Starter Panel / VFD
Ensure that the Starter panel installation is complete and mechanical completion is approved & all the comments on the installation inspections are incorporated. Ensure that no damage has occurred to the Starter panel. Repair / replace damaged components, if any.
- Ensure that the tagging is complete & the starter panels/VFDs are identified location wise & service wise.
- Check & record insulation resistance values of all incoming & outgoing power wiring / cabling.
- Ensure that all the incoming & outgoing cables / wires have been terminated to their respective equipment with proper polarity.
- Ensure that all BMS wiring are completed.
- Ensure that the cable dressing is complete inside the starter panel.
- Ensure that all control wiring is done as per the approved scheme and terminated properly.
- Ensure that required jumper is provided as per the wiring diagram.
- Check the ratings of all MCCBs / MCBs are as per approved drawings and load schedules.
- Check the ratings of ELR as per approved drawings.
- Ensure all the wiring terminations are tight.
- Ensure the ratings of all protective fuses are correct.
- Check the manual operations of door mounted switches, push buttons, etc.
- Check the earthing connections for tightness.
- Check the overload relay settings to respective load fed by the starter panel / VFD.
- Check the ratios of CTs and ensure that is matching with relays / meters feeding to.
- Check the connection to exhaust fan.
Insulation Resistance Test
- Check the tightness of connections.
- Clean all the supporting insulators.
- Isolate the cables on incoming and outgoing side.
- Apply a megger voltage of 1000 Volts DC between Phase ‘R’ to earth for 1 Min with Phase ‘Y’, ‘B’ & ‘N’ shorted & earthed and record the values.
- Similarly continue the test and record the values for the other phases.
- Compare the results with the Factory Test Report.
- Check the earth loop impedance.
Commissioning Procedure for Starter Panel / VFD
- Ensure that all pre-commissioning checks have been completed successfully.
- Keep all the Isolators / Switches in ‘Off’ condition.
- Check the phase sequence
- Measure the Incoming Voltage.
- Switch ‘ON’ all control MCBs.
- Check the healthiness of all control fuses and rack into the base units.
- Remove the outgoing power cable / wiring connections.
- Check the operations of selector switches and meters.
- Check the operations of Push buttons and related sequential operations.
- Check the operations of Timers, Controllers and ensure the proper functioning and sequence.
- Check the proper functionality of all door mounted components.
- After ensuring the proper control sequential checks, switch ‘off’ the main incoming isolator.
- Reconnect the outgoing power cables / wires after ensuring the polarity of connections in panel end & equipment end.
- Checks for the proper tightness of connections.
- Keep all the switches in ‘OFF’ condition.
- Switch on the incoming power supply.
- Turn ‘On’ the required selector switches for manual operations.
- Observe the proper functions and sequences of operations of connected equipment.
- Check the direction of rotation of motors, if wrong, swap connections as required.
- Turn ‘Off’ the manual operations through push button / selector switch.
- Now ‘On’ the Starter panel in Auto mode & give the remote signal.
- Observe the proper function and sequences of operations of the equipment.
- Record the required parameters.
- Check the incoming voltage & phase sequence before switching ‘ON’ the incomer.
- Check control supply and stop lock provision and operation.
- Check bypass starter operation with the motor disconnected.
- Check VFD operation with the motor disconnected, from the control keypad.
- Set parameters as required and record the parameters.
- Check VFD operations from keypad after connecting the motor, also check motor’s direction of rotation.
- Check bypass starter operation with the motor connected, also check motor’s direction of rotation.
- Check external (remote) control of the VFD & Bypass.
- Precommissioning check sheet for Starter Panel/VFD
- Commissioning check sheet for Starter Panel/VFD
- Precommissioning & Commissioning Plan for Electrical System
- Risk Assessment
- Manufacturer’s instructions