Commissioning Process: Pre-Commissioning vs. Commissioning

Overview

• Commissioning Process: Involves distinct stages with pre-commissioning and commissioning.
• Importance: Small issues in pre-commissioning can become significant later.

Pre-Commissioning

• Hand Over: Occurs after mechanical completion, marking the transition from construction to commissioning.
• Purpose: Confirm no damage during shipping and that on-site tests align with factory tests.

Key Concepts

• Factory Acceptance Testing (FAT): Testing by the manufacturer before shipping.
• Site Acceptance Testing (SAT): Field testing by vendor or commissioning team.
• Site Integration Testing (SIT): Tests equipment as a system in the field.

Mechanical Pre-Commissioning Activities

• Pipe Flushing: Ensures piping is free of blockages.
• Leak Testing: Checks fittings and joints for leaks.
• Pressure Testing: Confirms piping can maintain pressure.
• Verification of Rotational Equipment: Ensures mechanical balance and no excessive vibration.
• HVAC Testing: Balances airflow, ductwork, and controls.

Electrical Pre-Commissioning Activities

• Grounding and Bonding Checks: Measures resistance to ensure integrity.
• Cold Loop Checks and Mega Checks: Verify cable and conductor terminations and integrity.
• Hot Loop Checks: Confirm calibration of control loops.
• AC Phase Checks: Verify electrical phase installation.

Transformer and Electrical Tests

• Transformer Checks: Includes oil samples, winding resistance, and ratio measurements.
• Protection Relay Testing: Verifies relay inputs through primary and secondary injections.
• Interlock Verification: Confirms interlocks function correctly.
• AC and DC Hypot Tests: Measure dielectric resistance.
• Battery Discharge Tests: Confirm capacity during charge cycles.

Pre-Commissioning Completion

• Equipment is tested as standalone items.
• Known as vendor startup, each piece of equipment is confirmed ready for commissioning.

Commissioning

• Purpose: Tests equipment together as a system.
• Example: Chemical dosing skid with integrated components like pumps and controllers.
• Process: Verifies control of equipment as subsystems and their integration.

Key Differences

• Pre-Commissioning: Individual tests of equipment.
• Commissioning: System-level tests to ensure intended plant process.

Importance of Completeness

• Skipping tests leads to issues, e.g., debris in piping affects flow rates.
• Proper planning includes all necessary tests to ensure a functional system.

Additional Resources

• Free mini-course available online.
• Subscription recommended for updates on commissioning and startup processes.