Successful equipment testing outcomes start with the basics.
It is common for teams to focus on the complex portion of testing regimes, neglecting to get the basics right.
Most electrical equipment comes direct from factory having undergone rigorous testing as dictated by Routine test requirements, however an element of human interaction always exists and the human error element must be accounted for.
Most defects identified during testing are generally due to simple issues, impacting efficiency and costing time and money. Many problems can be avoided by ensuring some basic activities are included in the inspection and testing process.
- Check Labelling – all equipment must be labelled per approved design documentation. Correct labelling is vital to equipment and personnel safety during energisation and operation. Equipment labels are used as reference points for permits, operating instructions and work authorisations.
- Point to Point checks – one of the core verification tasks that often eliminates most if not all issues faced during further functional testing. Tests should be performed to ensure there are no interconnection of conductors between different circuits or short circuits between conductors. One of the most common issues identified during testing is incorrect terminations, mostly within control cubicles or where large number of terminals are grouped. The main cause can be attributed to parallax error – i.e terminations offset by one or two spaces.
- Verification of Circuit Polarity – incorrect circuit polarity can not only damage sensitive electronic equipment, it can also cause harm to personnel. Particular attention should be given to equipment that is manufactured overseas, where equipment wiring conventions are different from installation wiring.
- Confirmation of Terminal Tightness – often neglected due to the arduous verification process. Point-point and functional tests will not identify where connections are seated but not secured. Over time, loose terminations will eventually move and cause intermittent faults that are hard to diagnose. Generally, the only way to ensure circuit integrity is by performing a pull test, and running a driver across all terminals.
Several of the activities above form part of the minimum verification requirements listed in Section 8 of AS3000 – Wiring Rules. These should be implemented in an iterative approach and be considered fundamental to all testing plans.
As a final note, due to the personnel and equipment safety implications, always ensure CT secondary connections are reinstated as per design and never leave the secondary terminals open circuit. Improve efficiency and reduce costs of the equipment testing process by planning the work well and executing the basics. Contact the team 1300 360 545.
