Safe, reliable operation of electrical systems is the ultimate goal of the commissioning process, and one of the key elements is NETA (InterNational Electrical Testing Association) testing.
Field acceptance tests ensure that the equipment will function as designed and that it meets the specifications and standards established by the manufacturer and design engineer. The recorded testing values serve as the foundation for the future operation and maintenance of the facility, as the client will use this information to establish baseline performance to allow for trending during future maintenance testing. Not only is it in the best interest of the commissioning authority to confirm that NETA testing is done (and performed correctly) for these reasons, it is also often a contractual obligation.
My background prior to commissioning was as a NETA test technician, so I wanted to share a personal experience about how critical this testing can be. We had a client with a 12.47 kV distribution, with generator back up protection both split over multiple paralleling switchgear lineups. The protection for the system had overlapping radial and differential protection, as well as power and voltage protective elements.
During the NETA testing, it was found that the differential protection was configured incorrectly, power protection elements did not have provisions for the wiring necessary to make them function, and there were multiple protection elements that either were not programmed properly or were not programmed at all. Fortunately, this was caught during the NETA testing, and the issues were able to be corrected prior to moving on to functional performance testing, saving all parties involved from a very embarrassing situation. Additionally, the issues identified would have affected the operation of the equipment, potentially creating a dangerous situation when energized that could have damaged equipment or caused injury.
When you are operating equipment under full load, standing next to it, is not the time to be wondering whether it is going to work as intended. This is really the goal of NETA: to establish the standards necessary to ensure that equipment is in good operating condition without damage, is correctly installed, and that the functions and physical attributes proven via testing are acceptable. There are two parts to this equation: one is the organization itself, and the second is the certified companies that actually perform the testing.
Since NETA is an established and accredited standards developer, it is common that project specifications will reference or list NETA standards as well as require that testing be performed by a NETA-accredited company. The benefit to the client is ensuring consistency in quality of work performed and the testing data received. It is strongly recommended that a commissioning authority obtain the current version of the NETA Acceptance Testing Standard and be familiar with it. By thoroughly integrating NETA testing into the commissioning process:
- The quality of work for the installation of electrical equipment is assured
- Function and performance of electrical equipment is confirmed
- Potential issues with equipment or installation can be identified prior to energization
- Electrical equipment baseline performance data is documented for future maintenance trending
Make sure to guarantee the safe, reliable operation of electrical systems that you commission and utilize NETA, a foundation of the commissioning process