Commissioning — a building deliberately made to fail, repeatedly.
L4 and L5 exist to prove the facility survives failures. That means inducing them, on purpose, while people stand next to the equipment doing it.
Once equipment is energized, NFPA 70E applies to it — regardless of whether the project is complete or the certificate of occupancy has been issued. The equipment does not know the schedule. Full detail →
§ L1 through L5
Factory witness testing. Off site. Low site risk.
Delivery and installation verification. Rigging and materials handling risk.
Pre-functional / static testing. Megger, torque, continuity. The last phase where the gear is mostly dead.
Functional performance testing. The gear is live. Breakers operated, transfers performed, relays tested and deliberately mis-set to prove a trip. Highest electrical risk in the project.
Integrated systems testing. Full load bank, utility failure simulation, generator start and transfer — sometimes with IT load present.
Arc flash labels come from the final study, which is usually completed near the end of the project. Gear is therefore frequently energized for weeks before it is labelled — during exactly the period when unfamiliar people are working on it. A preliminary study with interim labels closes this, and it is cheap.
§ Controls that work
Daily energization status board at each electrical room. What is live, and who owns it.
Single written switching authority per system, per phase, with named alternates. If it is not written, the answer during an incident will be "each thought the other had it."
Defeat automatic operation before work — generator auto-start, ATS, automatic bus ties.
Qualified person verification for everyone entering a live room, including OEM and commissioning staff.
Physical demarcation under 1926.200, moved as the boundary moves.
The 130.2(A)(2) additional person. Commissioning is precisely where permitted energized work happens — and it now takes two people.
Onsite 70E for the Cx crew
Commissioning agents, electrical primes and operations staff, on the 2027 edition, before L4 starts.
Onsite training Get in touch