Life Support Track: HVAC, Cooling, Water and Power · Module 4 of 4 · about 15 min
Electrical safety and backup power
Every life support system runs on power, and power is where techs get hurt. NFPA 70E is the standard most U.S. employers use for electrical safety in the workplace, and OSHA rules require protecting workers from electrical hazards. The first rule is to put equipment in an electrically safe work condition before working on it: de-energize, lock out and verify.
Test before touch. Check your meter on a known live source, test the circuit, then check the meter again. Only then treat it as dead. Arc flash, the explosive release of energy from a fault, can burn and blind people even without contact, so energized work needs justification, a permit and arc-rated PPE.
Critical sites have layers of backup. An uninterruptible power supply (UPS) uses batteries to carry the load instantly when utility power drops. An automatic transfer switch (ATS) moves the load to a generator once it starts. The generator runs until utility power returns.
Backup that is never tested is a guess. Sites run generator and transfer tests on a schedule, check battery health and fuel, and write down what happened. The day the grid goes down is not the day to find out the generator will not start.
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Module quiz
5 questions, 4 correct to pass. You'll see what you missed and why, and you can retake it.