Electrical Systems Maintenance Checklist

Print the current one-line and pull the last two PM records from the CMMS. Cross-check any open work orders against the equipment list before energizing anything; deferred PMs from the prior cycle are a common gotcha.

Use the equipment-specific LOTO procedure card — generic procedures don't satisfy 29 CFR 1910.147. Each isolation point gets a personal lock; group lockboxes only with a designated authorized employee.

Use a CAT III/IV rated meter, calibration current. Live-dead-live test on every phase plus phase-to-ground. Capture a photo of the meter reading on each gear lineup as audit evidence.

Read the arc-flash label on each piece of gear and select PPE category for the highest exposure on this WO. Face shield, balaclava, and voltage-rated gloves with leather protectors — no exceptions for short tasks.

Rack out each breaker, inspect line and load stabs for arc tracking, pitting, or discoloration. Wipe contacts with approved solvent; replace any breaker showing carbon tracking on the molded case.

Image under load. Flag any connection more than 10°C above adjacent connections, or any absolute reading above 75°C. Save the IR images to the asset record in the CMMS for trending.

Inject secondary current and verify pickup, time-curve, and instantaneous trip against the coordination study. Settings drift after firmware updates and after vendor service visits — verify, don't assume.

Use a calibrated torque wrench to manufacturer-stamped values, not a generic table. Mark each verified connection with a torque-seal stripe so the next PM cycle can spot a backed-out lug at a glance.

Three-point fall-of-potential method on the main ground electrode. Target ≤5 ohms per NETA spec. Soil moisture varies seasonally — note the weather and compare to last cycle's reading.

Pull oil sample per ASTM D923 from the bottom drain valve into the lab-supplied syringe. Ship to the lab same-day; trace gases (acetylene, hydrogen) above Doble limits indicate arcing or thermal faults.

One-minute and ten-minute readings, calculate polarization index (PI ≥ 2.0 is acceptable). Discharge windings to ground for at least 4× the test duration before disconnecting leads.

Take readings at the drive end and non-drive end in horizontal, vertical, and axial directions. Compare velocity (in/sec) to ISO 10816 zone limits for the motor frame size. Trend month-over-month in the CMMS.

Soft-foot check first; alignment results are meaningless if the base rocks. Hold parallel and angular offset under 0.002" for direct-coupled motors above 1800 RPM.

Use the lift-truck inspection log; do not climb to fixtures with a damaged ladder. Match Kelvin and lumen output to the surrounding fixtures so the floor doesn't get a patchwork lighting profile.

NFPA 101 requires annual 90-minute load test plus monthly 30-second functional. Tag any fixture that drops below threshold during the run and replace the battery pack — don't recharge and re-test.

Loose I/O terminals are a leading cause of intermittent line-down events. Check field wiring at the I/O cards and at the field device end; common ground-loop issues live in the analog inputs.

NFPA 110 requires monthly exercise plus an annual load test at ≥30% nameplate for two hours. Wet-stacking from years of unloaded run-time shows up here as black exhaust and fuel dilution in the oil.

Simulate utility loss; verify open-transition transfer time stays under 10 seconds and re-transfer timer matches the spec. ATS contacts pit over time — visually inspect during the test.

VRLA strings degrade non-linearly; a string that ran 12 minutes last year may run 4 minutes this year. Replace at 80% of original runtime, not at outright failure.

Pull a bottom sample and check for water and microbial contamination. Diesel stored over a year benefits from polishing; biocide treatment is cheaper than a clogged injector pump during an outage.

Attach the IR images and reference the affected gear. Tag the connection in the field and segregate the WO until corrective action is verified by re-imaging under the same load.

Lock out the transformer and notify the plant manager same-day. Failed insulation requires either factory rewind or replacement; coordinate with utility for any temporary feed needed during outage.

Until repaired, the plant is on utility-only — escalate to operations leadership and post the temporary EAP variance. Generator vendors typically run a 5-10 business day lead time on emergency dispatch.

Close the PM work order in eMaint or Fiix with actuals — labor hours, parts consumed, and any deferred items routed to follow-up WOs. The signature attests the work was performed by a qualified electrician.

Each authorized employee removes their own lock — never another person's. Walk the shift handover with the incoming supervisor: any open NCRs, any equipment left out of service, any temporary feeds in place.