Free checklist
Standby generator set annual maintenance checklist
The annual standby generator service is the deep pass: the measurements, cleanings and tests a quarterly round doesn't reach. This checklist keeps the full service on record with the photos that make it defensible later. Work is commonly verified against NFPA 110. Confirm the edition your authority having jurisdiction has adopted.
The checklist
Every item, and the photo evidence it needs
The photo count on each row is what RTI would require before the item can be submitted. Work the list here and watch the gate hold, or load it into RTI and let it enforce the real thing.
Notice and shutdowns
Owner given notice of the load test and standby outage
Building management told when the set will be loaded and out of auto, and whether building load or a load bank will carry the test.
No photoEngine safety shutdowns tested by the manufacturer's method
Low oil pressure, high coolant temperature and overspeed shutdowns simulated as the manufacturer allows; the set stops and shows the right alarm.
Load and engine
Load bank or building load test run at rated capacity
Percentage of nameplate load reached and held for the documented duration, with readings recorded.
Coolant hoses, belts and radiator inspected
Hoses supple with no swelling or cracking, belts within tension spec, radiator fins clear of debris.
Coolant sample or condition tested
Freeze protection and inhibitor levels within range, no rust or oil contamination.
De-energized service
Set locked out and tagged for the de-energized work
Output breaker open, charger and starting circuit locked and tagged by each worker; the ATS run takes the procedure's temporary release (guards on, people clear), then the set is re-locked for terminations.
Engine oil and filter changed with a sample for the lab
New filter marked with the date and engine hours; oil sample sent for analysis and the lab report kept with the set's record.
Alternator insulation resistance tested and trended
Tested per the manufacturer with the regulator isolated, reading recorded and compared with last year's result, and a falling trend flagged.
Starting batteries load tested with PPE on
Face shield and gloves on, each battery load or conductance tested against its rating, and the install date on the case noted.
Fuel system
Fuel system and day tank inspected
Tank level gauges accurate, vent lines clear, fuel polished or sampled if age warrants it.
No photoFuel lines, filters and transfer pump checked
No weeping at fittings, filters replaced on schedule, transfer pump cycles correctly.
No photoFuel tank containment checked dry and clean
Sub-base rupture basin or day-tank containment free of fuel, water and debris, any leak sensor clean and free to move, and fuel found in the space traced to its source.
No photo
Transfer and connections
Automatic transfer switch exercised under simulated outage
ATS senses simulated utility loss, starts the set, transfers load, then re-transfers and cools down on retransfer.
Electrical connections and terminations torqued
Lugs, breaker terminals and grounding connections checked for heat marks, torque verified or resistance measured per the manufacturer, re-torqued only where found loose.
Set returned to service in auto after the annual
Guards and covers refitted, locks removed by whoever hung them, output breaker closed, controller in auto with no alarms, owner told.
What usually sends this back
The failures are almost always the evidence, not the work
- Load test run at a fraction of nameplate capacity and reported as a full test.
- Coolant hoses left original past their service life because the engine 'wasn't leaking yet'.
- ATS exercised in test mode only, never proven under an actual simulated utility loss.
Verified against
Common questions
6 answers
- What does this standby generator set annual checklist cover?
- 15 items across 5 sections, covering notice and shutdowns, load and engine, de-energized service, fuel system, and more. Each item spells out what the person walking the job is actually looking for, not just a box to tick.
- Who should run this inspection?
- The generator service lead, often coordinated with the electrical contractor for the ATS work.
- When in the schedule should this walk happen?
- Once a year, scheduled with building management since it typically requires a planned load transfer or bank load.
- Why do these items ask for a photo?
- 11 of the 15 items call for photo evidence, 15 photos in all. A checklist answer without the photo is a claim; the photo is what makes the record worth something in a dispute and lets a reviewer approve work without re-walking the job.
- What most often fails a standby generator set annual inspection?
- Load test run at a fraction of nameplate capacity and reported as a full test. Coolant hoses left original past their service life because the engine 'wasn't leaking yet'. ATS exercised in test mode only, never proven under an actual simulated utility loss.
- Can I use this checklist in RTI?
- Yes. Start a free RTI workspace, build this list as a checklist, and the Photo Gate holds the submit button until every mandatory item is answered and its photos are attached. Approved inspections roll into a branded turnover package with a tamper evident audit trail.
Related checklists
Run it with the Photo Gate
A checklist nobody can submit half-finished
Load this list into RTI, stick a QR tag on the area it covers, and the submit button stays locked until every mandatory item is answered and the 15 required photos exist. Approved walks roll into a branded turnover package with a tamper evident record behind every line.
See all 508 checklists · 6741 items and 5984 photo requirements in total.