Why Your Generator Test Log Matters as Much as the Test
To a surveyor or fire inspector, a generator test with no paperwork looks the same as no test at all. NFPA 110 requires a permanent written record of emergency power supply system (EPSS) inspections, tests, exercising, operation, and repairs, and it expects that record to be readily available. For hospitals and other CMS-certified facilities, 42 CFR 482.15(e) requires generator inspection, testing, and maintenance to follow NFPA 99, NFPA 101, and NFPA 110, so the log is how you prove it.
Common documentation gaps are easy to predict: a missing week, a monthly test with no load reading, a 36-month test nobody can locate, or a deficiency that was noted but never closed out. A consistent generator test log, filled out the same way every time, closes most of those gaps before a surveyor finds them.
This page gives you a free printable generator test log with six forms, plus an explanation of what each test requires and why each column is there. The print button prints only the blank forms.
What NFPA 110 Requires You to Record
NFPA 110 does not mandate a form. Its Annex A includes sample logs, but the format is up to you. What the standard sets is what must be documented and the minimum content of the record.
Under the 2010 edition of NFPA 110 (the edition referenced by the 2012 Life Safety Code that CMS enforces), Section 8.3.3 calls for a written schedule of routine maintenance and operational testing, and Section 8.3.4 requires a permanent record of inspections, tests, exercising, operation, and repairs. Section 8.3.4.1 lists what that record must contain at minimum:
- The date of the maintenance report
- Who did the work -- identification of the servicing personnel
- Problems found -- any unsatisfactory condition and the corrective action taken, including parts replaced
- Post-repair testing -- testing of any repair for the time the manufacturer recommends
In the 2016 edition, these record-keeping provisions moved to Section 8.5, which also says records must be made available to the authority having jurisdiction (AHJ) on request. The Minnesota Department of Health's generator guidance for health care facilities summarizes the same minimum contents and adds that the record must be kept on the premises.
Key Takeaway
Every entry in your generator test log should answer four questions: when was it done, who did it, what was found, and what was done about it. The forms below are built around those four questions.
Weekly Inspection Requirements
NFPA 110 Section 8.4.1 requires the EPSS, including its associated components, to be inspected weekly and exercised under load at least monthly. The weekly inspection is a visual and operational readiness check, not a load run. The Joint Commission's hospital Life Safety and Environment of Care document review tool lists the weekly EPSS inspection, including associated components and batteries, among the documents surveyors review under standard EC.02.05.07. Note that effective January 1, 2026, the Joint Commission consolidated the hospital and critical access hospital Environment of Care and Life Safety chapters into a single Physical Environment chapter, so hospitals should confirm the current standard number when labeling their logs. Other accreditation programs still use the Environment of Care numbering.
The code text does not spell out a weekly checklist item by item, so facilities typically build one from the manufacturer's instructions and the sample schedules in the NFPA 110 annex. The Minnesota Department of Health recommends that a weekly inspection cover at least:
- Fuel -- main and day tank levels, day tank float switch, piping and hoses, and tank vents
- Lubrication -- oil level and lube oil heater
- Cooling -- coolant level, jacket water heater, belts, hoses, and fan
- Exhaust -- condensate trap and signs of leakage
- Batteries -- corrosion, electrolyte level where applicable, and battery charger operation
- Electrical -- general condition of wiring, connections, and breakers
- Generator and engine -- debris, loose fittings, and any unusual vibration, leakage, noise, or temperature
The weekly form condenses these into six check columns; add any manufacturer-specific items in the notes column. For a full breakdown of what belongs at each interval, see our weekly, monthly, and annual generator maintenance schedule.
Monthly Load Test Requirements
The monthly exercise is the core of any generator test log. Under NFPA 110 Section 8.4.2 (2010 edition), diesel generator sets must be exercised at least monthly for a minimum of 30 minutes using one of two methods:
- Exhaust temperature method -- a load that maintains the minimum exhaust gas temperature recommended by the manufacturer
- Percent-of-nameplate method -- operation at normal operating temperature and at not less than 30 percent of the generator's nameplate kW rating
For example, a 500 kW generator would need to carry at least 150 kW during the monthly test to meet the 30 percent method. The Minnesota Department of Health notes that warm-up and cool-down time does not count toward the 30 minutes. Spark-ignited units (natural gas or propane) are handled differently: they are exercised monthly with the available EPSS load for 30 minutes or until water temperature and oil pressure stabilize.
The load rule exists because a lightly loaded diesel does not run hot enough to burn its fuel completely. Unburned fuel, carbon, and moisture build up in the exhaust, a condition called wet stacking that hurts performance and engine life. Recording kW and exhaust temperature shows the test was more than an idle run.
Other monthly details worth capturing:
- Cold starts. Load tests must include complete cold starts (NFPA 110 Section 8.4.4), meaning no pre-warming before the simulated outage.
- How the test was initiated. The test is started by simulating a power outage using the transfer switch test function or by opening a normal breaker; opening a breaker is not required (Section 8.4.3).
- Real outages can count. If the generator carries load during an actual outage or for peak shaving, that run may be substituted for a scheduled test, as long as the same record is kept.
Healthcare Facilities: 20 to 40 Days
NFPA 99 (2012 edition) requires generator sets in health care facilities to be tested 12 times a year, with no less than 20 days and no more than 40 days between tests. That is stricter than a simple "once a month," so a log that shows June 1 and July 25 is a finding even though both months have an entry. CMS Life Safety Code tag K918 reflects the same 20-to-40-day interval.
The Minnesota Department of Health recommends a fuller monthly record: nameplate kW and its 30 percent value, hour meter readings, oil pressure, operating and exhaust temperatures, kW load, the ATS used, cooldown time, and problems found. The forms below capture all of these, with the fixed values on the information sheet.
Monthly Transfer Switch Test Requirements
NFPA 110 Section 8.4.6 requires transfer switches to be operated monthly. The monthly test consists of electrically operating the switch from the normal (primary) position to the alternate position and back again. The Joint Commission document review tool lists monthly testing of all automatic and manual transfer switches, with results and completion dates documented, under EC.02.05.07.
Two points trip up many logs:
- Every switch needs its own entry. A facility with four ATSs needs four monthly records, not one. The 2016 edition of NFPA 110 also calls for rotating which ATS initiates the monthly generator test so the engine-start circuit on each switch is proven over time.
- The 10-second transfer time. The Life Safety Code requires emergency lighting loads to be picked up within 10 seconds, and NFPA 99 sets the same 10-second target for the life safety and critical branches in health care facilities. However, both NFPA 110 and NFPA 99 (2012) say the 10-second criterion does not have to be met during the monthly test. If it is not met monthly, the facility needs a process to confirm the 10-second capability once a year. Recording transfer time on every monthly entry is the simplest way to have that evidence ready.
NFPA 110 also sets minimum time delays that are useful to verify on the log: at least 1 second on engine start, at least 5 minutes on retransfer to normal, and at least 5 minutes of unloaded cooldown before shutdown. See our automatic transfer switch maintenance guide for the full procedure.
Annual Load Bank Test When Monthly Loading Falls Short
Many generators are oversized for the building load they actually carry, often to handle large motor starts or future expansion. If a diesel unit cannot reach 30 percent of nameplate or the manufacturer's minimum exhaust temperature during monthly tests, NFPA 110 Section 8.4.2.3 still allows monthly exercise with the available load, but it adds an annual supplemental load test:
- At least 50 percent of nameplate kW for 30 continuous minutes, then
- At least 75 percent of nameplate kW for 1 continuous hour
- For a total of at least 1.5 continuous hours
The supplemental load is usually a portable resistive load bank. Any equivalent test load must be automatically replaced by the emergency loads if normal power fails during the test. The Joint Commission document review tool lists this annual test as the alternative when monthly tests do not reach 30 percent or the recommended exhaust temperature.
If monthly entries routinely show less than 30 percent load and no exhaust temperature reading, expect a surveyor to ask for the annual load bank record. For planning and procedure details, see our guide to load bank testing requirements.
The 36-Month Test for Level 1 Systems
Level 1 systems are those where a failure could result in loss of human life or serious injury. NFPA 110 Section 8.4.9 requires a Level 1 EPSS to be tested at least once every 36 months, continuously for the duration of its assigned class, with the test allowed to end after 4 continuous hours. Key requirements, as summarized by the Minnesota Department of Health:
- Initiation -- start the test by operating at least one transfer switch test function and then the remaining ATSs, or by opening the normal-power supply to all ATSs in the system being tested.
- Minimum load for diesel units -- at least 30 percent of nameplate kW (a supplemental load bank may be used to reach it) or a load that maintains the manufacturer's minimum exhaust temperature.
- Spark-ignited units -- the available EPSS load.
- Combining tests -- the 36-month test may be combined with one monthly test and one annual load bank test. When combined with the annual test, the first 3 hours run at the minimum 36-month loading and the final hour at no less than 75 percent of nameplate.
K918 commentary stresses that the 36-month test is a test of the whole system, including cold start and transfer of emergency loads, not simply a load bank run on the generator alone. Record hourly readings during the test and note on the record whether it was a standalone 36-month test or a combined test. Our 36-month 4-hour load test guide covers the procedure in detail.
How Long to Keep Generator Test Records
This is where many online checklists overstate the code. NFPA 110 does not set a fixed number of years. The 2016 edition says records are kept for a period defined by facility management or the AHJ, and a major EPSS training provider notes that NFPA 110 does not specify a retention period.
That leaves the decision to you, your AHJ, and your accreditor. Keep in mind that a retention period shorter than three years may leave you unable to show your most recent 36-month test. One industry commentator on K918 suggests keeping general records for about two years and 4-hour test records long enough to cover the last two tests. Treat that as a recommendation, not a code rule, and confirm your retention policy with your AHJ, state licensing agency, and accreditation organization.
Set the Retention Rule in Writing
Put your record retention period into your written EPSS maintenance and testing policy. Surveyors look more favorably on a documented, followed policy than on an unwritten habit, and it settles the question before anyone asks.
How to Fill Out Each Log
Each form is built so one person can complete an entry in a few minutes. Most columns are self-explanatory; these notes cover the ones that matter most in a survey.
Facility and Generator Information
Complete this once per generator and keep it as the cover sheet. Entering the nameplate kW and 30 percent of nameplate lets whoever runs the monthly test check the load against the target at the panel. Add the manufacturer's minimum exhaust temperature if you use that method, list every transfer switch by ID so ATS entries can reference it, and note the Level and Class so it is clear whether the 36-month test applies.
Weekly Inspection Log
Record fuel as a percentage or gauge reading for both the main and day tank. For the heater and charger column, confirm the jacket water heater is on and the battery charger shows no alarms. Write "OK" in the leaks column when nothing is found rather than leaving it blank; a blank cell reads as a skipped check.
Monthly Load Test Log
Note which ATS initiated the test so you can show rotation across switches. Minutes under load must be at least 30, not counting warm-up or cooldown, and the hour meter readings back it up. Write the load as both kW and percent of nameplate. Record exhaust temperature every month; it is required if you rely on the exhaust temperature method and useful evidence either way.
Transfer Switch Monthly Test Log
Use one row per switch per month. Record transfer time in seconds, and the retransfer delay and cooldown in minutes; both should be at least 5 minutes. Note any hesitation, noise, or alarm in the last column.
Annual and 36-Month Test Record
Identify the test type (annual load bank, 36-month, or combined) and write out each load step, for example 50 percent for 30 minutes then 75 percent for 60 minutes. Record the total continuous duration and load source, and attach the technician's detailed report with readings.
Deficiencies and Corrective Actions
This form closes the loop NFPA 110 requires: the unsatisfactory condition, the corrective action and parts replaced, and testing after the repair. An item with no corrected date is a red flag, so review this page at every monthly test.
Keeping Your Generator Test Log Survey-Ready
A complete log is only useful if you can hand it over quickly. The Joint Commission notes in its document review tool that its Life Safety surveyor starts reviewing documents soon after arriving. Paper or electronic, the goal is the same: complete, legible, and easy to find.
Paper Logs
Paper works well for facilities with one or two generators:
- Keep the binder in a fixed place, with a copy of the information sheet on top and forms filed by year.
- Use ink and initial every entry. Correct mistakes with a single line and initials rather than erasing.
- Attach vendor reports for load bank, 36-month, and repair work directly behind the matching log page.
- Scan completed pages monthly. The K918 commentary cited below suggests keeping both a paper set and an electronic set so a single lost binder cannot erase your history.
CMMS and Electronic Logs
A computerized maintenance management system (CMMS) or remote monitoring platform can schedule tasks, send reminders, and flag a test about to fall outside the 20-to-40-day window. A few cautions:
- Make sure the fields match this log. A work order marked "complete" with no kW, run time, or exhaust temperature does not prove the monthly requirement was met.
- Confirm you can print or export on demand. Practice producing a 12-month report before a survey.
- Keep vendor PDFs attached to the work orders they support.
Whichever method you use, assign one person to review the log every month for missed entries, readings below 30 percent, overdue deficiencies, and the date of the last 36-month test. For a broader pre-survey review, pair this log with our generator compliance checklist for facility managers. Healthcare facilities should also review the Joint Commission and CMS emergency power requirements.
Watch the Transitions
Transitions are a risky time for records: a new service vendor, staff turnover, or a switch from paper to software can all leave a gap. Overlap old and new systems for at least a month and confirm nothing was dropped.
Printable Generator Test Log Forms
Print as many copies of each form as you need. The weekly form holds six weeks per page, so most facilities print nine pages per generator per year. Each monthly load test page covers six months, so print two per generator per year. For transfer switches, print enough pages for one row per switch per month.
Facility and Generator Information
| Field | Value |
|---|---|
| Facility name | |
| Address | |
| Generator ID and location | |
| Manufacturer, model, serial number | |
| Nameplate rating (standby kW) | |
| 30 percent of nameplate (kW) | |
| Fuel type | |
| EPSS Level and Class | |
| Manufacturer minimum exhaust temperature | |
| Transfer switch IDs and locations | |
| Date placed in service | |
| Service vendor and phone | |
| Log period (year) |
Weekly Inspection Log
| Date and time | Fuel level (main / day tank) | Oil and coolant levels OK | Block heater and battery charger OK | Battery voltage and condition | Leaks, belts, hoses, exhaust | Initials and notes |
|---|---|---|---|---|---|---|
Monthly Load Test Log
| Date and ATS used to start | Hour meter start / stop | Minutes under load | Load kW (% of nameplate) | Exhaust temp | Oil pressure / coolant temp | Initials and issues |
|---|---|---|---|---|---|---|
Transfer Switch Monthly Test Log
| Date | ATS ID and location | Transfer time (sec) | Retransfer delay (min) | Cooldown (min) | Result (pass / fail) | Initials and notes |
|---|---|---|---|---|---|---|
Annual and 36-Month Test Record
| Date | Test type (annual / 36-month / combined) | Load steps (% and minutes) | Total continuous duration | Load source (building / load bank) | Result and report attached | Performed by (name, company) |
|---|---|---|---|---|---|---|
Deficiencies and Corrective Actions
| Date found | Equipment | Condition found | Corrective action and parts replaced | Date corrected | Post-repair test | Verified by |
|---|---|---|---|---|---|---|
Conclusion
A generator test log needs to be complete and consistent, not elaborate. Record every weekly inspection, monthly load run, and transfer switch operation, plus the annual load bank and 36-month tests where they apply, and close out every deficiency with a retest. Health care facilities should hold monthly tests to the 20-to-40-day window, and every facility should confirm its retention period with its AHJ and accreditor. For the full set of requirements behind these forms, see our NFPA 110 emergency generator compliance guide.
Sources and References
- 42 CFR 482.15 -- Condition of participation: Emergency preparedness -- Legal Information Institute, Cornell Law School. https://www.law.cornell.edu/cfr/text/42/482.15
- Inspection and Testing of Emergency Generators -- Minnesota Department of Health (rev. June 2024). https://www.health.state.mn.us/facilities/regulation/engineering/lscgensets24.pdf
- Hospital Life Safety and Environment of Care Document List and Review Tool -- The Joint Commission. https://digitalassets.jointcommission.org/api/public/content/29635f929b954b6c93beed7ed2a7816b?v=8ca3c82b
- Emergency Power Supply Systems (EPSS) -- CMS and NFPA 110 Compliance -- MGI EPSS, via Healthcare Facilities Management Society of New Jersey. https://hfmsnj.org/wp-content/uploads/2022/06/42-CFR-482-Requirements-for-EPSS-CMS-and-NFPA-110-Compliance-30-May-20.pdf
- Complying with Inspection, Testing and Maintenance for Electrical Systems -- Health Facilities Management magazine. https://www.hfmmagazine.com/articles/4461-complying-with-inspection-testing-and-maintenance-for-electrical-systems
- K-918 Essential Electric System Maintenance and Testing -- Generator Help Online. https://generatorhelponline.com/k918-essential-electric-system-maintenance-and-testing/
- K918 Electrical Systems -- Essential Electric System Maintenance and Testing (commentary) -- Generator Help Online. https://generatorhelponline.com/wp-content/uploads/2021/12/K-918-Essential-Electric-Systems.pdf
- Understanding NFPA 110 Generator Testing Requirements -- MGI EPSS. https://www.mgiepss.com/blog/understanding-nfpa-110-generator-testing-requirements
- Wet Stacking and How to Eliminate It -- Generator Source. https://generatorsource.com/generator-service/wet-stacking-and-how-to-eliminate-it/
- Joint Commission Standards Receive Significant Updates -- American Society for Health Care Engineering. https://www.ashe.org/joint-commission-standards-receive-significant-updates
