What does this automatic transfer switch (ats) quarterly checklist cover?

14 items across 4 sections, covering controller and status, before the test, transfer test, enclosure. 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 electrical or facilities tech on the quarterly round, coordinated with whoever runs the generator so the building isn't dropped.

When in the schedule should this walk happen?

Every quarter, tied to the generator exercise since the transfer switch is what proves the generator actually picks up the load.

Why do these items ask for a photo?

10 of the 14 items call for photo evidence, 11 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 an automatic transfer switch (ats) quarterly inspection?

Generator exercised in no-load mode while the transfer switch itself never actually transfers, so a stuck mechanism goes unfound until an outage. Controller sitting in a fault or maintenance-lockout state for weeks because nobody reads the display. Engine-start and transfer time delays bumped during a service call and never returned to the commissioned values.

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.

Free checklist

Automatic transfer switch (ATS) quarterly maintenance checklist

A quarterly automatic transfer switch round is short on purpose: it catches the wear items that fail between annual services. This checklist is sized for a tech with a phone. Every item says what to look at and the photo that proves the round happened. Work is commonly verified against NEC (NFPA 70), NFPA 110, manufacturer's published instructions. Confirm the edition your authority having jurisdiction has adopted.

Start free with this checklist Download as PDF

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.

Controller and status

Controller display and source indicators read
Normal source present, controller in automatic, no active alarms or lockouts, source-available and switch-position lights matching reality.
Time-delay and pickup settings match the commissioned record
Engine-start, transfer and retransfer delays checked against the setup sheet, not just left at whatever the last tech entered.
Normal source voltage and frequency read on the controller
Each phase read on the display against the nameplate rating and the commissioned pickup and dropout settings, with any sag or imbalance noted.
Event log read for transfers since the last visit
Controller history checked for unplanned transfers, failed transfers and source outages, with each one traced before the switch is tested.
Exercise schedule confirmed on the controller that runs it
Exerciser day, time and load or no-load mode match the owner's plan, whether set in the switch or the generator controller, and the clock is right.
No photo

Before the test

Owner notified before the switch is tested
Building contact told when the switch will transfer and which loads it serves, so nobody is surprised by a blink or a run on the generator.
No photo
Life-safety loads handled under the owner's procedure
Emergency lighting, fire alarm, elevators or other life-safety loads on this switch identified, and the owner's procedure followed, including notice to monitoring.
No photo
Generator service ready with the set in auto
Whoever runs the generator confirms the set is in auto with no alarms before the switch is commanded; engine-side checks stay with the generator service.
No photo

Transfer test

No-load or exercise transfer observed end to end
Switch commanded to transfer and retransfer, mechanism moving fully to each position, position confirmed on the controller and by the mechanical indicator.
Emergency source voltage and frequency read while transferred
While on the emergency source, controller readings checked against the commissioned settings, and the switch holding position without chatter.
Switch back on normal with the controller in automatic
After retransfer and cooldown, switch on normal, controller in automatic, test switch released, no alarms, and the owner and generator service told.

Enclosure

Enclosure closed, sealed and clear
Door latched, gaskets intact, no water staining or rodent entry, required working clearance kept in front of the switch.
Nameplate, arc-flash and source labels legible
Switch nameplate, arc-flash label and the normal, emergency and load identification readable and matching the building's one-line diagram.
Manual operator and its instructions present at the switch
Manual operating handle in its holder or on the mechanism, and the manufacturer's instructions for de-energized manual operation kept with the switch.

What usually sends this back

The failures are almost always the evidence, not the work

Generator exercised in no-load mode while the transfer switch itself never actually transfers, so a stuck mechanism goes unfound until an outage.
Controller sitting in a fault or maintenance-lockout state for weeks because nobody reads the display.
Engine-start and transfer time delays bumped during a service call and never returned to the commissioned values.

Verified against

Common questions

6 answers

What does this automatic transfer switch (ats) quarterly checklist cover?: 14 items across 4 sections, covering controller and status, before the test, transfer test, enclosure. 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 electrical or facilities tech on the quarterly round, coordinated with whoever runs the generator so the building isn't dropped.
When in the schedule should this walk happen?: Every quarter, tied to the generator exercise since the transfer switch is what proves the generator actually picks up the load.
Why do these items ask for a photo?: 10 of the 14 items call for photo evidence, 11 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 an automatic transfer switch (ats) quarterly inspection?: Generator exercised in no-load mode while the transfer switch itself never actually transfers, so a stuck mechanism goes unfound until an outage. Controller sitting in a fault or maintenance-lockout state for weeks because nobody reads the display. Engine-start and transfer time delays bumped during a service call and never returned to the commissioned values.
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

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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 11 required photos exist. Approved walks roll into a branded turnover package with a tamper evident record behind every line.