Why systems get called back
A lighting control system that passes startup can still generate months of complaints. The pattern repeats from building to building: lights turn off on someone at their desk, a daylight zone pumps up and down at dusk, the warehouse sweep runs on a holiday when the second shift is working, and nobody can find the settings to fix any of it.
Almost none of those are hardware failures. They are configuration problems that nobody tested, because startup answers does it work? and only commissioning answers does it do what we designed? Our commissioning service page covers that distinction in depth.
The decision to get right is what your commissioning scope must include so the system doesn’t come back to you after move-in. Use the checklist as written, or hand it to your commissioning agent and ask which items they will cover. Our rule of thumb is simple: commission everything, even the parts that “just work.”
Before anyone climbs a ladder
Callbacks often start on paper. The pre-functional review catches them while they’re still cheap to fix.
- A written sequence of operations exists for every space type: what turns lights on, off, up and down, and what the occupant can override. If it doesn’t exist, write it before testing.
- Submittals match the design: sensor types and lenses, driver dimming interfaces, gateway counts, and any substitutions since bid.
- Sensor locations make sense on the furniture plan, not just the ceiling plan. A sensor above a future bookcase is a callback.
- Daylight zones are drawn with the sensor location and the fixtures each sensor controls.
- Schedules reflect real operating hours, including second and third shifts, weekends, holidays and seasonal changes.
- The device schedule is complete: every sensor, switch, driver and gateway has an address or label and a location.
- The network design is agreed with IT: segment, addresses, remote access and who owns credentials.
- Emergency lighting interfaces are identified, with the test procedure agreed in advance.
The functional checklist
Test each sequence through each of its states and record the result, not just the setting. “Delay set to 15 minutes” is a setting. “Lights off at 14 minutes 40 seconds after vacating” is a result.
| Item | What to check | Pass looks like |
|---|---|---|
| Occupancy sensors | Coverage from every workstation; delay; partial-on level | Lights stay on for a seated occupant; off within the designed delay once empty |
| Vacancy-only spaces | Lights never turn on automatically | Lights on only from the switch; off automatically when vacant |
| Manual controls | Every switch and keypad operates the zone on the drawings | Labels match zones; no orphan buttons |
| Daylight response | Dimming with high, medium and low daylight; transition speed | Proportional dimming; no visible hunting at dusk; recovery as daylight fades |
| High-end trim | Maximum output per zone | Measured illuminance meets the target at the trimmed level; trim survives a power cycle |
| Low-end and dimming range | Lowest dim level per fixture type | Stable output with no flicker, dropout or visible stepping |
| Schedules | After-hours sweep, holidays, shift changes | Sweep runs on time; warnings before off where designed; overrides time out |
| Overrides | Manual override during scheduled off | Override holds for its designed period, then returns to schedule |
| Receptacle control | Controlled outlets in listed spaces | Outlets lose power when the space is vacant or scheduled off |
| Exterior and parking | Photocell or astronomical clock; late-night reduction | Off in daylight; reduced late at night; on at dusk without gaps |
| Demand response | Test signal from the utility or BMS | Designed load reduction occurs and restores on schedule |
| Power loss recovery | Cut and restore power to a panel | Zones return to the correct state, not to full on |
| Integration points | Occupancy, energy and alarm points to the BMS or analytics | Points arrive with correct names, units and update rates |
Two rows deserve attention because they generate callbacks months later. Power loss recovery: many systems come back at full output after an outage, and stay there until someone notices. High-end trim: a trim that resets after a firmware update or power cycle quietly erases the energy savings you designed.
Trim and tuning
High-end trim sets each zone’s maximum output to what the space needs. It’s one of the most effective energy measures in a new LED building, and one of the easiest to undo.
- Measure illuminance with a calibrated meter at task height, at night, with the trim applied.
- Record the target, the measured value and the trim level side by side.
- Walk the space with the facility manager and one or two occupants. A trim level that occupants accept in the first week will last; one imposed on them won’t.
- Recheck trim after the first firmware update.
Integration and the network
Modern controls rarely stand alone. Before handover, confirm:
- Occupancy and energy points reach the building automation system or Lytbit Ledger with the right names and units.
- Time is synchronized across controllers and gateways, so schedules and logs line up.
- Default passwords are changed, and admin credentials are held by the owner.
- Remote access, if any, is documented and approved by IT.
- Firmware versions are recorded for every device type.
Handover: the records are part of the system
The configuration report and test logs are what keep a system working after the commissioning team leaves. Give the owner:
- A configuration report, in ANSI/NEMA C137.9 format where the platform supports it. DLC’s NLC 5.2 requirements add configuration reports in that format.
- Signed functional test logs with measured results.
- A plain-language Sequence Book for the facility team.
- A system database backup, stored where the owner controls it.
- A closed punch list, with retest dates.
- Training: one short session for the facility team, one for IT.
Common shortcuts, and why they come back
- Testing a sample instead of every zone on a new installation. Sampling is fine for a re-commissioning survey; it isn’t fine at turnover.
- Testing during the day only. Daylight response needs testing at different light levels, and some schedules only run at night.
- Leaving exterior lighting for later. Later becomes never, until a tenant complains about a dark parking lot in December.
- No retest after fixes. A fix that isn’t retested isn’t closed.
The same checklist works on existing buildings
Re-commissioning a system that has been in service for a few years uses the same list in a different order. Start with the records: is there a sequence of operations, a configuration backup, a device schedule? Usually some of it is missing, and finding out what is missing is the first result.
Then sample representative spaces, such as a few private offices, a conference room, a daylight zone and an exterior circuit, and run the functional tests on them. The failures tell you where to look next. In occupied buildings the usual findings are sensors blocked by furniture that arrived after commissioning, overrides that quietly became permanent, holiday calendars nobody updated, and daylight sensors recalibrated by someone with good intentions and no meter. Each is cheap to fix once it is found. If the platform itself is no longer supported, the fix is a migration plan rather than a punch list.
What we’d do
For a new building or major renovation anywhere from Tupelo to Huntsville, our approach looks like this:
- Write or review the sequence of operations during design, and build a test script from it.
- Put functional testing in the specification, with the deliverables above named explicitly.
- Review submittals against the sequences and the furniture plan.
- Test every zone with a two-person crew, after hours where occupants would be disturbed.
- Fix and retest until the punch list is closed.
- Hand over the records in a format you own.
- Come back after a season to recheck trim, delays and daylight response once the building is fully occupied.
The codes require a minimum; our post comparing ASHRAE 90.1-2022 and the 2024 IECC covers what that minimum is. For systems already in service, our seven-campus school district scenario shows how re-commissioning works at scale. If you aren’t sure whether your building needs full commissioning or a lighter pass, a Baseline Assessment includes a sample functional test of representative spaces and a recommendation.
Filed under: commissioning · functional testing · checklist · high-end trim · ANSI/NEMA C137.9
