What does the manufacturer reference establish?
The cited older Cummins control comparison lists Hours Run and Number of Starts as separate engine instrumentation features. It supports checking the identity of the displayed counter, not treating every controller display as the same instrument. Confirm the actual installed controller manual, counter definition, units and displayed resolution.
Commissioning Docs is independent and is not affiliated with Cummins. This article concerns evidence preparation, not a test procedure or a recommendation to operate a generator.
Sources: Cummins: PowerCommand generator controls feature comparison, older manufacturer reference
Which duration belongs in each evidence field?
Keep the approved test requirement beside the actual event record. A counter spanning the whole commissioning visit can include warm-up, unloaded running or another activity. A planned test window is not an observed result. Do not replace missing interval evidence with a subtraction that answers a different question.
| Record | Evidence to retain | What it cannot prove alone |
|---|---|---|
| Counter identity | Asset, controller, displayed field, unit and resolution | Required load condition |
| Start and finish readings | Values and observation times for the same unchanged counter | Continuity within the interval |
| Test window | Approved procedure and actual start and end events | All elapsed time was loaded running |
| Load intervals | Approved load evidence and its time basis | Approval merely because numbers exist |
| Interruptions | Event and reviewer disposition | That a paused test still satisfies the criterion |
| Final acceptance | Reviewer and supporting evidence references | An administrative total is technical sign-off |
What can a larger counter increase conceal?
Illustrative example. A fictional generator counter reads 120.0 hours before the visit and 122.0 afterwards. The difference is 2.0 hours. The approved test calls for a specific loaded interval, but the visit also includes unloaded running. Only 90 minutes of loaded running are supported by the controlled event evidence.
The counter total is not rewritten to 1.5 hours. Record 2.0 accumulated operating hours and 90 minutes of evidenced loaded running in separate fields. The commissioning reviewer decides whether the actual requirement is met. These invented values demonstrate evidence meaning, not an accepted test limit.
How should resets and coarse display resolution be handled?
If a counter decreases, is replaced or has an unexplained reset, preserve both observations and ask the responsible equipment owner for the explanation. Do not silently add an assumed rollover value. A display rounded to tenths of an hour cannot establish second-level timing just because the worksheet calculates more decimals.
Use the approved interval evidence to resolve the test requirement and retain any disagreement. The commissioning professional approves test acceptance. Engineering sign-off is performed only by the registered engineer on the job.
Common questions
What else should the bid team know?
Is elapsed wall-clock time the same as run time?
No. The equipment can stop or run under a different condition during the window.
Can a counter prove the load was correct?
No. Retain the approved load-condition evidence separately.
Should an unexplained reset be corrected in the worksheet?
Preserve it as a discrepancy and obtain the equipment owner's explanation.