One question from the early shift. The answer names its four sources.
Early shift, 07:14
Why is line 3 down?
MINERVA
What was measured
Bearing 1 Bearings 2 to 4
RMS per bearing · 24-hour average · 13 to 20 July
- Bearing 1 maximum
- 0.725 g single reading
- Readings flagged
- 44, from 17 July on
- Bearings 2 to 4
- 0.11 g at most
What the plant has on file
Maintenance instruction WA-L3-014, revision 4, effective 21 Jan 2026, filed in the document store, never in a time series.
| Level | Reading | Action |
|---|---|---|
| Normal | up to 0.12 g | observe the trend |
| Warning | above 0.12 g | trend review, shift log |
| Alarm | above 0.25 g | notify maintenance, order spare bearing |
| Shutdown | single reading above 0.40 g | immediate stop |
How the diagnosis comes about
| Trait | Measured | Documented damage pattern |
|---|---|---|
| Progression | RMS rising steadily over days | rising RMS |
| Bearings | only bearing 1 abnormal, 2 to 4 in band | exactly one bearing |
| Peaks | increasing isolated peaks | increasing isolated peaks |
The vibration monitor shut the line down at 07:10. The progression at bearing 1 is an outer race defect: remove, inspect, document the finding. Spare bearing Rexnord ZA-2115, replace as a set only.
What I cannot tell you
Confirming this needs a frequency analysis of the raw signal. In normal operation only condensed readings are archived; the raw signal for this bearing sits on the probe and is available through the API.
4 sources used ▾
- [1]Maintenance instruction WA-L3-014 · p. 1–2
- [2]Test rig bearing documentation · p. 2
- [3]Time series vibration_rms · bearings 1 to 4
- [4]Event log line 3 · 20 July, 07:10
