# SS-KPI-H-01 Substation hours below outage limits

> Substation hours below outage limits: < 60 h a year, judged on the month pro rata (≈ 4.9 h in 30 days); shorter windows report hours used. Substation KPI, Heatweb. Monitoring points, threshold and calculation.

| | |
|---|---|
| Element | Substation (SS) |
| Standing | Heatweb |
| Monitoring points | SS2 · 5 min · tFOff (sensor, else heat meter); SS5 · 5 min · sensor dpIndex |
| Threshold | < 60 h a year, judged on the month pro rata (≈ 4.9 h in 30 days); shorter windows report hours used |
| Calculation | Σ_i min(t_{i+1} − t_i, 1 h) over readings with tF < tF_min or dP < dP_min; tF and dP spans unioned. Offered as an alternative to KPI-04/05. Uses design/minFlowTempOff design/minDPIndex |
| Period | Monthly (pro rata) |

Part of the **Hours below outage limits (alternative to 04/05)** family.

## Discuss this KPI

Is the threshold right? Does the calculation match what you compute on your networks? [Comment on SS-KPI-H-01](https://github.com/heatweb/HNQAP/issues/new?template=kpi-comment.yml&kpi=SS-KPI-H-01&title=SS-KPI-H-01%3A%20), or report how it behaves on your data. Comments are public and are read before every revision.

## Machine-readable

This KPI is a row of [kpi-reference.json](/data/kpi-reference.json) (element `SS`, code `SS-KPI-H-01`). The [notation and rules](/kpis/#how-to-read-the-tables) that apply to every KPI are on the reference page.