FieldengNetworking & Communications
PoE Power Budget
Whether a PoE source budget covers connected PD loads. Not a PoE class lookup.
Networking & CommunicationsElectrical & Power
Whether a PoE source budget covers connected PD loads. Not a PoE class lookup.
App id: NET-09. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
available = budget × efficiency; remaining = available − Σ loadsInputs
| Name | Unit |
|---|---|
| PSE power budget | W |
| Efficiency (optional) | % |
| PD load 1 | W |
| PD load 2 (optional) | W |
| PD load 3 (optional) | W |
| PD load 4 (optional) | W |
| PD load 5 (optional) | W |
| PD load 6 (optional) | W |
Outputs
| Name | Unit |
|---|---|
| Total load (hero result) | W |
| Available usable power | W |
| Remaining budget | W |
| Budget utilization | % |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
Screening bands in the app: <70% · 70–90% · >90%.
| When | Observation | Severity |
|---|---|---|
Budget utilization < 0.7 | Reasonable apparent headroom | info |
Budget utilization ≤ 0.9 | Reduced PoE headroom | caution |
Budget utilization > 0.9 | Limited PoE margin | warning |
Assumptions
- Does not hard-code IEEE 802.3af/at/bt class behavior.
- Leave unused load fields blank. Default efficiency is 100%.
Provenance
- Simple PoE watt budget. Class, cable, and standard limits are not applied.