PoE Types, Classes and Power Reference Tables
Compare IEEE PoE type and class power references, distinguish PSE output from PD available power, and check negotiation and product power-budget details.
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PoE type power references
Power sourcing equipment (PSE) supplies the link; a powered device (PD) receives power. Source output and power available at the device are different quantities. Use the following common maximum reference values to read specifications, not as a guarantee for every port configuration.
| Type | Common standard reference | PSE output reference (W) | PD available-power reference (W) |
|---|---|---|---|
| Type 1 | 802.3af | 15.4 | 12.95 |
| Type 2 | 802.3at | 30 | 25.5 |
| Type 3 | 802.3bt | 60 | 51 |
| Type 4 | 802.3bt | 90 | 71.3 |
The reference values assume the applicable standard conditions. The actual power allowed to a device depends on the negotiated class, product implementation, channel, and operating mode. A “90 W” product headline is not a promise of 90 W at the PD input.
Class and allocation
| Class | Common PSE allocation reference (W) | Reading note |
|---|---|---|
| 0 | 15.4 | A legacy/default class context; verify the actual device and negotiation. |
| 1 | 4 | A lower-power class; source allocation and device available power remain different. |
| 2 | 7 | Read the PD maximum input requirement and documented class. |
| 3 | 15.4 | Not the same numerical quantity as the PD delivered-power reference. |
| 4 | 30 | Check the required type and supported negotiation. |
| 5 | 45 | A higher-power 802.3bt class context. |
| 6 | 60 | Check type, pair usage, and product operation. |
| 7 | 75 | Requires the documented higher-power implementation. |
| 8 | 90 | The highest class shown here; not a universal per-port setting. |
Type, class, physical-layer classification, LLDP behavior, single-/dual-signature support, and a vendor’s marketing name are related but not interchangeable fields. Verify which mechanisms the exact switch and PD support. Proprietary passive power arrangements are outside these IEEE reference tables.
Check the product and link
- Record the PSE model, supply configuration, total usable PoE budget, and specific port mode.
- Read the PD maximum input need, required type/class, negotiation, and accessory/heater operating mode.
- Check cable, connectors, channel performance, installation conditions, and the applicable cabling guidance.
- Confirm classification and actual operation with the documented commissioning/test method.
The existing PoE budget worksheet compares values you enter; it does not perform this standards negotiation lookup. Use the T568 pinout reference for conductor assignments and the test record for the observed link state and instrument evidence.