Electrical
PoE voltage drop and heat quick check
A field check for PoE voltage drop, bundle heat, conduit fill, and 802.3bt planning.
Direct answer
PoE checks need both voltage drop and heat awareness. Distance, cable gauge, bundle size, ambient temperature, and device class can all change whether a run is acceptable.
Inputs to capture
- Device power class and required wattage.
- Cable category, conductor size, and length.
- Bundle count and whether cable is in conduit.
- Ambient temperature and installation condition.
Decision flow
Check delivered voltage first, then heat and fill. A run can pass distance and fail the practical installation condition if the bundle is too dense or conduit is already crowded.
What to document
Record device class, cable type, one-way run length, bundle count, conduit fill assumption, calculated delivered power, and any derating assumption used.
FAQ
Is PoE limited to 100 meters?
Ethernet channel length is commonly planned around 100 meters, but delivered power and heat still need checking for high-power PoE and dense bundles.