Engineering inputs
Set the engineering assumptions and design parameters.
Power and cable inputs
m
V
W
AWG
°C
Ω
%
V
Engineering results
Review calculated capacity, limits and design checks.
Calculated result
Estimated remote voltage— V
—POE CABLING TOOL
Evaluate remote power delivery for cameras, wireless APs, access control and other PoE devices at real cable lengths and temperatures.
Set the engineering assumptions and design parameters.
Review calculated capacity, limits and design checks.
Use the calculator to compare conductor gauge, total channel length, connector resistance, cable temperature and two-pair or four-pair delivery before installing a PoE camera, Wi-Fi access point, PTZ camera or access-control device.
Device DC load is divided by conversion efficiency to estimate power at the remote PoE input. A quadratic equation then solves current and voltage together. Cable-loss percentage is I²R loss divided by source power, equal to remote PoE input plus cable loss.
The AWG table represents conductor resistance at 20°C and the engine applies a 0.393%/°C correction. Enter one-way channel length; the formula models both polarities and adds the entered connector resistance as a complete loop value.
Four-pair delivery reduces ideal resistance by sharing current across more conductors. Real current can be uneven because of DC resistance unbalance. Cable bundles and high-power PoE can raise conductor temperature, so use a measured or conservatively estimated cable temperature rather than ambient temperature alone.
This tool does not perform IEEE detection, classification, Autoclass, LLDP, inrush or interoperability testing. A passing voltage result cannot prove that a PSE allocates the required class or that the PD starts successfully; check certified equipment specifications and test the complete channel.
Enter the total one-way copper channel length from PSE to PD, including horizontal cable and patch cords. Add the combined loop resistance of connectors and contacts in the separate resistance field.
Four-pair delivery places more conductors in parallel and reduces ideal loop resistance and current per conductor. The model assumes equal current sharing; it does not simulate pair-to-pair or within-pair DC resistance unbalance.
Not necessarily. Enter an estimated conductor temperature. Cable bundles, higher PoE current and installation conditions can raise conductor temperature above ambient, increasing resistance and voltage drop.
No. Detection, classification, inrush current, PSE power allocation and PD turn-on behavior are outside this steady-state model. Verify the PSE and PD types, classes and startup behavior together.
Device power is the useful DC load after the PD converter. The engine divides it by efficiency to obtain remote PoE input power. If your value is already measured at the PD Ethernet input, use 100% efficiency; cable-loss percentage is cable loss divided by source power.
This is a planning model, not a substitute for cable certification, electrical safety review or PSE/PD interoperability testing.
ENGINEERING WORKFLOW
Verify PoE source capacity, cable voltage delivery, rack power and cooling, then estimate telecom battery backup runtime.