TELECOM POWER & ENERGY
Estimate telecom AC feeder, breaker and DC branch planning current from load, voltage, phase, power factor, efficiency, headroom and derating assumptions.
Set the engineering assumptions and design parameters.
Review calculated capacity, limits and design checks.
The calculator estimates feeder and branch planning current from power, phase, power factor, conversion efficiency, headroom and a combined derating factor. It then shows the next common nominal current rating as a planning candidate.
Final breaker and conductor selection must also check conductor ampacity, installation method, ambient temperature, grouping, voltage drop, fault current, interrupting rating, trip curve, coordination/selectivity, earthing and local electrical rules.
The upstream feeder must supply more apparent and input power than the useful DC or equipment load when power factor and conversion losses are included.
Headroom represents planned growth and operating margin before installation and environmental derating are applied.
No. It is the next common nominal current rating above the calculated planning current. Final selection must verify conductor ampacity, fault current, interrupting rating, trip curve and coordination.
Enter the usable fraction after the applicable temperature, grouping, enclosure or installation effects have been assessed. Do not invent a derating value when the installation conditions are unknown.
Telecom sites often require both upstream AC feeder planning and downstream DC branch checks. The DC result provides a consistent current-and-headroom planning view, not a legal protection design.
ITU-T L.1200 series · IEC · ETSI
Use the project-applicable edition and local adoption. Content reviewed: 2026-09-10
ENGINEERING WORKFLOW
Move from site load through AC/DC distribution, rectifier sizing and operating diagnostics, battery backup, generator fuel, solar generation and facility efficiency as one energy engineering sequence.
