Jumlah Beban Audit
Gabungkan pelbagai peranti dan mesin untuk menentukan jumlah kapasiti yang diperlukan. Penting untuk penentuan saiz panel dan perancangan infrastruktur.
Tambah Peranti Rangkaian
Daftar Beban Panel
Daftar Litar Aktif
*Pemutus litar yang disyorkan termasuk faktor keselamatan beban berterusan 125%.
Formula Pengiraan Beban
Jumlah beban menentukan arus yang ditarik, pemutus litar yang diperlukan, dan sama ada litar anda bersaiz selamat.
Jumlah Arus Litar
I = ΣWatts ÷ Voltage Jumlahkan semua beban pada litar dalam watt, kemudian bahagikan dengan voltan bekalan untuk mendapatkan jumlah permintaan arus.
Saiz Pemutus Litar (Peraturan NEC)
Breaker ≥ Total Amps × 1.25 NEC memerlukan beban berterusan (beroperasi 3+ jam) tidak melebihi 80% kapasiti pemutus litar — bersamaan dengan menentukan saiz pemutus litar pada 125% daripada beban.
How to Calculate Electrical Load
A load calculation determines how much current a circuit, panel, or service must supply to all connected devices. Accurate load calculations prevent overloaded circuits, nuisance breaker trips, overheated wiring, and fire hazards. They are also required by electrical codes before adding circuits or service upgrades.
The 80% Rule for Continuous Loads
Any load that operates continuously for 3 hours or more is a "continuous load" under the NEC. Continuous loads must not exceed 80% of the circuit breaker's rating. A 20A breaker can sustain no more than 16A of continuous current. This prevents breakers from operating near their thermal limit indefinitely, which reduces reliability and lifespan.
Types of Electrical Loads
- Resistive Loads: Electric heaters, incandescent bulbs, toasters. PF = 1.0. Current and voltage are in phase — easiest to calculate.
- Inductive Loads: Motors, fans, compressors, transformers. PF typically 0.7–0.9. Draw additional reactive current beyond what wattage suggests.
- Capacitive Loads: Certain electronic power supplies and long cable runs. PF leading. Less common in typical building loads.
- Non-Linear Loads: Variable speed drives, computers, LED drivers. Introduce harmonic currents that can cause overheating in neutral conductors and transformers.
Step-by-Step Load Calculation
- List All Loads: Include every device connected to the circuit or panel — lights, outlets, fixed appliances, HVAC, etc.
- Note Each Wattage: Use nameplate ratings. For receptacle circuits, NEC allows 180VA per outlet as a standard assumption.
- Classify Continuous vs. Non-Continuous: Apply the 80% rule only to loads running 3+ hours continuously.
- Sum the Total Amps: Divide total watts by supply voltage to get current. Add motor startup surge separately if needed.
- Select Breaker and Wire: Choose a breaker rated above your calculated load (with the 125% rule for continuous loads), and size wire to match using NEC ampacity tables.