Calculator Inputs
Example Data Table
These sample values show how different manufacturing assets can contribute to overall electrical demand and monthly energy usage.
| Equipment | Voltage (V) | Current (A) | Phase | Quantity | Hours/Day | Estimated Monthly kWh |
|---|---|---|---|---|---|---|
| CNC Mill | 415 | 18 | Three | 2 | 10 | 5922 |
| Injection Molder | 415 | 30 | Three | 1 | 12 | 4744 |
| Air Compressor | 415 | 12 | Three | 1 | 8 | 1898 |
| Conveyor Line | 230 | 9 | Single | 3 | 14 | 2286 |
Formula Used
1) Apparent Power per Machine
Single phase: kVA = (V × I) / 1000
Three phase: kVA = (√3 × V × I) / 1000
2) Electrical Input Power per Machine
kW input = kVA × Power Factor
3) Useful Output Power per Machine
kW output = kW input × Efficiency
4) Connected Load
Connected Load = kW input per machine × Number of Machines
5) Demand Load
Demand Load = Connected Load × Load Factor × Diversity Factor
6) Energy Consumption
Daily kWh = Demand Load × Operating Hours per Day
Monthly kWh = Daily kWh × Operating Days per Month
Annual kWh = Monthly kWh × 12
7) Cost Estimation
Monthly Energy Cost = Monthly kWh × Tariff
Monthly Demand Cost = Demand Load × Demand Charge
Monthly Total Cost = Monthly Energy Cost + Monthly Demand Cost
8) Carbon Estimate
CO₂ = Energy Use × Emission Factor
How to Use This Calculator
- Choose whether your equipment runs on single phase or three phase supply.
- Enter the operating voltage and input current for one machine.
- Add the expected power factor and machine efficiency values.
- Set load factor and diversity factor to reflect real production conditions.
- Enter runtime hours, active days per month, and machine quantity.
- Fill in the energy tariff, demand charge, and emission factor.
- Click Calculate Power Usage to view the result summary and chart.
- Use the CSV and PDF buttons to export the calculated output.
FAQs
1) What does this calculator estimate?
It estimates apparent power, real input power, useful output power, demand load, daily energy, monthly energy, annual energy, electricity cost, and carbon impact for manufacturing equipment groups.
2) What is the difference between connected load and demand load?
Connected load is the total installed electrical input power of all machines. Demand load adjusts that number using load factor and diversity factor to reflect actual simultaneous operating conditions.
3) Why is power factor important?
Power factor links apparent power to real electrical power. A lower power factor means more current is required for the same useful work, which can increase losses and utility penalties.
4) Why is efficiency included if current is already entered?
Efficiency is used here to estimate useful mechanical or productive output from the electrical input. It does not reduce billed energy when the entered current already represents input current.
5) When should I select three phase?
Choose three phase for industrial motors, compressors, molding equipment, and other factory assets powered by a three phase electrical system. Use single phase for smaller support equipment.
6) What is a demand charge?
Some industrial utility tariffs bill not only for energy consumed but also for peak demand. This calculator adds a simple monthly demand charge using the estimated demand load.
7) Can this replace meter readings?
No. It is a planning and estimation tool. For billing reconciliation, audits, or energy management projects, compare results with interval meter data or submeter measurements.
8) How can manufacturers reduce power usage?
Improve power factor, reduce idle runtime, stagger machine starts, optimize shift scheduling, maintain motors, repair compressed air leaks, and review tariffs against actual production patterns.