# \#calculator **URL:** https://forumautomation.com/tag/calculator/102.md [Latest](https://forumautomation.com/latest.md) · [Categories](https://forumautomation.com/categories.md) · [Tags](https://forumautomation.com/tags.md) --- ## [4-20 mA to Percentage (%) Conversion Chart](https://forumautomation.com/t/4-20-ma-to-percentage-conversion-chart/14506)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [October 15, 2026, 3:51pm UTC](https://forumautomation.com/t/4-20-ma-to-percentage-conversion-chart/14506 "2026-10-15T15:51:53Z")
4-20 mA to Percentage (%) Conversion Chart --- ## [Three Phase Important Formulas](https://forumautomation.com/t/three-phase-important-formulas/14185)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [June 9, 2026, 8:25am UTC](https://forumautomation.com/t/three-phase-important-formulas/14185 "2026-06-09T08:25:14Z")
Essential three-phase electrical formulas used to calculate power, current, voltage, efficiency, and power factor in industrial and commercial systems. These formulas help engineers and technicians design, analyze, trou… --- ## [Calculate the wire size, MCB (Miniature Circuit Breaker) and ELCB (Earth Leakage Circuit Breaker) for a 20kW load](https://forumautomation.com/t/calculate-the-wire-size-mcb-miniature-circuit-breaker-and-elcb-earth-leakage-circuit-breaker-for-a-20kw-load/13863)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [January 30, 2026, 6:50pm UTC](https://forumautomation.com/t/calculate-the-wire-size-mcb-miniature-circuit-breaker-and-elcb-earth-leakage-circuit-breaker-for-a-20kw-load/13863 "2026-01-30T18:50:40Z")
Wire Size Calculation Step-1: Calculate Current Single phase: I = P / (V x PF) = 20000 / (230 x 0.8) ≈ 109A Three phase: I = P / (√3 x V x PF) = 20000 / (1.732 x 400 x 0.8) ≈ 36A Step-2: Apply Derating Factors Ambient … --- ## [Power Factor Calculation](https://forumautomation.com/t/power-factor-calculation/14452)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [September 28, 2026, 7:46am UTC](https://forumautomation.com/t/power-factor-calculation/14452 "2026-09-28T07:46:41Z")
Power Factor (PF) = Real Power (kW) ÷ Apparent Power (kVA) For a sinusoidal AC system, PF = cos φ, where φ is the phase angle between voltage and current. A lower power factor requires higher current to deliver the sam… --- ## [How to Calculate Transformer Full-Load Current (FLC)?](https://forumautomation.com/t/how-to-calculate-transformer-full-load-current-flc/14441)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [September 24, 2026, 6:27am UTC](https://forumautomation.com/t/how-to-calculate-transformer-full-load-current-flc/14441 "2026-09-24T06:27:54Z")
Calculator Transformer Full-Load Current A simple calculation every electrical engineer, technician, and maintenance professional should know: How much current can a 1500 kVA, 3-phase transformer deliver at 415 V? Let… --- ## [How to calculate kVAR from kW? Step-by-Step Calculation with Formula](https://forumautomation.com/t/how-to-calculate-kvar-from-kw-step-by-step-calculation-with-formula/14298)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [August 5, 2026, 11:27am UTC](https://forumautomation.com/t/how-to-calculate-kvar-from-kw-step-by-step-calculation-with-formula/14298 "2026-08-05T11:27:29Z")
Reactive power (kVAR) can be calculated from active power (kW) using the power factor of the electrical system. This calculation is essential for capacitor bank sizing, power factor correction, and electrical system desi… --- ## [Transformer Voltage Regulation Calculator](https://forumautomation.com/t/transformer-voltage-regulation-calculator/14249)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [July 11, 2026, 2:55am UTC](https://forumautomation.com/t/transformer-voltage-regulation-calculator/14249 "2026-07-11T02:55:29Z")
Transformer Voltage Regulation Calculator The \[url= Transformer Voltage Regulation Tool\]\[color=#1E00A3\] Transformer Voltage Regulation Calculator \[/color\]\[/url\] is an online engineering tool that calculates transformer v… --- ## [How to find RPM and Pole Pairs in Induction Motors?](https://forumautomation.com/t/how-to-find-rpm-and-pole-pairs-in-induction-motors/12441)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [August 14, 2024, 10:05am UTC](https://forumautomation.com/t/how-to-find-rpm-and-pole-pairs-in-induction-motors/12441 "2024-08-14T10:05:37Z")
Calculation \[color=#ff7700\] Parameter \[/color\] \[color=#1e00a3\] RPM (Revolutions per Minute) \[/color\] RPM is calculated by the formula: RPM = (120 × Frequency) / Number of Poles The frequency refers to the supply fr… --- ## [Battery Backup Time Calculation](https://forumautomation.com/t/battery-backup-time-calculation/13873)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [February 9, 2026, 2:56pm UTC](https://forumautomation.com/t/battery-backup-time-calculation/13873 "2026-02-09T14:56:55Z")
Basic Battery Backup Time Calculation Battery backup time calculation helps to calculate how long a battery system can supply power to a connected load. The calculation becomes more accurate as we include real world fac… --- ## [Amps to Watts at 120V (AC) Conversion Calculator](https://forumautomation.com/t/amps-to-watts-at-120v-ac-conversion-calculator/13092)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [March 16, 2025, 3:54am UTC](https://forumautomation.com/t/amps-to-watts-at-120v-ac-conversion-calculator/13092 "2025-03-16T03:54:21Z")
Converting amps to watts at 120V AC aids in calculating power usage in electrical circuits. Here’s the formula: Watts are calculated as amps multiplied by 120. Watts=Amps×120V Apply the fundamental formula to resist…