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кВА в Амперы Калькулятор | Electrical Мощность Калькулятор

Convert kilovolt-amperes to amperes

Circuit Type

Результат

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Формулы

1φI = (kVA × 1000) / V

3φI = (kVA × 1000) / (√3 × V)

Краткая справка

kVA	@240V 1φ	@480V 3φ
25	104 A	30 A
50	208 A	60 A
100	417 A	120 A
500	2083 A	601 A
1000	4167 A	1203 A

Связанные

Understanding kVA to Амперы Conversion

Converting kVA (kilovolt-amperes) to амперы is essential when sizing electrical equipment like transformers, generators, circuit breakers, and cables. The kVA rating tells you the apparent power, while амперы tells you the actual current flow.

Why Конвертировать кВА в Амперы?

Equipment like transformers and generators are rated in kVA, but you need to know the amperage to size wires, breakers, and other protective devices. The conversion depends on whether you have a single-phase or three-phase system.

Single-Phase против Three-Phase

Single-phase systems have two wires (hot and neutral). Ток is simply: I = (kVA × 1000) / V

Three-phase systems have three hot wires carrying current 120° apart. The √3 (1.732) factor accounts for this phase relationship: I = (kVA × 1000) / (√3 × V)

Прак тическое применение

When sizing a transformer secondary breaker, convert the kVA rating to амперы at the secondary напряжение. For example, a 75 kVA transformer at 208V three-phase delivers: (75 × 1000) / (1.732 × 208) = 208 амперы per phase.

Часто задаваемые вопросы

For single-phase: Амперы = (kVA × 1000) / Вольты. For three-phase: Амперы = (kVA × 1000) / (√3 × Вольты) or (kVA × 1000) / (1.732 × Вольты). Simply Разделите the kVA на напряжение (and √3 for 3-phase) to get the current in амперы.

It depends on напряжение and phase. At 240V single-phase: 100,000 / 240 = 417 амперы. At 480V three-phase: 100,000 / (1.732 × 480) = 120 амперы per phase. At 208V three-phase: 100,000 / (1.732 × 208) = 278 амперы.

kVA is a unit of apparent power in electrical systems, equal to 1000 volt-amperes. It represents the total power flowing in a circuit, including both real power (kW) and reactive power (kVAR). Transformers, generators, and UPS systems are rated in kVA.

kW (kilowatts) is real power - the power that actually does work. kVA is apparent power - total power including reactive power. They're related by: kW = kVA × Мощность Factor. For purely resistive loads (PF=1), they're equal. For inductive loads (motors), kVA is always higher than kW.

In three-phase systems, the three voltages are 120° apart. When calculating total power from line напряжение and line current, the √3 (1.732) factor accounts for this phase relationship. It's derived from the vector sum of the three phase voltages.

Convert transformer kVA to амперы at the secondary напряжение, then size the breaker per NEC requirements. Primary breaker is typically 125% of primary FLA. Secondary breaker depends on application but often 100-125% of secondary FLA.

For wye (star) connections, line current equals phase current. For delta connections, line current is √3 times phase current. This calculator gives line current, which is what you need for sizing wires and breakers.

At 240V single-phase: 208 амперы. At 208V three-phase: 139 амперы. At 480V three-phase: 60 амперы. Remember that continuous loading should not exceed 80% of these values for transformer longevity.