# How do you calculate Copper Loss?

**URL:** <https://forumautomation.com/t/how-do-you-calculate-copper-loss/12160>\
**Category:** Electrical\
**Tags:** interviewquestions\
**Created:** [June 13, 2024, 3:25pm UTC](https://forumautomation.com/t/how-do-you-calculate-copper-loss/12160 "2024-06-13T15:25:50Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Rabert](https://forumautomation.com/user_avatar/forumautomation.com/rabert/32/6784_2.png) [@Rabert](https://forumautomation.com/u/Rabert)\
**Post date:** [June 13, 2024, 3:25pm UTC](https://forumautomation.com/t/how-do-you-calculate-copper-loss/12160/1 "2024-06-13T15:25:51Z")

</div>

Copper loss, or I²R loss, refers to the power loss caused by the resistance of copper windings in the electrical equipment such as

• **[Transformers](https://forumelectrical.com/what-is-over-fluxing-in-power-transformer/)**,

• **[Motors,](https://forumelectrical.com/three-phase-motor-testing-procedure/)** and

• **[Generators.](https://forumelectrical.com/8-step-by-step-guide-to-determine-generator-requirements/)**

 ![image](https://cdn.forumautomation.com/original/2X/5/552f61999cbc0f59f49909879dfb1eeff3ed45a6.jpeg)

## [color=#ff0000]Copper Loss Formula [/color]

It is calculated using the following formula:

**Copper loss = I2 x R**

Where,

I - Current flowing through conductor (A), and

R - Conductor’s Resistance (in ohms).

## [color=#ff0000]Steps for Calculating Copper Loss [/color]

**Step-1:** Measure or get the current that flows through the copper winding.

**Step-2:** Measure the resistance (R) of the copper winding. This can be measured using an ohmmeter or estimated using copper’s length, cross-sectional area, and resistivity.

**Step-3:** To calculate copper loss, use the following formula and substitute current and resistance values.

## [color=#ff0000]Solved Example [/color]

Consider a transformer winding with resistance of 0.5Ω & a current of 10 amps flowing through it.

Current (I): 10A.

Resistance (R): 0.5 Ω.

Copper loss = 10 x 10 x 0.5

Copper loss = 100 x 0.5.

Copper loss = 50 watts.

Thus, the copper loss is 50W

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