# Is there a breaker that trips when the power goes out?

**URL:** https://boards.straightdope.com/t/is-there-a-breaker-that-trips-when-the-power-goes-out/1003255
**Category:** Factual Questions
**Created:** [June 24, 2024, 5:43am UTC](https://boards.straightdope.com/t/is-there-a-breaker-that-trips-when-the-power-goes-out/1003255 "2024-06-24T05:43:44Z")
**Posts on this page:** 1
**Showing post:** 12

<div class="post-metadata">

### Author: ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)
#### Post date: [June 24, 2024, 2:36pm UTC](https://boards.straightdope.com/t/is-there-a-breaker-that-trips-when-the-power-goes-out/1003255/12 "2024-06-24T14:36:19Z")

</div>

Circuit breakers are not designed to protect from voltage surges. They only trip quickly for very high currents. [I explained the time it takes for a circuit breaker to trip in this post.](https://boards.straightdope.com/t/how-much-current-does-a-refrigerator-use/993873/4)

We are assuming that the technician provided the OP with a correct explanation. A surge might take out the control board of an A/C unit, but that is repairable (although expensive - for an old enough system it might make sense to replace rather than repair). Damage requiring replacing the whole system sounds like a motor burned out due to a brownout (period of voltage too low for a motor to run but high enough to cause the stalled motor to burn out) rather than a surge.

---

_[View the full topic](https://boards.straightdope.com/t/is-there-a-breaker-that-trips-when-the-power-goes-out/1003255)._