---
title: "Xingguang | Inrush and breaker sizing: why it trips on switch-on"
description: "LED inrush comes from charging the input capacitor: the peak can reach 20–60 times rated current for under 1 ms. A breaker trips on the let-through energy, so one fixture is fine and a row switched on together is not."
url: "https://www.xingguanglightingcn.com/en/spec/inrush-current-breaker-sizing"
lang: "en"
updated: "2026-10-28"
markdown: "https://www.xingguanglightingcn.com/en/spec/inrush-current-breaker-sizing.md"
---

[Home](https://www.xingguanglightingcn.com/en/) / [Selection by specification](https://www.xingguanglightingcn.com/en/spec/) / Inrush and breaker sizing: why it trips on switch-on

# Inrush and breaker sizing: why it trips on switch-on

LED inrush comes from charging the input capacitor: the peak can reach 20–60 times rated current for under 1 ms. A breaker trips on the let-through energy, so one fixture is fine and a row switched on together is not. Three workable fixes: use type C or D (magnetic trip at 5–10 and 10–20 times) rather than type B; keep a 16 A circuit to about 8–12 fixtures, checked against the driver I²t and the breaker curve; and stagger the switch-on or specify soft-start drivers. On site, energise the row in two halves — if the trip disappears it is inrush, not a faulty fixture.

[Get a Quote](https://wa.me/8613809877696)

## Key parameters

| Power | 100–240 W |
| --- | --- |
| Luminous flux | 13,000–31,000 lm |
| Mounting height | 6–10 m |
| Input voltage | 220–240 V |
| Frequency | 50 / 60 Hz |
| Allowed voltage drop | ≤ 3% end to end |
| Inrush current | about 30–60 A cold start per fixture, under 1 ms |
| Breaker sizing | type C or D; about 8–12 fixtures per 16 A circuit |

[Product family: High Bay Lights](https://www.xingguanglightingcn.com/en/product-categories/high-bay)

## Voltage is the item most often skipped

This page is 220–240 V at 50 / 60 Hz. [Wide-range input](https://www.xingguanglightingcn.com/en/glossary#wide-voltage) is not about "works anywhere" — it is about not derating or tripping when the supply sits low or high. In regions with unstable grids, narrow-range drivers fail noticeably more often.

The other thing that gets skipped is inrush: when high-power fixtures start together the inrush adds up and trips the breaker. Where twenty units switch on at once, size the breaker on the row, not on one fixture — undersize it and the symptom is "it trips the moment you switch on", which few people trace back to the lights.

## Voltage drop: right voltage, still dim

Allowed drop on this page is ≤ 3% end to end. It shows up worst on low-voltage and DC systems: a 24 V run of 30 m on 2.5 mm² can lose more than 10% by the far end, the fixtures visibly dimmer and the furthest ones dimmest. On site that looks like a faulty fixture; it is an undersized cable.

On the AC side the working figure is to keep total drop under 3%. That is a wiring parameter, not a fixture parameter — but it decides what the customer sees, so size the cable during the quote, not during commissioning when the lights get blamed.

## Four things to verify before ordering

① Whether flux and [efficacy](https://www.xingguanglightingcn.com/en/glossary#efficacy) are quoted for the complete fixture or the light source — a 10–15% difference that changes the fixture count. ② Whether [colour temperature](https://www.xingguanglightingcn.com/en/glossary#cct) and CRI are measured or nominal values; mixed CCT within one batch is the most common arrival dispute. ③ Driver brand and model, plus its derating curve at high temperature — it is the only part that really sets life. ④ The mounting kit list: chain, bracket and anchors in the box, or the site stops for a day.

## Concepts on this page

[Inrush current](https://www.xingguanglightingcn.com/en/glossary#inrush-current)[High bay](https://www.xingguanglightingcn.com/en/glossary#high-bay)[Ambient temperature rating](https://www.xingguanglightingcn.com/en/glossary#ta-rating)

![LED High Bay HBL-036](https://www.xingguanglightingcn.com/assets/img/prod-hbl036.webp)

### [LED High Bay HBL-036](https://www.xingguanglightingcn.com/en/products/high-bay-light-036)

150W

## Need a Lighting Plan?

Tell us your scenario, Jie Zhai will help you choose.

[Get a Quote](https://wa.me/8613809877696)
[All specification pages](https://www.xingguanglightingcn.com/en/spec/)