# OEM Control Box DC Wiring Check (Inrush Limiter & DC Breaker)

**URL:** https://forum.universal-robots.com/t/oem-control-box-dc-wiring-check-inrush-limiter-dc-breaker/42068
**Category:** Technical Questions
**Created:** [January 20, 2026, 11:10pm UTC](https://forum.universal-robots.com/t/oem-control-box-dc-wiring-check-inrush-limiter-dc-breaker/42068 "2026-01-20T23:10:58Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![haoyangwang123](https://avatars.discourse-cdn.com/v4/letter/h/bbe5ce/32.png) [@haoyangwang123](https://forum.universal-robots.com/u/haoyangwang123)
#### Post date: [January 20, 2026, 11:10pm UTC](https://forum.universal-robots.com/t/oem-control-box-dc-wiring-check-inrush-limiter-dc-breaker/42068/1 "2026-01-20T23:10:58Z")

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Hi all,

I’m setting up a **UR OEM Control Box** powered by an external **48 V DC PSU** and would like a quick sanity check on the wiring and component selection.

**Planned wiring:**

- 48 V DC PSU → **DC circuit breaker** → **inrush current limiter** → OEM Control Box (+48 V)

- –48 V connected directly back to the PSU

- PE properly bonded between PSU and OEM Control Box  
(see attached diagram)

**Questions:**

1. Does this wiring concept look correct for the OEM Control Box?

2. For the **inrush current limiter** , what cold resistance would you recommend (e.g., 0.5Ω, 1Ω, etc.)?

3. For the **DC circuit breaker** , what trip current rating would you suggest?

Thanks for any advice or practical experience.

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### Author: ![stco](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/stco/32/4363_2.png) [@stco](https://forum.universal-robots.com/u/stco)
#### Post date: [January 26, 2026, 5:00pm UTC](https://forum.universal-robots.com/t/oem-control-box-dc-wiring-check-inrush-limiter-dc-breaker/42068/2 "2026-01-26T17:00:52Z")

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Hello,

See OEM CB Installation Guide and UR - Battery Supply Installation documents linked below for more information.

> **[Universal Robots - OEM Control Box Installation guide - English (en) -...](https://www.universal-robots.com/download/manuals-e-seriesur-series/installation-guides/oem-control-box/oem-control-box-installation-guide-english-en-e-seriesur-series/)**

[Universal Robots - Battery Supply Installation - e-Series](https://www.universal-robots.com/download/manuals-e-seriesur-series/installation-guides/battery-supply-installation-e-series/)