# Can optical fibers be used on high-voltage power lines?

**URL:** <https://forum.ofscn.net/t/can-optical-fibers-be-used-on-high-voltage-power-lines/3135>\
**Category:** OFSCN Technical Knowledge Base\
**Tags:** fbg-technology\
**Created:** [October 23, 2026, 5:07am UTC](https://forum.ofscn.net/t/can-optical-fibers-be-used-on-high-voltage-power-lines/3135 "2026-10-23T05:07:30Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![VoidWalker](https://forum.ofscn.net/letter_avatar_proxy/v4/letter/v/848f3c/32.png) [@VoidWalker](https://forum.ofscn.net/u/VoidWalker)\
**Post date:** [October 23, 2026, 5:07am UTC](https://forum.ofscn.net/t/can-optical-fibers-be-used-on-high-voltage-power-lines/3135/1 "2026-10-23T05:07:30Z")

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Can hundreds of thousands of volts of high voltage break down optical fibers? Does the metal casing need to be grounded?

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**Author:** ![OFSCN\_Tech\_Expert](https://forum.ofscn.net/user_avatar/forum.ofscn.net/ofscn_tech_expert/32/199_2.png) [@OFSCN\_Tech\_Expert](https://forum.ofscn.net/u/OFSCN_Tech_Expert)\
**Post date:** [October 23, 2026, 5:08am UTC](https://forum.ofscn.net/t/can-optical-fibers-be-used-on-high-voltage-power-lines/3135/2 "2026-10-23T05:08:19Z")

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In high-voltage transmission lines, substations, and UHV power engineering, fiber optic sensing technologies (such as Fiber Bragg Grating FBG, Distributed Optical Fiber Sensing, etc.) have been widely applied. The technical principles for the insulation characteristics of optical fibers in a tens of thousands of volts high-voltage environment and the potential treatment of metal encapsulation are analyzed as follows:

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### I. Will tens of thousands of volts high voltage break down optical fibers?

**Conclusion: The optical fiber material itself will not be penetrated and broken down by the electric field directly, but “surface discharge (flashover) burnout” must be strictly prevented in engineering.**

1. **Material Physical Insulation Strength (Bulk Breakdown)**:

2. **Main Failure Mechanism: Surface Discharge and High-Temperature Arc Melting (Flashover)**:

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### II. Does metal encapsulation need to be grounded?

**Conclusion: Metal encapsulation sensors installed on high-voltage power lines are strictly prohibited from being grounded and must be installed with “equipotential installation”; continuous metal casings are strictly prohibited in areas spanning potential differences.**

1. **High-Voltage Conductor Side: Equipotential Installation (Strictly Prohibited Grounding)**:

2. **Principle of Potential Transfer Isolation** :

3. **Specifications for Metal Components on the Low-Voltage/Ground Potential Side** :

* * *

### III. Selection of Sensing Encapsulation in High-Voltage Strong Electric Field Environment

To completely eliminate local electric field distortion, suspended potential discharge, or induced eddy current heating caused by metal casings in high-strength alternating electric fields, **ceramic encapsulation** or **all-dielectric polymer encapsulation** is usually preferred for direct temperature and strain measurement on primary high-voltage power equipment:

#### 1. Ceramic Insulated Encapsulated Sensor

Encapsulates fiber Bragg gratings using high-insulation ceramic materials. It has no metal components and naturally possesses high-voltage resistance, high-temperature resistance, and high insulation impedance characteristics.

- [OFSCN Ceramic-encapsulated Fiber Bragg Grating Temperature Sensor](https://www.ofscn.net/fbg-products/fbgs-insulated.html)

 ![OFSCN Ceramic-encapsulated Fiber Bragg Grating Temperature Sensor](https://forum.ofscn.net/uploads/default/original/1X/f09006a45da58a909a27f5408ac16ee45a64c15a.jpeg)  
 ![OFSCN Ceramic-encapsulated Fiber Bragg Grating Temperature Sensor](https://forum.ofscn.net/uploads/default/original/1X/3e37c7c250a893bbc335a2c3625f3ea586cd3091.jpeg)

#### 2. Polymer Encapsulated Sensor

Encapsulates the grating section with non-metallic polymer materials, combining flexibility and insulation properties to avoid metal electric field concentration effects.

- [OFSCN® Polymer-encapsulated Fiber Bragg Grating Strain Sensor (0.7mm/1.2mm diameter)](https://www.ofscn.net/fbg-products/strain-sensor-4.html)

 ![OFSCN® Polymer-encapsulated Fiber Bragg Grating Strain Sensor](https://forum.ofscn.net/uploads/default/original/1X/c612094d0ef82975277313d0e558f56fa6054f6e.jpeg)  
 ![OFSCN® Polymer-encapsulated Fiber Bragg Grating Strain Sensor](https://forum.ofscn.net/uploads/default/original/1X/6569d200237be13024927a10fcc46127e853018d.jpeg)