Real-time optical arc flash detection for MV & HV switchgear, substations and industrial power installations — millisecond-speed arc fault identification, integrated overcurrent supervision, and SCADA-connected alarm management. Stop arc flash damage before it destroys equipment and endangers personnel.
An arc flash is an electrical explosion triggered by a fault current flowing through an unintended arc path in air between energized conductors or between a conductor and ground. The resulting plasma channel reaches temperatures of up to 20,000°C — hotter than the surface of the sun — and releases enormous quantities of radiant heat, pressure wave energy, and molten metal in fractions of a second.
Inside medium-voltage and high-voltage switchgear, an arc flash event can destroy an entire switchroom in milliseconds, cause fatal burns to personnel within several meters, and knock out critical power infrastructure for days or weeks. The severity of an arc flash incident is directly proportional to the arc duration — which is why arc flash detection systems that clear faults in under 100 milliseconds are so dramatically more effective than conventional overcurrent protection alone.
Arc flash events do not announce themselves. They develop from insulation degradation, contamination, or operational errors — and when they occur, the window for protection is measured in milliseconds, not seconds.
Standard time-overcurrent relays are designed to coordinate with upstream protection — meaning they deliberately delay tripping for hundreds of milliseconds to seconds. During that delay, an arc fault releases enormous incident energy. Optical arc flash detection bypasses coordination delays entirely, clearing the fault in under 100 ms total — before catastrophic damage occurs.
IEEE 1584 calculations show that at typical MV switchgear fault levels, even 200 ms of arc duration can produce incident energies exceeding 40 cal/cm² — well beyond the threshold for fatal thermal injuries. Optical arc flash detection reducing arc duration to under 100 ms can bring incident energy below 4 cal/cm² — a manageable hazard category with appropriate PPE.
A single undetected arc flash in MV switchgear can destroy an entire switchroom, requiring complete equipment replacement at costs of hundreds of thousands to millions of dollars — plus extended outage periods causing lost production and regulatory penalties. Arc flash detection systems pay back their cost many times over with the first prevented arc flash incident.
NFPA 70E, IEC 62271-200, and national electrical safety regulations increasingly mandate arc flash risk assessment and active mitigation for MV switchgear. Optical arc flash detection systems directly satisfy these requirements, reduce insurance premiums, and demonstrate due diligence — while protecting the facility against liability following an arc flash incident.
INNO's arc flash detection and monitoring system combines high-speed optical arc sensing with overcurrent supervision logic in a single intelligent relay platform. Point-type optical sensors and optical fiber loop sensors provide complete coverage of all switchgear compartments — busbar sections, cable chambers, and circuit breaker bays — with simultaneous temperature monitoring integration for comprehensive switchgear health surveillance.
| Arc Detection Response Time | < 1 millisecond (light detection to trip signal) |
| Total Fault Clearing Time | < 100 ms (arc detection + CB tripping) |
| Sensor Types | Point optical sensor / Fiber loop sensor (area coverage) |
| Optical Detection Wavelength | Full visible spectrum + near-infrared |
| Overcurrent Supervision | Built-in — prevents false tripping from ambient light |
| Trip Output | Dual-channel relay output — configurable per zone |
| Sensor Inputs per Unit | Up to 8 point sensors or 4 fiber loop zones |
| Communication Protocols | Modbus RTU · RS485 · IEC 61850 GOOSE (optional) |
| Arc Event Logging | Time-stamped arc event records with sensor zone identification |
| Integrated Temperature Monitoring | Optional — fluorescent fiber optic, ±0.5°C accuracy |
| Power Supply | AC/DC wide-range input with battery backup |
| Protection Rating | IP66 (sensors) / IP40 (relay unit) |
| Operating Temperature | -40°C to +70°C |
| Certifications | CE · RoHS · ISO 9001 · ISO 14001 · ISO 45001 |
Dual-channel optical detection combined with overcurrent supervision provides reliable, false-trip-free arc flash protection. The system architecture supports zone-selective interlocking for substations with multiple switchgear sections.
Optical sensors detect the intense light flash of an arc event in under 1 millisecond — far faster than current-based protection. This extreme speed is the critical factor that limits arc flash incident energy to safe levels.
A trip output is only generated when both the optical arc signal AND an overcurrent threshold are simultaneously exceeded — eliminating false trips from photographic flashes, inspection torches, or maintenance activities without any reduction in protection speed.
Each sensor input is assigned to a protection zone — enabling selective tripping of only the affected switchgear section while keeping healthy sections energized. Minimizes outage extent while providing full arc flash protection coverage.
Modbus RTU and IEC 61850 GOOSE communication delivers real-time arc event alarms, sensor zone identification, and time-stamped fault logs to any SCADA or substation automation platform — enabling rapid incident response and post-event root cause analysis.
Understanding how optical arc flash detection compares to existing protection schemes is essential for arc flash risk assessment and mitigation planning under NFPA 70E and IEEE 1584.
| Protection Attribute | Time-Overcurrent Relay | Bus Differential Protection | Zone-Selective Interlock | INNO Optical Arc Flash Detection |
|---|---|---|---|---|
| Fault Clearing Speed | 0.3 – 2.0 seconds | 30 – 100 ms | 50 – 200 ms | ✓ < 100 ms total |
| Arc Incident Energy Reduction | ✗ Minimal | ⚠ Partial | ⚠ Partial | ✓ Up to 90%+ |
| False Trip Immunity | ✓ High | ✓ High | ✓ High | ✓ High (dual supervision) |
| Zone-Selective Operation | ⚠ Limited | ✓ Yes | ✓ Yes | ✓ Yes — by sensor zone |
| Installation Complexity | Low | High — CT matching required | Medium | ✓ Low — optical sensors only |
| SCADA / IEC 61850 Integration | ⚠ Varies | ⚠ Varies | ⚠ Varies | ✓ Modbus RTU / IEC 61850 |
| Temperature Monitoring Integration | ✗ No | ✗ No | ✗ No | ✓ Optional — ±0.5°C fiber optic |
| Retrofit to Existing Switchgear | ✓ Yes | ✗ Difficult | ⚠ Partial | ✓ Yes — sensor clips inside panel |
From industrial MV switchgear in Europe to data center primary distribution in Asia Pacific — INNO arc flash detection systems deliver millisecond-speed protection across the most demanding power applications.
A major automotive manufacturing facility in the West Midlands required arc flash incident energy reduction at its 11 kV primary switchgear serving robot assembly lines, stamping presses and paint shop utilities. An IEEE 1584 arc flash study had identified incident energies exceeding 80 cal/cm² at main busbar level — far beyond the capability of any available PPE and representing an unacceptable personnel risk for maintenance and operational staff.
INNO optical arc flash detection units were installed across all main and distribution switchgear bays, with fiber loop sensors providing complete busbar compartment coverage and point sensors at each cable termination chamber. Overcurrent supervision was wired from existing CTs. The system communicated via Modbus RTU to the facility's Siemens SCADA. Following installation and arc flash re-study, busbar incident energy was reduced to below 6 cal/cm² — enabling maintenance activities under standard PPE Category 2. The facility has reported zero arc flash incidents in 36 months since commissioning.
A hyperscale data center operator in the Seoul metropolitan area required arc flash protection upgrades for its 22 kV medium-voltage switchgear serving 80 MW of critical IT load across a multi-building campus. The operator's risk management framework mandated arc flash incident energy below 8 cal/cm² at all switchgear panels accessible by electrical maintenance personnel — a requirement that existing protection coordination could not satisfy without severely compromising selectivity.
INNO's arc flash detection system with integrated fiber optic temperature monitoring was deployed across all main switch rooms and distribution substations. Zone-selective optical tripping maintained maximum selectivity — clearing only the faulted section while all healthy switchgear remained energized. The IEC 61850 GOOSE interface delivered arc event data directly to the operator's centralized DCIM platform. Temperature correlation identified one switchgear bay with developing hotspot conditions during the commissioning period — allowing pre-emptive maintenance before any fault development.
A major refinery in Abu Dhabi required a comprehensive arc flash mitigation programme for its medium-voltage motor control and distribution switchgear following an arc flash incident during routine maintenance that resulted in severe equipment damage and personnel injuries. Regulatory authorities required the facility to implement active arc energy limitation measures across all MV switchgear bays as a condition of continued operation.
INNO optical arc flash detection units with dual-channel trip outputs were installed across 64 switchgear bays in nine electrical substations. Point sensors covered cable chambers and bus sections; fiber loop sensors provided busbar compartment coverage. Integration with the plant's ABB System 800xA DCS via Modbus RTU delivered arc event notifications directly to the central control room. The complete installation was executed in 11 days during a planned turnaround — with zero interference to the facility's operating processes. Post-installation arc flash study confirmed incident energy reduction at all panels to below the facility's 8 cal/cm² target.
Contact our application engineers — they'll analyze your switchgear type, bay count, existing protection coordination and fault level to design the right arc flash detection system for your specific requirements.
INNO arc flash detection systems are engineered for every critical switchgear environment — from primary distribution substations and industrial MV networks to data centers, generator switchboards and ring main units. One monitoring platform covering your entire high-voltage infrastructure.
Optical arc flash detection for 6 kV, 10 kV, 35 kV and higher voltage air-insulated and gas-insulated primary distribution switchgear. Fiber loop sensors provide area coverage of complete busbar sections; point sensors target cable chambers and breaker compartments. Full retrofit capability — no panel outage required for sensor installation.
Switchgear Monitoring Solutions →
Arc flash in motor control centers is one of the most common causes of electrical injuries in industrial facilities — driven by high-density wiring, frequent maintenance access, and limited busbar clearances. INNO point sensors in each MCC compartment provide targeted arc detection at the highest-risk locations, with zone-selective tripping that minimizes motor outage scope when a fault occurs.
Inquire About MCC Arc Flash Detection →
Uptime Institute Tier certification, insurance requirements, and internal risk frameworks increasingly mandate active arc flash mitigation for data center primary and secondary MV switchgear. INNO arc flash detection with IEC 61850 GOOSE integration delivers the speed and audit trail that data center operators need — with minimal installation disruption to energized systems.
Data Center Arc Flash Inquiry →
Generator output switchboards and unit auxiliary switchboards in power plants operate at high fault levels — making arc flash incident energies extremely high without active mitigation. INNO arc flash detection on generator switchboards provides millisecond-speed protection that works in harmony with generator protection schemes, enabling rapid fault isolation without interfering with synchronization or load shedding logic.
Power Plant Arc Flash Inquiry →
Urban distribution ring main units present elevated arc flash risk — compact enclosures, cable plug terminations under constant thermal cycling, and frequent maintenance access in confined spaces. INNO's miniaturized arc flash sensor package installs within RMU cable chambers without outage, providing continuous optical arc detection with wireless alarm communication to remote monitoring platforms.
Send RMU Arc Flash Inquiry →
Gas-insulated and air-insulated transmission substations require arc flash protection at bus sections, disconnect switches, and cable sealing ends where maintenance access occurs. INNO's arc flash detection system complements existing differential and distance protection schemes — providing a final layer of ultra-fast arc energy limitation that no conventional relay scheme can match.
SF6 & GIS Monitoring Solutions →Arc flash detection is most effective when combined with comprehensive thermal monitoring across all critical power assets. INNO offers a complete range of fiber optic temperature monitoring systems — from switchgear busbars to transformer windings, motor windings, and cable joints.
Complete fluorescent fiber optic temperature measurement system for MV and HV switchgear — covering busbars, cable terminations, and circuit breaker contacts. 25-year calibration-free sensors, ±0.5°C accuracy, Modbus RTU / IEC 61850 integration.
View Product →Miniaturized fiber optic temperature sensor system for cable plug joints inside compact ring main unit enclosures. Non-intrusive installation, IP66 rated, supports wireless LoRa communication for urban distribution substation deployment.
View Product →Continuous winding and bearing temperature monitoring for standby and prime power generator sets. Fully immune to the strong electromagnetic fields and vibration environment of generator enclosures — providing reliable thermal protection that conventional sensors cannot achieve.
View Product →Fiber optic temperature measurement device for air-core and dry-type reactors in substations and industrial installations. Embedded sensor probes measure hot-spot temperatures directly within reactor windings — providing continuous overtemperature protection and load management.
View Product →Armored fluorescent fiber optic temperature probes designed for direct immersion in transformer oil — measuring winding hot-spot temperature at the actual hot-spot location per IEC 60076-7 requirements. Rated for continuous operation in high-voltage transformer environments up to 140 kV withstand.
View Product →Clip-on and adhesive-mount fluorescent fiber optic sensors for continuous temperature measurement at busbar joints, bolt connections, and cable terminations. Calibration-free for 25+ years — the definitive solution for hotspot detection at the most common failure initiation points in switchgear.
View Product →Fluorescent fiber optic sensors embedded directly in motor stator windings provide accurate, continuous hot-spot temperature measurement — immune to motor electromagnetic interference that defeats all conventional NTC/PTC and RTD sensors. Enables tighter overtemperature protection and longer motor service life.
View Product →Complete multi-channel fiber optic temperature monitoring system for oil-immersed power transformers — covering winding hot spots, top oil, and bushing connections. Real-time thermal health index, load management, and IEC 61850 SCADA integration from a single compact transmitter unit.
View Product →INNO fiber optic and sensing systems cover every critical monitoring dimension of modern switchgear — from arc flash detection and thermal hotspots to partial discharge and gas leakage. One platform. One manufacturer. Complete protection.
Real-time monitoring of circuit breaker contact temperature, mechanical wear and thermal anomalies. Early fault warning reduces arc flash risk and extends equipment service life.
Learn More →Precisely detect thermal hotspots at busbar joints, cable terminations and contact points before faults develop. Enable proactive preventive maintenance and eliminate unplanned outages caused by thermal defects.
Learn More →Continuously track busbar temperature distribution and insulation degradation trends. Ensure reliable power transmission across main and sectional busbars with IEC 61850 / Modbus RTU SCADA integration.
Learn More →Real-time optical arc flash detection and precise fault zone location for millisecond-speed protective response. Effectively prevent arc flash incidents from causing severe damage to equipment and personnel.
You Are Here →Comprehensive temperature measurement across all critical switchgear assets for early detection of overheating and proactive maintenance. Fiber optic sensors rated to 140 kV — fully suited for high-voltage environments.
Learn More →Real-time tracking of SF6 gas leakage and concentration in gas-insulated switchgear. Ensure safe GIS operation and environmental compliance while reducing the risk of insulation failure.
Learn More →Continuous acquisition and analysis of partial discharge activity. Early identification of insulation defects through high-sensitivity UHF, TEV and ultrasonic sensors to reduce unplanned switchgear failures.
Learn More →A unified platform integrating temperature, arc flash, partial discharge, SF6 gas and mechanical condition monitoring into one dashboard. Multi-bay, multi-device visibility from a single system with full SCADA / IEC 61850 integration.
Explore Full Platform →Founded in 2011 in Fuzhou, China, INNO Instrument — Fuzhou Innovation Electronic Science & Technology Co., Ltd. — is a vertically integrated manufacturer of fluorescent fiber optic temperature sensors, arc flash detection systems, partial discharge monitoring platforms, and integrated online monitoring solutions for power infrastructure worldwide.
With over 15 years of R&D investment and in-house production of optical sensors, detection relay electronics, and monitoring software, INNO supports global switchgear OEMs, EPC contractors, power utilities, and system integrators with fully customized arc flash protection solutions. Our engineering team works directly with your design and procurement teams to deliver factory-calibrated, application-specific systems — ready to embed in your equipment from day one, with full OEM documentation, traceability records, and co-branding options.
Bespoke optical sensor geometries, fiber routing schemes, and relay architectures for factory embedding in switchgear panels — designed to your dimensional and protection coordination requirements.
Combined optical arc flash detection and fluorescent fiber optic temperature sensing in a single integrated platform — co-developed with your switchgear design for seamless OEM integration.
Co-branded arc flash monitoring dashboards and alarm management interfaces configured to your brand identity, protocol stack, and customer-facing reporting requirements.
Dedicated application engineering, FAT/SAT support, IQ/OQ qualification documentation, and ongoing post-deployment technical assistance for regulated and safety-critical installations.
End-to-end in-house production — from optical sensor fabrication through relay electronics assembly, software development and final system integration — gives INNO the flexibility and traceability that global OEM partners require.
From utility substations to hyperscale data centers — electrical professionals worldwide rely on INNO arc flash detection to protect their most critical switchgear assets and personnel.
We deployed INNO's optical arc flash detection system across our primary MV switchgear following an IEEE 1584 arc flash study that identified unacceptable incident energy levels. The installation was straightforward — fiber loop sensors routed inside existing cable compartments without any panel outage. Post-installation re-study confirmed incident energy below 8 cal/cm² at all panels. The Modbus RTU integration with our Siemens SCADA was seamless. The system is now standard specification on all our new switchgear procurement.
The combined arc flash detection and temperature monitoring capability is what differentiated INNO from competing solutions we evaluated. At our 22 kV data center primary switchgear, we now have real-time arc protection with simultaneous thermal condition monitoring at every bay. The IEC 61850 GOOSE integration delivered arc event notifications directly to our DCIM platform within one day of commissioning. The engineering support from INNO was excellent throughout the project.
After an arc flash incident at one of our refineries, we implemented INNO arc flash detection systems across all 64 switchgear bays in our facility during a planned turnaround. The speed of installation was impressive — the INNO team completed commissioning in under two weeks. The dual-channel trip logic with overcurrent supervision gave our protection engineers the confidence they needed — no false trips, no nuisance outages. The arc flash risk assessment results after installation showed compliance across all panels.
INNO provided OEM-integrated arc flash detection modules for switchgear panels we supply to major utility and industrial clients across Southeast Asia. The factory calibration quality, CE certification, and complete documentation package met all our clients' procurement requirements without exception. The arc flash relay hardware is compact, reliable, and easily configured for each application. INNO is now our standard OEM partner for integrated arc flash protection on all new switchgear deliveries.
INNO's quality management system, products, and environmental practices are independently audited and certified to the highest international standards — providing procurement teams and project engineers the documentation required for critical power infrastructure applications worldwide.
Quality Management System — certified manufacturing and product quality control ensuring consistent, traceable production at every stage.
Environmental Management System — verified responsible environmental practices across all manufacturing and operational processes.
Occupational Health & Safety Management — certified safe workplace practices protecting employees and contractors at all INNO facilities.
Information Security Management — certified data and intellectual property protection standards covering all OEM project and customer data.
European Conformity — all products comply with EU safety, health, and environmental protection requirements for sale and deployment across the European Union and EEA.
Restriction of Hazardous Substances — all products meet EU RoHS Directive requirements for restricted materials, supporting customer environmental compliance programs.
All arc flash detection sensors and relay units are calibrated and tested in INNO's internal metrology laboratory against traceable reference standards before shipment. Every unit ships with a test certificate and full measurement traceability record.
Complete installation qualification (IQ) and operational qualification (OQ) documentation packages are available for regulated industry applications — supporting pharmaceutical, nuclear, food processing, and GxP-compliant facility deployments.
INNO arc flash detection relay units have been independently verified for Modbus RTU interoperability and IEC 61850 GOOSE compliance against Siemens, ABB, Schneider and GE relay and SCADA platform families — ensuring reliable integration in any substation environment.
Optical sensor cables and fiber loop sensors are tested to high-voltage withstand requirements per IEC 60243 prior to shipping. Test certificates included with each delivery — providing the documentation required for MV switchgear qualification packages.
Have a question about arc flash detection for your specific application?
Our application engineers respond within 4 hours. Share your switchgear type, voltage level and bay count — we'll recommend the right arc flash detection configuration at no charge.
Share your switchgear type, voltage level and panel layout — receive a custom arc flash detection system configuration, bill of materials and quotation within one business day. Completely free, no commitment required.
Disclaimer: The technical specifications, case data and performance figures presented on this page are for reference only. Actual results may vary depending on installation environment, equipment condition and operating parameters. INNO reserves the right to update or modify product specifications without prior notice. Please contact us through official channels for formal quotations or technical confirmation.
