Description
Overview of Arc flash protection relay
- Arc flash protection relay, the ATN-800H arc protection device is a multifunctional unit widely applied in power, water conservancy, transportation, industrial, mining, new energy, marine and railway fields.
- It delivers arc flash protection and automatic control for power transmission and distribution systems, and adapts to operating modes including single busbar and sectional double busbar.
- Equipped with arc sensors offering over 180° blind-free horizontal coverage, the device boasts high sensitivity and excellent anti-electromagnetic interference performance.
Product Features
- Supports arc alarm, arc tripping, zero current alarm, zero voltage alarm, MT interlock and delayed circuit breaker failure protection.
- Equipped with comprehensive self-check function.
- Relay outlet response time<3ms, arc tripping time<8ms.
- Built-in RS485 and Ethernet ports, compatible with Modbus protocol.
- Arc blocking function available via external switches and maintenance pressing plates.
- Event logging function records trips, alarms and remote signal changes in real time.
- Compatible with various arc sensors, adjustable arc action threshold.
- Multilingual switching available, supporting Chinese, English and Russian.
Block Diagram of the Arc Flash Protection Function

Device Parameters
| Item | Specification |
|---|---|
| Working Power | AC/DC 85-265V |
| Rated Current Input | 5A/1A, 50Hz/60Hz |
| Measuring Range | 0.06-10In |
| Error | ±2.5% |
| Number of ARC Channels | 24/36/48 channels optional |
| Sensor Type | Visible Light, Ultraviolet Light |
| Transmission Medium | Plastic Optical Fiber |
| Visible Optical Threshold | 8000lux(±20%) |
| UV Threshold | 5mw/cm²(±20%) |
| UV Spectrum Bandwidth | 280nm~400nm |
| ARC Trip Time | ≤8ms |
| ARC & Current Trip Time | ≤15ms |
| MT Trip Time | ≤15ms |
| Circuit Breaker Failure Delay Time | 100-300ms |
| Relay Output Quantity | 12 Trip Output |
| Communication Interface | 2RS485, 3ETH optional |
| Baud Rate | 4800/9600(Default)/19200 |
| Communication Protocol | Modbus RTU / Modbus TCP |
| Working Temperature | -10℃~+55℃ |
| Storage Condition | -25℃~+70℃, 5-95%RH |
FAQ
Q1: What is an Arc Protection Device?
It is a standalone electrical protection hardware that detects arc flash faults via optical sensors and current detection modules. It acts as the core sensing and execution unit of arc fault protection, supporting fast fault judgment and trip signal output for power system safety protection.
Q2: What is the difference between Arc Fault Protection System and a single arc protection device?
The arc fault protection system is a complete integrated solution composed of arc protection relays, optical fiber sensors, trip circuits and auxiliary modules. A single arc protection device is only a part of the system. The whole system realizes systematic monitoring, judgment and rapid fault elimination.
Q3: What is Medium Voltage Arc Flash Protection used for?
It is a dedicated protection technology for medium-voltage power systems (3kV–35kV). Medium-voltage arc flash releases huge thermal and mechanical energy, which easily damages switchgear and endangers personnel. This protection mode adopts high-speed detection and tripping (within milliseconds) to minimize equipment damage and safety risks.
Q4: What is a Busbar Arc Protection Relay?
It is a special relay for busbar arc fault protection. Targeting frequent arc flash risks in power distribution busbars, it matches high-sensitivity optical detection and overcurrent criterion. It can accurately locate busbar internal faults and quickly cut off power supply to avoid large-scale power outage accidents.
Q5: What is Switchgear Arc Flash Protection?
It is targeted protection for internal arc faults of high and medium voltage switchgear cabinets. It deploys distributed optical sensors inside switchgear compartments, monitors arc flash in real time, and cooperates with breakers to trip rapidly. It effectively protects switchgear equipment and on-site maintenance personnel.
Q6: What is the core working principle of these arc protection products?
All mainstream arc protection solutions adoptlight + current dual criteria. The system detects the strong light signal generated by arc flash instantly and verifies with abnormal overcurrent. It avoids false tripping and realizes reliable millisecond-level fault isolation.
Q7: Why is arc flash protection essential for medium voltage switchgear and busbars?
Medium voltage equipment features high voltage and large current. Once an arc fault occurs, it will produce instantaneous high temperature and impact pressure, causing equipment burnout, cabinet explosion and personal injury. Arc flash protection is the most effective means to mitigate medium voltage arc fault hazards.











xiao zhang –
This arc flash protection device delivers ultra-fast tripping to restrain short-circuit damage caused by internal cabinet arc faults, equipped with superior anti-interference performance for safe operation of medium-voltage switchgear in substations.
Jack –
Works reliably in substations — a dependable product.