GWPR220-AF Feeder Arc Flash Protection Relay

Feeder Protection Functions 

(ANSI 50AF) Arc-only Trip Logic

• Tripping is triggered solely when the light intensity captured by arc sensors in feeder compartments exceeds the operating threshold. The total operating time of optical-only criteria is ≤8ms, which is suitable for severe sudden internal arc faults in feeder cables to isolate faulty feeders without delay.

(ANSI 50AF+50) Dual-Criteria Trip Logic (Arc & Overcurrent)

• Standard configuration logic for industrial feeder circuits. Tripping will only be executed when two conditions are satisfied simultaneously: ① Excessive arc flash detected in the monitored feeder area; ② Secondary feeder current exceeds overcurrent setting value.
  It effectively prevents protection maloperation caused by stray light such as inspection flashlights, ambient reflection and cabinet lighting, with total operating time ≤12ms, widely adopted in feeder systems of substations and industrial plants.

(ANSI 50BF) Breaker Failure Protection

• After the device issues a feeder tripping command, if overcurrent signals of the faulty feeder are continuously detected, tripping signals will be output to drive upstream incoming switches according to the set time delay. This addresses breaker failure issues caused by jammed tripping mechanisms or failed shunt trip coils, acting as backup suppression logic for feeder faults.

(ANSI 50AF) Arc Flash Alarm Function

• Only passive alarm contacts are output without tripping operation. It captures weak incipient arcs induced by loose cable terminals and insulation aging, providing early warning of insulation hazards to avoid deterioration into severe internal short-circuit arcs.

(ANSI 50) Overcurrent Alarm Function

• Real-time sampling of three-phase feeder current analog quantities; an alarm is triggered once the current of any single phase exceeds the alarm setting value. It predicts early signs such as long-term feeder overload, single-phase grounding and cable aging to assist operation & maintenance staff in troubleshooting circuit risks in advance.

 Supporting Auxiliary Functions

Fiber Optic Link Supervision

• Compatible with three types of IEC-standard passive optical detection probes: lens-type arc sensors, ST connector lens arc sensors and ST self-verification arc sensors. Equipped with 4 independent fiber-optic arc acquisition channels to realize partitioned monitoring of multiple feeder compartments. The device continuously performs online verification for fiber breakage, probe damage and optical path attenuation, reducing risks of protection maloperation and failure to trip.

Local HMI Parameter Setting

• The front-panel liquid crystal operation unit supports configuration of CT (Current Transformer) ratio, setting of arc flash operating threshold, switching of soft protection enable/disable for each feeder channel, configuration of breaker failure protection delay & current setting values, and system clock calibration. During maintenance of a single feeder, the arc flash interlock digital input can be activated to inhibit the protection function of the corresponding circuit independently without affecting normal operation of other feeders.

Standardized Fault Event Recorder

• Classified storage of tripping events, arc flash alarm events and digital input status change events. It completely records fault occurrence time, faulty feeder channel number and instantaneous fault current value, complying with IEC specifications for traceability analysis of relay protection faults.

Standardized Passive Relay Output Interface

• Equipped with 2 independent feeder tripping output contacts, protection pickup/operation indication contacts and general alarm signal contacts, all passive dry contacts rated AC250V/5A. It can directly drive feeder circuit breaker tripping, audible & visual alarm devices and power monitoring background systems. Reserved interfaces include DC24V auxiliary power output, equipment expansion digital input channels and RS-485 Modbus-RTU communication interface.

RS-485 Modbus-RTU Serial Communication

• Compliant with IEC 60870 general communication specifications for power distribution equipment. It supports remote reading of real-time feeder current, operating status of arc sensors and retrieval of historical fault reports; communication address and RS-485 baud rate can be modified online to adapt to integrated automation monitoring background systems of power distribution rooms.

Output Relay Manual Test Function

• Independent output verification function. Before factory delivery and on-site commissioning, manual control of make/break of all relay contacts is available to quickly verify the wiring correctness of feeder secondary control circuits.

Application Scenarios

• (1) Feeder Circuits of Power Substations: 10kV/33kV medium-voltage switchgear outgoing feeders, station auxiliary transformer feeders, shunt capacitor bank feeders, voltage transformer feeders, incoming & outgoing feeders of box-type substations.
• (2) Power Distribution Feeders of Industrial Plants: MCC motor feeders in metallurgical, chemical, mining and heavy manufacturing workshops, low-voltage power outgoing cabinets, cable feeder circuits, outgoing cabinets matched with high-power frequency converters.
• (3) Feeder Circuits of New Energy Power Stations: Photovoltaic array combiner outgoing feeders, low-voltage feeders of wind turbine box transformers, high & low-voltage outgoing cable feeders of energy storage cabins.
• (4) Power Distribution Feeders of Public Buildings: Low-voltage power outgoing lines and cable feeders in power distribution rooms of commercial complexes, Grade A tertiary hospitals, universities, stadiums and high-rise office buildings.
• (5) Feeder Circuits of Special Industries: High & low-voltage outgoing feeders of large data centers, motor power distribution feeders of water conservancy pump stations, outgoing circuits of complete switchgears for port & transportation hubs.

Supplementary Professional Comparison: Feeder-type vs Busbar-type Internal Arc-fault Control Device (IACD)

• GWPR350-AF Busbar Arc Flash Protection Relay: Centralized IACD. It trips the main incoming switch upon fault occurrence to isolate the entire busbar section, resulting in a large power outage scope.
• GWPR220-AF Feeder Arc Flash Protection Relay: Distributed feeder-dedicated IACD. It only disconnects the single faulty feeder when a fault occurs to realize Selective Tripping, minimizing the power outage scope and complying with international design criteria for selective power distribution protection.