Stucke Elektronik SYMAP®F feeder protection
SYMAP® F (Feeder Protection) is a digital multi-functional protection device specially designed by German Stucke Elektronik for feeders, outgoing circuits and distribution networks in the power system.
Unlike the ECG model which focuses on generator control, the core mission of SYMAP® F is to ensure the safety of the power distribution network and to quickly identify and isolate faults in the downstream circuits.
1. Product Description
SYMAP® F is an integrated digital protection relay, mainly used for monitoring and protecting the feeder circuits in medium and low voltage power distribution systems.
It can monitor the current, voltage and frequency of the line in real time. When a short circuit, overload or grounding fault occurs in the line, the device will precisely trigger the circuit breaker to trip. Its design follows the principles of “high reliability and high selectivity”, preventing large-scale power outages due to local faults.
2. Technical Parameter Table
Parameter Item Technical Specification
Power Supply 24V DC or 110V/230V AC (optional configuration)
AC Measurement Input 3-phase current (I1. I2. I3) + 1 neutral current (Io); 3-phase voltage (U1. U2. U3)
Frequency Range 40 Hz – 70 Hz (support 50/60 Hz systems)
Protection Function (ANSI) Overcurrent Protection (50/51), Neutral Overcurrent (50N/51N), Overvoltage/Undervoltage (59/27), Negative Sequence Protection (46)
Measurement Accuracy Current/Voltage: 0.5 class; Power: 1 class
Logic Control Internal programmable logic, supports circuit breaker interlock control
Communication Interface RS485 (Modbus RTU), Profibus DP, or Ethernet (IEC 61850)
Display Interface Backlit graphic LCD, supports real-time vector graph display
Enclosure Protection Front panel IP54. complies with IEC 60529 standard
3. Related Models
The SYMAP® F family includes multiple variants for different grid environments:
SYMAP® F-L: Basic model, focusing on current protection, suitable for simple industrial feeders.
SYMAP® F-V: Voltage-enhanced version, featuring advanced voltage protection and frequency monitoring capabilities.
SYMAP® F-D: Directional Overcurrent Protection (67/67N), suitable for ring network distribution systems.
SYMAP® F-Compact: Compact design, suitable for use in extremely small distribution cabinets.
4. Application Cases
Industrial Distribution Network: Protection of outgoing circuits of distribution boards in large factories such as steel mills and chemical plants.
Ship power distribution system: Responsible for providing secondary protection from the main distribution panel to each distribution branch (such as lighting system, deck machinery, ventilation system).
Commercial buildings: Power distribution monitoring for high-demand locations such as data centers and hospitals.
Substation Automation: As the core protection unit of the medium-voltage switchgear, it communicates with the upper-level SCADA system.

SYMAP®F
5. Product Advantages & Features
Comprehensive fault recording: Built-in disturbance recorder (Disturbance Recorder) and sequence of events recording (SOE), facilitating the investigation of causes after an accident.
Multi-protocol communication capability: Supports the IEC 61850 international standard, enabling easy integration into modern digital substation systems.
Flexible protection curve: Offers a variety of commonly used inverse-time current protection curves (IDMT), and supports user-defined curves.
Modular design: The I/O interface can be expanded according to requirements, significantly enhancing the utilization rate of the hardware.
Sturdy and durable: Successfully passed rigorous tests for earthquake resistance, impact resistance and EMC electromagnetic compatibility, meeting the extreme environmental requirements of marine and heavy industry.
6. Other Models in the Same Series (Other models in the same series)
The SYMAP® series constitutes a complete power distribution protection ecosystem:
SYMAP® G: Generator-specific protection (Generator Protection).
SYMAP® T: Transformer Protection (Transformer Protection), featuring differential protection function.
SYMAP® Y: Motor Protection (Electric Motor Protection), focusing on start-up monitoring and overcurrent protection.
SYMAP® BC: Bus-tie Protection and Control (for managing busbar sectionalizing circuit breakers).