CEI 0-16 Protection Relays
SEB SIGMA-L PLUS protection relays for Medium and Low Voltage grid compliance: DIA4L+ (Interface) and IFD4L+ / IFX4L+ (General Protection).
Presentation of the complete SEB protection relay line: Interface Protections (PI), General Protections (PG), and MV/LV line protections.
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Available Models
DIA4L+
PIFor MV-Connected Auto-Producers
Provides 3-phase under/overvoltage, residual overvoltage, under/overfrequency, and voltage unblocking functions. Complies functionally with CEI 0-16 requirements for interface protection (PI).
- SigmaOR Function: OR logic for coordinating multiple interface protections (up to 8 SPI) with connection integrity monitoring
- Automatic reclosing function with configurable waiting time and maximum operations
- Connection schemes with 2 MV VTs or direct in LV
IFD4L+
PGPhase, Earth, and Directional Earth Overcurrent
Multi-function digital relay for Medium Voltage feeder overcurrent and directional earth fault protection. Complies functionally with CEI 0-16 for general protection (PG).
- 3 phase overcurrent thresholds, 3 earth thresholds, 3 directional earth thresholds, and 2 residual overvoltage thresholds
- Definite time or inverse time tripping according to IEC 60255-151
- Hardwired and virtual logic selectivity (UDP SigmaSlim protocol); 2 setting banks
IFX4L+
PGPhase and Earth Overcurrent Protection
Medium Voltage feeder and earth fault protection relay with 95% stator earth fault and transformer tank protection. Complies functionally with CEI 0-16 for general protection (PG).
- 3 phase overcurrent thresholds and 3 earth thresholds, definite or inverse time (IEC 60255-151)
- 95% stator earth fault protection (64S) and transformer tank protection (64T)
- Hardwired and virtual logic selectivity; seamless compatibility with IFD4L+
Range Capabilities
Shared capabilities, configurable from the front panel keypad or via SigmaPRO software.
8 Programmable LEDs
Visual indication of trip thresholds with latched memory, also reported on the LCD display.
6 Output Relays
4 command relays (SPDT, 8 A) and 2 signaling relays (SPST, 7 A), assignable to individual thresholds.
7 Digital Inputs
Optoisolated: breaker status/command, external trip, threshold inhibition, setting bank selection.
50 Events + Datalogger
Fault event recording with measured electrical values and 200-event disturbance log.
2 Setting Banks
Selectable via keypad, configuration software, or digital input for active/passive modes.
Continuous Self-Diagnostics
Microprocessor watchdog monitoring with anomaly indication via dedicated LED and fail-safe relay.
Animated Mimic Display
On-screen display showing up to 3 switchgear devices with real-time electrical measurements.
Modbus Communication
Front USB Type-C, RS485 Modbus RTU, and Ethernet Modbus TCP/IP for SCADA and RTU integration.
SigmaPRO & SigmaPLC
Complimentary SigmaPRO setup software; text-based programmable logic and virtual logic selectivity.
Technical Specifications
Standard parameters common to the SIGMA-L PLUS models.
Regulatory Standards
CEI 0-16 — DIA4L+ (Interface Protection), IFD4L+ / IFX4L+ (General Protection)
Auxiliary Power Supply
LV: 24÷80 Vac / 24÷90 Vdc ±20% · HV: 80÷230 Vac / 90÷250 Vdc ±20%
Frequency (Vac)
47÷63 Hz
Power Consumption (min/max)
3.5 W / 6.5 W – 5 VA / 17 VA
Voltage Inputs (DIA4L+)
50÷400 V configurable (Un), zero-sequence 50÷400 V (Uon)
Current Inputs (IFD4L+, IFX4L+)
1 A or 5 A configurable (In, Ion)
Digital Inputs
7 optoisolated, 2 mA
Output Relays
4 trip control (SPDT, 8 A) + 2 signaling (SPST, 7 A), 250 V
Communication Ports
Front USB Type-C · RS485 Modbus RTU (1200–57600 baud) · Ethernet 100BaseTX Modbus TCP/IP
Configuration
Front keypad with LCD or free SigmaPRO software
Advanced Features
SigmaPLC (text-based logic), virtual logic selectivity, SigmaOR (DIA4L+ only)
Operating Temperature
-25 to +70 °C
Storage & Transport
-40 to +85 °C, relative humidity < 93% non-condensing
Front Protection
IP 52 (flush-mounted)
Weight
1.4 kg
Mounting
Flush panel / 19" rack mount (up to 4 devices)
Need Assistance Selecting the Right Protection Relay?
Our engineering team supports you in configuring the optimal protection system tailored to your plant, fully compliant with CEI 0-16.