GE Multilin 745-W2-P15-G5-HI-A-L-R-E-H – Transformer Differential Protection Relay | GE Multilin 745 Series
The GE Multilin 745 is a microprocessor-based transformer management relay engineered for comprehensive protection, monitoring, and control of two- and three-winding power transformers in utility and industrial substation environments. The 745-W2-P15-G5-HI-A-L-R-E-H variant is fully configured for high-impedance bus differential applications with advanced communications and enhanced I/O, making it a preferred choice for procurement engineers specifying mission-critical transformer protection schemes.
Product Positioning: Designed as a primary protection device for power transformers rated from distribution to transmission class, the GE 745 replaces legacy electromechanical differential relays while adding integrated metering, event recording, and digital communications — eliminating the need for separate monitoring equipment.
Complete Technical Specifications
- Model / SKU: 745-W2-P15-G5-HI-A-L-R-E-H
- Series / Platform: GE Multilin 745 Transformer Management Relay
- Manufacturer: GE Multilin (General Electric Grid Solutions)
- Protection Functions: Transformer differential (87T), restricted earth fault (REF), overcurrent (50/51), earth fault (50N/51N), overfluxing (24), thermal overload (49), under/overvoltage (27/59), frequency (81), breaker failure (50BF)
- Winding Configuration: W2 — Two-winding transformer protection
- CT Input Rating: P15 — 1A/5A dual-rated current transformer inputs
- I/O Configuration: G5 — Enhanced digital I/O module (16 digital inputs, 8 output relays)
- High-Impedance Option: HI — High-impedance bus differential protection enabled
- Power Supply: A — AC/DC universal power supply (85–265 V AC/DC)
- Communications Port 1: L — RS-485 serial (Modbus RTU / DNP3)
- Communications Port 2: R — RS-232 front panel port
- Enhanced Features: E — Event recorder, oscillography, data logger
- Housing: H — Standard 19-inch rack / panel-mount chassis
- Nominal Frequency: 50/60 Hz selectable
- Operating Temperature: -20°C to +60°C
- Storage Temperature: -40°C to +85°C
- Humidity: 5–95% RH, non-condensing
- Dielectric Withstand: 2 kV AC, 1 minute (IEC 60255-5)
- Impulse Withstand: 5 kV (IEC 60255-5)
- EMC Compliance: IEC 60255-22, IEEE C37.90
- Seismic Qualification: IEEE 344
- Weight: 900 g (approx.)
- Mounting: Panel flush mount / 19″ rack mount
- Country of Origin: Canada / USA (GE Multilin manufacturing)
Proven Application Environments
- Utility transmission and distribution substations (11 kV – 500 kV transformer bays)
- Industrial power systems: petrochemical plants, steel mills, mining operations
- Renewable energy step-up transformer protection (wind farm, solar PV collector substations)
- Data center and critical facility main transformer protection
- High-impedance bus differential schemes in ring-bus and breaker-and-a-half configurations
- Retrofit replacement for GEC Alsthom, ABB, and legacy GE electromechanical differential relays
Engineering Advantages
- Dual-slope differential characteristic with harmonic restraint (2nd and 5th) eliminates false trips during transformer energization inrush
- Integrated REF protection removes the need for a separate restricted earth fault relay panel
- Oscillography and event recording (64 events, 15-cycle waveform capture) accelerates post-fault analysis and reduces outage duration
- Modbus RTU + DNP3 Level 2 dual-protocol support enables seamless integration with both legacy SCADA and modern IEC 61850-ready control systems via protocol converters
- Universal power supply (85–265 V AC/DC) simplifies installation across mixed AC/DC substation battery systems
- Self-monitoring and diagnostics with watchdog relay output ensures relay health is continuously supervised
System Architecture & Signal Flow
The 745 relay receives three-phase current signals from the primary and secondary winding CTs, applies vector group compensation and CT ratio correction in software, and continuously computes the differential and restraint currents. Under normal load, the differential current remains within the operate characteristic. On internal fault detection, the relay issues a trip command to the associated circuit breakers within <1 cycle. The HI option adds a dedicated high-impedance differential element for bus protection, sharing the same chassis and communications infrastructure. All analog inputs are sampled at 64 samples/cycle, processed by a 32-bit DSP, and logged to non-volatile memory for post-event retrieval via the front RS-232 port or rear RS-485 bus.
Sourcing & Quality Verification
- Origin: Genuine GE Multilin OEM product — not aftermarket or remanufactured
- Traceability: Each unit ships with GE factory test report and serial number traceable to GE Multilin production records
- Inspection: Pre-shipment functional verification performed by Konmask technical team including power-on self-test, communications check, and output relay continuity
- Condition: New surplus / refurbished units clearly identified at time of quotation — condition grade disclosed before order confirmation
- Warranty: 12-month Konmask warranty covering defects in materials and workmanship
- Certifications: CE, UL, CSA (per GE Multilin product certification)
Procurement Process
- Step 1 — Inquiry: Submit your RFQ via the product page or email support@konmask.com with quantity and required delivery date
- Step 2 — Quotation: Konmask responds within 1 business day with price, lead time, and stock confirmation
- Step 3 — Order Confirmation: Purchase order accepted via email; proforma invoice issued for payment processing
- Step 4 — Shipment: Units dispatched via DHL / FedEx with full tracking; export documentation (commercial invoice, packing list, COO) provided
- Step 5 — After-Sales: Technical support available for commissioning assistance and relay setting file review
Technical FAQ
Q: Is the 745-W2-P15-G5-HI-A-L-R-E-H compatible with IEC 61850?
A: The base 745 platform uses Modbus RTU and DNP3. IEC 61850 GOOSE/MMS requires the optional Ethernet communications card (suffix “E2” or “EN”). A protocol converter (e.g., SEL-2411) can bridge DNP3 to IEC 61850 if required.
Q: Can this relay protect a three-winding transformer?
A: The W2 suffix designates two-winding configuration. For three-winding transformers, specify the 745-W3 variant. Contact Konmask to confirm availability.
Q: What setting tool is required?
A: GE EnerVista 745 Setup software (free download from GE Grid Solutions). Settings can be uploaded/downloaded via the front RS-232 port or rear RS-485 port.
Q: What is the typical lead time?
A: In-stock units ship within 3–5 business days. Out-of-stock items typically have a 4–8 week lead time depending on GE Multilin production schedule.
Q: Does Konmask provide relay setting files or commissioning support?
A: Yes. Konmask’s engineering team can review customer-provided setting files and offer commissioning guidance. Contact support@konmask.com for details.
© 2026 Konmask.com. All rights reserved.
Original Source: https://Konmask.com
Contact: support@konmask.com | +0086 19859288691
