Product Core Brief
- Model: , Main OEM Part Code: HESG324426R1 / HESG324426M1
- Brand: ABB Hitachi Energy
- Series: REX Generator Ground Fault Injection System (Match with REX011 injection transformer + REG216/REG316*4 generator protection IED)
- Core Function: Special signal injection power unit for large synchronous generators (thermal/hydro/gas turbine), adopts offset voltage injection principle to realize 100% full stator winding + rotor winding earth fault protection (eliminates neutral zone blind spot). It generates fixed fN/4 coded square-wave injection signal, cooperates with REX011 coupling transformer and REG series generator differential protection IED to calculate insulation resistance, realize early insulation degradation warning and ground fault trip protection, effective in generator standstill, startup, rated operation and shutdown all working conditions.
- Product Type: Generator Ground Fault Signal Injection Source Unit (Separate cabinet panel mounting, matched with REX011 injection transformer as a complete set)
- Key Specs: 220V AC auxiliary power supply; fN/4 fixed injection frequency; continuous self-supervision of injection signal; dual relay fault/trip output; compatible with all generator neutral grounding modes (resistance, arc suppression coil, high-impedance grounding)
- Note: Mature legacy power plant dedicated equipment, official end-of-production; only residual factory new complete sets and fully bench-tested surplus assemblies are supplied for thermal power, hydropower, combined cycle unit maintenance retrofits. Must be used together with REX011 injection transformer and REG216/REG316*4 generator protection relay, cannot operate independently.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Standard OEM Part Number | HESG324426R1 |
| Auxiliary Control Supply | 220 VAC 50/60Hz; Max power consumption 35VA |
| Injection Signal Characteristic | Fixed fN/4 square wave coded offset voltage signal |
| Measurable Earth Fault Resistance Range | 0 ~ 100kΩ continuous calculation |
| Protection Coverage | 100% full stator winding (no neutral blind zone) + full rotor winding earth fault monitoring |
| Operating Condition Adaptability | Valid for generator standstill, run-up, full load, rundown all operating states |
| Built-in Self-Supervision Logic | Real-time monitoring injection signal amplitude, frequency, loop integrity; self-alarm for signal loss/loop open circuit |
| Front Panel Status Indicators | Green RUN (device ready), Yellow INJECT (signal output), Red FAULT (overload/loop failure) LED indicator |
| Control I/O Terminals | 1 group enable/disable control input; 2 groups isolated relay output (fault alarm, protection trip) |
| Compatible Matching Devices | Injection transformer REX011; Generator protection IED REG216 / REG316*4 |
| Allowed Generator Neutral Earthing Modes | Resistance grounding, resonant Petersen coil grounding, high-impedance neutral grounding |
| Ambient Operating Temperature | -20 ℃ ~ +55 ℃ cabinet continuous operation; storage -40 ℃ ~ +85 ℃ |
| Enclosure Protection Grade | Front panel IP54, rear terminal compartment IP20 |
| Installation Form | Standard panel embedded mounting |
| Overall Dimensions | 254 mm W × 203 mm H × 130 mm D |
| Net Weight | 7.35 kg |
| Compliance Standards | IEC 60034-1 (generator standard), IEC 60255 protection standard, KEMA type-tested |
Product Introduction
is the core signal source of ABB full-range generator ground fault protection system, solving the inherent defect of traditional neutral displacement voltage protection (only covers 95% stator winding, dead zone at neutral point). It injects low-frequency coded offset voltage signal into generator neutral circuit via matched injection transformer, REG series protection IED collects the feedback signal to calculate winding insulation resistance, accurately judge slight insulation aging and single-point earth fault at any position of stator/rotor winding.
The biggest advantage of injection principle: protection works normally even when the generator is completely static (zero excitation, no grid voltage), which can detect hidden winding insulation damage during shutdown maintenance, avoiding startup short-circuit accidents. Built-in full-loop self-check function, once the injection loop, transformer or wiring is abnormal, immediately outputs alarm signal to DCS/SCADA system, preventing protection failure.
Two groups of independent relay output contacts can be flexibly configured: one for light alarm (insulation resistance exceeds early warning threshold), one for heavy trip (serious ground fault, generator shutdown interlock). The whole set system is widely used in large thermal power, hydropower, gas combined cycle, wind farm doubly-fed generator and industrial self-provided power station main unit protection.
QA & Testing SOP (Transparency Building)
- Incoming Inspection: Cross-check full part number HESG324426R1 and serial number against ABB power plant spare parts database to reject mismatched counterfeit equipment; inspect front panel indicator, internal power injection circuit, terminal screw blocks and conformal PCB coating for burn marks, moisture corrosion or scratch damage; record serial number and production batch for full traceability.
- Complete Set Linkage Test: Match + injection transformer + REG316*4 generator protection IED to build a complete test bench, supply 220V AC auxiliary power, simulate 0~100kΩ variable earth resistance fault signals, continuously run 24-hour cyclic test of injection signal, self-supervision logic and trip/alarm output, verify 100% winding fault detection function.
- Electrical Insulation Test: Use insulation resistance tester to verify isolation resistance ≥10MΩ between power injection circuit, auxiliary power and control signal terminals; test chassis grounding continuity resistance ＜0.5Ω.
- Parameter & Logic Backup: Record internal hardware version of , photograph front panel enable switch and rear terminal wiring definition, export complete generator ground fault protection setting group from matched REG IED for offline backup.
- Final Packaging & Delivery: Wipe front panel shell with anti-static cloth, cover all terminal blocks with insulating protective caps, independently pack and matched into separate ESD shielding bags, attach unified printed QC test label with technician ID and full 24-hour linkage test runtime timestamp, adopt foam shockproof carton packaging for power plant long-distance transportation.
Installation Pitfalls & 4-Step Replacement Guide
Common Installation Risks
❗ Complete Set Matching Error: must be paired with dedicated injection transformer; ordinary voltage transformer cannot replace , otherwise injection signal distortion leads to protection misoperation or failure.❗ Auxiliary Power Mismatch: This model only supports 220V AC auxiliary supply; direct access to DC power supply will burn internal injection power board.❗ Injection Loop Open Circuit Risk: Disconnect neutral secondary wiring when the unit is energized will generate high induced voltage, strictly implement lockout/tagout before wiring disassembly.❗ Insulation Resistance Setting Misconfiguration: Different generator capacity corresponds to different early warning/trip resistance thresholds; wrong parameter setting will cause frequent false alarms or failure to trip.❗ ESD Damage Risk: Ungrounded contact with internal PCB injection circuit traces will damage signal generation chip, resulting in permanent loss of injection function.
4-Step Unit Replacement Guide
- Pre-install Preparation: Lock out generator neutral cabinet auxiliary AC power supply, wear certified anti-static wrist strap, photograph auxiliary power wiring, injection signal wiring to , fault/trip relay output wiring to REG IED and DCS system.
- Removal Operation: Cut off front panel enable switch, disconnect all rear terminal screw wiring, unfasten panel mounting fixing bolts, take out old unit from cabinet panel frame ( injection transformer remains fixed on neutral cabinet).
- Installation & Wiring: Fix new unit to panel frame, replicate original auxiliary power, injection loop and control signal wiring one-to-one according to photographed wiring diagram, confirm terminal torque meets ABB specification requirements.
- Power-on Commissioning Test: Restore 220V AC auxiliary power, turn on front panel enable switch, observe green RUN indicator light normally on; inject simulated earth resistance fault signal, verify yellow injection signal indicator flashes normally, REG generator IED can accurately collect fault resistance value and output corresponding alarm/trip signal, confirm DCS fault signal upload stable.
FAQ
Q: What is the complete matching combination of system?A: Three indispensable components:
- : Injection signal source main unit;
- : Injection coupling transformer (installed on generator neutral point);
- REG216 / REG316*4: Generator main protection IED (process injection signal, realize ground fault protection logic).
Q: What is the difference between traditional neutral displacement voltage ground fault protection?A: Traditional 95% neutral displacement voltage protection cannot detect ground fault near generator neutral point (5% dead zone); injection scheme realizes 100% full stator winding coverage, and can monitor insulation state when generator is shut down without excitation, which is the standard configuration for large high-value generators.
Q: Can be hot-swapped under energized auxiliary power?A: Not allowed. The internal injection circuit will generate low-frequency AC signal output after power-on; disconnection of live wiring will cause signal loop open circuit and high induced voltage, must cut off auxiliary power and implement lockout/tagout before disassembly.
Q: What warranty is applicable to stocked complete sets?A: Factory-new original complete sets (+) carry 12-month official ABB manufacturer warranty covering injection power circuit, self-supervision logic and relay output contacts. Bench-tested surplus single units/complete sets provide 6-month functional warranty; damage caused by miswiring, overvoltage impact and ungrounded ESD handling will void all warranty terms.
Q: Has ABB stopped producing ?A: / injection system is fully end-of-production; new power plant projects adopt upgraded REG670 generator protection IED with built-in injection module. only supplies spare parts maintenance for legacy REG216/ generator protection fleets.
Q: Can be used for medium voltage feeder or transformer ground fault protection?A: Not applicable. Its injection algorithm and frequency signal are specially calibrated for synchronous generator stator/rotor winding insulation characteristics; feeder/transformer ground fault protection adopts REF615/RET670 series IED without separate injection unit.
