12.5kA High-Current Three-Phase Protection for PV Inverters and Industrial Drives

Product Overview

The NPS01-FBC12.5 AC 3P Surge Protective Device is a Type 1+2 combined high-energy surge protection unit designed for three-phase three-wire power distribution systems. Manufactured according to EN/IEC 61643-11 and GB/T 18802.11 international standards, it meets Type 1+2 / Class I+II protection requirements.

The product adopts a three-pole modular structure with independent L1/L2/L3 discharge paths. With an impulse current capability of 12.5kA (10/350μs), it is designed to handle high-energy lightning surges and switching overvoltage in demanding industrial environments.

The 54mm compact modular design supports standard 35mm DIN rail installation, with Uc voltage options ranging from 275V to 440V. It is widely applied in photovoltaic inverter systems, industrial variable-frequency drives, chemical plants, metallurgy equipment, rail transportation, and other three-phase power distribution applications.

Independent High-Capacity Discharge Paths for Phase-to-Phase and Phase-to-Ground Protection

Each pole integrates a large-capacity graphite spark gap and high-energy zinc oxide varistor in a coordinated protection structure. The independent three-phase design provides effective suppression of both phase-to-phase and phase-to-ground overvoltage caused by direct lightning strikes and induced surges.

The multi-stage protection system enables efficient energy coordination, allowing lightning energy and switching surges to be discharged in stages while reducing residual voltage.

High-performance components are selected through strict high-temperature aging, humidity cycling, and impulse testing to ensure strong energy endurance, low leakage current, and long service life.

The conductive system uses high-purity T2 copper busbars with tin-plated surfaces, providing low contact resistance, excellent conductivity, and reduced temperature rise during high-current discharge.

The enclosure adopts UL94V-0 flame-retardant thermoplastic material with IP20 protection. Automated manufacturing processes and 100% high-current testing ensure stable quality and reliable operation.

Industrial-Grade Reliability with Wide Temperature Operation

The device provides 20kA (8/20μs) nominal discharge current and 50kA maximum discharge current. The voltage protection level is as low as 1.2kV, with a response time of ≤25ns, providing fast surge response and effective voltage limitation.

Each pole is equipped with an independent thermal disconnector and red/green status indicator. Green indicates normal operation, while red indicates that the corresponding module requires replacement, allowing quick fault identification.

Optional remote signaling contacts support AC 250V/0.5A output and can be integrated into SCADA or monitoring systems for remote status management.

The unit operates reliably from -40℃ to +80℃ with 5%-95% humidity tolerance and supports 4-25mm² conductors, making it a high-reliability protection solution for industrial three-phase systems.

Model	NPS01-FBC12.5/275/3	NPS01-FBC12.5/320/3	NPS01-FBC12.5/385/3	NPS01-FBC12.5/440/3
SPD Test Category	Type1+2/ClassI+II(EN/IEC61643-11,GB/T18802.11)
Maximum Continuous Operating Voltage Uc (Current Type: a.c.)	275V	320V	385V	440V
Lightning Impulse Current (10/350μs) [L-PE, N-PE] Iimp	12.5kA	12.5kA	9kA	9kA
Nominal Discharge Current (8/20μs) [L-PE, N-PE] In	20kA
Maximum Discharge Current (8/20μs) [L-PE, N-PE] Imax	50kA
Voltage Protection Level [L-PE, N-PE] Up	1.2kV	1.3kV	1.5kV	1.7kV
Response Time	≤25ns
Backup Fuse	160A gG Fuse
Remote Signal Alarm	Normally Open and Normally Closed Contact Terminals
Remote Alarm Signal Energy Un/In	AC: 250V/0.5A; 125V/1A; DC: 30V/0.1A
Remote Alarm Signal Connection Wire	0.5mm² to 1.5mm²
Remote Contact Type	Floating Changeover Contact
Temperature and Humidity Range	-40℃ to +80℃; 5%~95%
Disconnector Operation Indicator	Red: Failed; Green: Normal
Minimum Installation Conductor Cross-Section Area (L, N, PE)	4mm² Solid Wire / Flexible Wire
Maximum Installation Conductor Cross-Section Area (L, N, PE)	25mm² Standard Wire / Flexible Wire
Installation Method	35mm Standard DIN Rail
Enclosure Material	440
Enclosure Protection Degree	IP20
Dimensions	W×L×H: 54×87×87mm
Note: The above products can be optionally equipped with a remote signaling function. Products with remote signaling will have "/FM" added after the original model number, such as NPS01-FBC7/275/1/FM.