12.5kA High-Energy 1+1 Protection Structure for TT/IT Systems

Product Overview

The NPS01-FBC12.5 AC 1+1P Surge Protective Device is a high-current Type 1+2 combined protection unit designed specifically for TT and IT grounding systems. It complies with EN/IEC 61643-11 and GB/T 18802.11 standards and provides Class I+II surge protection performance.

The product adopts a phase line plus neutral line 1+1 protection structure, with independent L-PE and N-PE discharge paths. With an impulse current capability of 12.5kA (10/350μs), it is especially suitable for single-phase power systems with isolated neutral points or high-impedance grounding requirements.

The compact 36mm design supports standard 35mm DIN rail installation, with Uc voltage options from 275V to 440V. It is widely used in chemical plants, mining facilities, rail transportation, and other applications requiring highly reliable power continuity.

Dedicated N-PE Graphite Spark Gap for Zero Leakage Neutral Operation

The phase protection circuit combines a large graphite spark gap with a high-energy zinc oxide varistor. The N-PE circuit uses a dedicated high-current graphite discharge module, ensuring minimal leakage current and no power consumption during normal operation.

The coordinated multi-stage protection structure effectively handles lightning impulses and switching overvoltage while preventing unnecessary follow current.

High-quality components undergo strict temperature, humidity, and aging tests to ensure excellent environmental resistance and long-term reliability.

The conductive system uses high-purity T2 copper busbars with tin-plated surfaces, providing strong current carrying capability, low resistance, and reduced heat generation.

The UL94V-0 flame-retardant housing provides reliable insulation protection. Automated production processes and complete high-current testing ensure consistent performance.

Compact 36mm Design with High Energy Density

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 (100ns in NPE mode).

Recommended for use with a 160A gG backup fuse, the product provides coordinated protection and improves system reliability.

The built-in thermal disconnector and visual status indicator clearly display operating conditions. Green indicates normal operation, while red indicates module failure.

Optional remote alarm contacts support centralized monitoring systems. The unit operates from -40℃ to +80℃ with 5%-95% humidity tolerance and supports 4-25mm² wiring.

The 36mm compact structure provides high energy handling capability while saving installation space, making it an efficient protection solution for TT and IT power systems.

Model	NPS01-FBC12.5/275/1+1	NPS01-FBC12.5/320/1+1	NPS01-FBC12.5/385/1+1	NPS01-FBC12.5/440/1+1
SPD Test Category	Type1+2/ClassI+II(EN/IEC61643-11,GB/T18802.11)
Maximum Continuous Operating Voltage Uc (Current Type: a.c.)	275V(NPE255V)	320V(NPE255V)	385V(NPE255V)	440V(NPE255V)
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 (N-PE: 100ns)
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: 36×87×87mm
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.