Pepperl+Fuchs NJ Series Inductive Sensors: NJ1,5-8GM-N

Technical Dossier

Product Details And Specifications

Pepperl+Fuchs NJ Series Inductive Sensors: Comprehensive Module Range and Technical Overview

The Pepperl+Fuchs NJ Series represents one of the most widely deployed families of inductive proximity sensors in global heavy industry. Installed across petrochemical refineries, nuclear power auxiliary systems, offshore platforms, and continuous-process chemical plants, NJ Series sensors are recognized for their robust cylindrical housing, standardized M8/M12/M18/M30 thread formats, and reliable non-contact detection of ferrous and non-ferrous metal targets. The series covers sensing ranges from 1 mm to 30 mm, with variants supporting DC 2-wire, DC 3-wire PNP/NPN, and AC/DC universal configurations. Their compliance with IEC 60947-5-2 and EN 60947-5-2 makes them a default specification in European and Asian industrial automation projects. DriveKNMS maintains active stock and sourcing channels for the full NJ catalog, including long-discontinued part numbers.

The Evolution of NJ Series Architecture

The NJ Series was introduced by Pepperl+Fuchs in the early 1980s as a standardized inductive sensor line designed to replace relay-based limit switches in machine tool and conveyor applications. The original NJ family used analog-output proximity circuits with discrete wiring; subsequent generations introduced IO-Link compatibility on select variants, enabling parameterization and diagnostic feedback over a single 3-wire cable without additional hardware.

Key architectural milestones include the transition from PVC-jacketed cable terminations to M12 quick-disconnect connectors (mid-1990s), the introduction of stainless-steel V2A and V4A housing options for food-grade and corrosive environments, and the addition of NAMUR-output variants (NJ…-N suffix) for use in intrinsically safe circuits in Zone 1/Zone 2 hazardous areas. The NAMUR output standard (EN 60947-5-6) is specifically relevant to the NJ1,5-8GM-N, which is designed for direct connection to NAMUR-compatible safety barriers and isolators in Ex-rated installations.

As the NJ Series has matured, many early-generation part numbers have entered end-of-life status. Pepperl+Fuchs has issued replacement recommendations for several discontinued variants, but installed base requirements in legacy DCS and SIS architectures frequently demand exact form-fit-function replacements rather than functional equivalents.

NJ Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked part numbers within the Pepperl+Fuchs NJ Series. Each entry includes the primary functional descriptor. SKUs are organized by housing diameter and output type.

M8 Housing (8 mm diameter):

• NJ1,5-8GM-N: M8 flush inductive sensor, 1.5 mm range, NAMUR output, for Ex Zone 1/2 applications
• NJ1,5-8GM-N-5M: M8 flush, 1.5 mm range, NAMUR output, 5 m PVC cable termination
• NJ1,5-8GK-N: M8 flush, 1.5 mm range, NAMUR output, short-body variant
• NJ1,5-8GM-E2: M8 flush, 1.5 mm range, DC 3-wire PNP NO output, standard industrial
• NJ1,5-8GM-E2-V3: M8 flush, 1.5 mm range, DC 3-wire PNP NO, V3 connector version

M12 Housing (12 mm diameter):

• NJ2-12GM-N: M12 flush, 2 mm range, NAMUR output, Ex-rated proximity sensor
• NJ4-12GM-N: M12 non-flush, 4 mm range, NAMUR output, extended sensing distance
• NJ4-12GM-E2: M12 non-flush, 4 mm range, DC 3-wire PNP NO, general purpose
• NJ4-12GK-N: M12 non-flush, 4 mm range, NAMUR output, short-body design
• NJ2-12GM40-E2-V1: M12 flush, 2 mm range, PNP NO, 40 mm extended body, M12 connector

M18 Housing (18 mm diameter):

• NJ5-18GM-N: M18 flush, 5 mm range, NAMUR output, standard hazardous area sensor
• NJ8-18GM-N: M18 non-flush, 8 mm range, NAMUR output, extended range Ex sensor
• NJ8-18GM-E2: M18 non-flush, 8 mm range, DC 3-wire PNP NO, general industrial
• NJ5-18GK-N: M18 flush, 5 mm range, NAMUR output, short-body variant

M30 Housing (30 mm diameter):

• NJ15-30GM-N: M30 non-flush, 15 mm range, NAMUR output, heavy-duty Ex proximity sensor
• NJ15-30GM-E2: M30 non-flush, 15 mm range, DC 3-wire PNP NO, standard industrial
• NJ10-30GM-N: M30 flush, 10 mm range, NAMUR output, flush-mount Ex sensor

Sourcing Hard-to-Find & Obsolete NJ Series Parts

DriveKNMS operates a dedicated procurement channel for Pepperl+Fuchs NJ Series components that have been discontinued or are subject to extended lead times through standard distribution. The NJ Series has a multi-decade installed base, and many facilities operating legacy Siemens TELEPERM, Honeywell TDC 3000, or ABB Advant DCS architectures continue to specify original NJ part numbers for maintenance and turnaround projects.

Our sourcing process for obsolete NJ variants includes verification against Pepperl+Fuchs original part number databases, cross-referencing with successor part numbers where applicable, and physical inspection of any surplus stock prior to shipment. For NAMUR-output variants such as the NJ1,5-8GM-N, we verify NAMUR switching threshold compliance (EN 60947-5-6: 1 mA / 2.1 mA switching levels) using calibrated test equipment before dispatch.

Customers requiring long-term maintenance agreements or blanket purchase orders for NJ Series sensors across multi-year plant maintenance cycles are encouraged to contact our technical sales team directly.

Quality Control for the NJ Series Range

All NJ Series sensors processed through DriveKNMS undergo a structured inspection and functional test protocol prior to shipment:

• Visual inspection: Housing thread condition, cable jacket integrity, connector pin condition, and label legibility are checked against OEM specifications.
• Electrical continuity: Supply voltage, output switching state, and leakage current are measured at rated operating voltage (for NAMUR variants: 8 VDC per EN 60947-5-6).
• Switching distance verification: Sensing range is confirmed using a standard Fe360 target at rated operating distance and hysteresis boundaries.
• NAMUR threshold test: For -N suffix variants, open-circuit and short-circuit current levels are verified to confirm compatibility with downstream safety barriers (e.g., Pepperl+Fuchs Z728, MTL7706).
• Temperature cycling: Spot-checked units are subjected to thermal cycling per IEC 60068-2-14 to verify seal integrity and output stability.

Test records are retained per shipment and available upon request for SIL-rated maintenance documentation packages.