NEH - Cable-Suspended Conductive Level Switch

Flexible Cable-Suspended Conductive Level Switch for Industrial Applications

The KOBOLD NEH Series cable-suspended conductive level switch delivers versatile monitoring for conductive liquids in tall tanks or deep vessels. Tailored for applications with limited overhead access, this suspended electrode model uses flexible cables with weighted ends for stability. Neoprene cables with PVC-coated weights extend up to 100 ft, while PTFE cables with PTFE-coated weights reach up to 30 ft, allowing extended range where rigid probes are impractical.

Electrodes available in 316Ti stainless steel, Hastelloy®, or titanium and fittings in polypropylene or PTFE provide options for a variety of media including corrosive or harsh chemicals. Housings available in polycarbonate or aluminum provide IP65 protection. The NEH can handle operating pressures up to 90 PSIG and temperatures up to 140°F for Neoprene cables or 300°F for PTFE cables. The NEH is available as a single measuring probe with a 1/2” NPT or as a multipoint probe with a 1-1/2” NPT supporting up to six measuring points.

How the NEH Works: Conductive Measurement Principle

The KOBOLD NEH cable-suspended conductive level switch relies on electrical detection for accurate sensing in conductive fluids with a minimum of 20 µS/cm. Liquid contact at the electrode tip, insulated along the cable except for the exposed end, closes a low-voltage AC circuit (10 VAC, max 0.5 mA) between the sensing probe and ground reference, such as the vessel wall for conductive tanks or a ground electrode for insulating tanks.

When the circuit between the probe and reference is closed, it is detected by the relay Adjustable sensitivity from 0–50 kΩ via a potentiometer allows precise adaptation for different liquid conductivity and prevents false signals from foam or residues. In multipoint setups, each independent cable electrode signals its setpoint, activating SPDT relays for automated functions like pumping or alarming. Per specifications, the clad design prevents bridging in misty conditions, offering repeatable operation across extended lengths for reliable tank management.

Relay Module Requirements - Ordered Separately

The KOBOLD NEH conductive level switch requires a separate relay/power supply module to complete the system. These DIN-rail mountable units process the conductivity signal from the electrodes and provide relay outputs for direct integration with control systems, pumps, or alarms. Relays are configured to match your specific voltage requirements and number of monitoring points.

Available relay modules support single-point or multipoint configurations with power supply options of 24, 110, or 230 VAC (±15%, 50–60 Hz). Each module provides one or two independent SPDT relay outputs rated for 250 VAC at 5 A maximum, enabling fail-safe switching for high or low level alarms.

Installation is straightforward: the compact relay module mounts on standard DIN rail in your control panel, connects to the NEH probe via shielded cable, and provides screw-terminal outputs for easy wiring. The IP40-rated enclosure protects internal components in typical industrial electrical environments. When ordering, specify the number of sensing points (1–6), required voltage, and desired relay configuration to ensure seamless system integration.

Key Features and Performance Advantages

The NEH Series excels in applications needing reach and adaptability, with its suspended cable electrodes providing installation ease in confined spaces while ensuring durability in aggressive media. Single or multi-electrode options integrate via NE-104/304 relays for single/dual-channel control, supporting switching outputs in PLC environments.

• Extended cable lengths up to 100 ft for deep-tank access.
• No moving parts, suitable for particulate-heavy or viscous conductive liquids.
• Up to six setpoints for full overflow, low-level, or pump control.
• Corrosion-resistant materials: stainless steel, Hastelloy C, titanium with Neoprene/PTFE cladding.
• Low-voltage operation (10 VAC) and adjustable sensitivity for precise detection.
• Compact IP65 housing and DIN-rail relays for versatile mounting.

Build America, Buy America (BABA) Compliance

The KOBOLD NEH cable-suspended conductive level switch is manufactured in the USA and fully BABA compliant, qualifying for federal infrastructure projects under the IIJA with domestically sourced, high-integrity components.

Technical Specifications Overview

• Minimum Conductivity and Sensitivity: Adjustable sensitivity 0-50 kΩ for liquids ≥20 µS/cm conductivity.
• Pressure Ratings: 90 PSIG max across fittings (PP, PTFE, SS).
• Temperature Limits: 140°F Neoprene cable; 300°F PTFE; relay ambient -4 to 140°F.
• Materials: Electrodes: 316Ti stainless steel, Hastelloy® C, titanium; cables/weight: Neoprene/PVC (Ø0.23 in), PTFE/PTFE (Ø0.08 in); housings: polycarbonate, aluminum, or without.
• Electrical: Power: 24/110/230 VAC ±15%, 50-60 Hz; NE-104 2 VA, NE-304 4 VA consumption; 1-2 SPDT relays, 250 VAC/5 A max.
• Enclosure and Installation: IP65 (probe), IP40 (relay); DIN rail; cable lengths to 100 ft Neoprene, 30 ft PTFE.
• Configurations: 1-6 electrodes; ½ NPT for single point, 1-1/2-inch NPT for multipoint; with/without housing (2 m cable option).