Eaton HTP-SC16M / MTL – Surge Protection for Signal Lines

Protection Technology

The HTP-SC16M utilizes a hybrid protection circuit combining fast‑acting suppression diodes and gas discharge tubes (GDT). This multi‑stage design ensures very low let‑through voltage (clamping) and high surge current handling capability. The device responds within nanoseconds to transients, diverting harmful energy away from costly field instruments and control cards.

Key Features

• Universal Application: Suitable for 2‑, 3‑, or 4‑wire transmitters, RTDs, thermocouples, and digital signals.

• Low Insertion Loss: Minimal impact on signal integrity; typical series resistance<10 Ω.

• High Surge Rating: Withstands 10 kA 8/20 µs impulse current per channel (line to ground).

• Compact Housing: Slim 6 mm wide package for high‑density DIN‑rail mounting, saving panel space.

• Plug‑In Terminals: Removable screw terminals for easy wiring and maintenance without disconnecting wires.

• Grounding: Direct DIN‑rail grounding or separate ground terminal.

Technical Specifications

• Nominal Voltage (DC): 24 V (max. continuous operating voltage 30 V)

• Max. Load Current: 300 mA per line

• Series Resistance:<10 Ω per line

• Capacitance: < 100 pF (line to line)

• Protection Modes: Line‑Line, Line‑Ground

• Response Time: < 1 ns

• Operating Temperature: -40°C to +80°C

• Enclosure Material: Polyamide, UL94 V‑0

• Connection: Screw terminals for 0.2‑2.5 mm² (AWG 24‑12) wire

• Mounting: 35 mm DIN rail (EN 60715)

Typical Applications

The HTP-SC16M is widely used in:

• Process industries (oil & gas, chemical, pharmaceutical) – protecting field instruments from lightning strikes

• Water and wastewater treatment – safeguarding PLC and SCADA inputs

• Power generation – I/O protection in control systems

• Building automation – protecting sensors and controllers

Installation and Compliance

The device is designed for easy installation on standard DIN rails. It meets relevant standards for surge protective devices, including IEC 61643‑21. When used in conjunction with proper grounding and equipotential bonding, the HTP-SC16M ensures the integrity of your control system against transient overvoltages.

By integrating Eaton’s MTL surge protection into your signal lines, you reduce downtime and maintenance costs while increasing the reliability of your automated processes.