Mersen ST-XR Series Type 1 Surge Protective Device, 240V, 50 kA

Mersen ST-XR Series Type 1 Surge Protective Device, 240V, 50 kA

The Mersen ST-XR Series Type 1 Surge Protective Device (SPD) is a UL1449 5th Edition-listed surge arrestor replacement built with TPMOV® technology for safe, reliable performance. Rated 240V L-L, this compact SPD offers a Voltage Protection Rating (VPR) of 1500V L-L (1200V L-G), an MCOV of 640V L-L (320V L-G), and a 50 kA surge rating, with flexible line- or load-side installation for branch panel or individual equipment protection. Its compact, panel-mount design makes it a practical, code-compliant upgrade wherever legacy surge arrestors need to be replaced with modern, safer surge protection technology.

Key Features

• Durable Enclosure: NEMA 4X non-metallic polycarbonate housing resists corrosion in demanding electrical environments.
• Flexible Mounting: Panel Mount installation supports line or load connection for branch panel and individual equipment protection.
• Voltage Protection: VPR of 1500V L-L / 1200V L-G safeguards connected equipment from transient surges.
• MCOV Rating: Maximum Continuous Operating Voltage of 640V L-L / 320V L-G matches 240V L-L system requirements.
• Surge Capacity: Rated 50 kA with a Nominal Discharge Current (In) of 20 kA (8/20) for dependable transient suppression.
• 3-Phase Delta Configuration: Engineered for AC systems operating at 50/60 Hz.
• LED Indication: Built-in LED indication system provides at-a-glance protection status.
• TPMOV® Technology: A safer alternative to standard MOV-based surge protection designs, engineered into the compact STXR format.

Certifications & Compliance

• UL Listed, UL1449 5th Edition Type 1 SPD
• RoHS Compliant

Technical Specifications

• Indication System Type: LED
• Indication System: Yes
• ROHS Compliant: Yes
• AC or DC: AC

Typical Applications

• Commercial and Industrial Electrical Panels
• Branch Panel Surge Protection
• Individual Equipment Protection
• 3-Phase Delta Distribution Systems
• Panel Mount Installations
• Replacement for Outdated Surge Arrestors

Why Mersen?

Mersen's ST-XR Series combines UL1449 5th Edition compliance, TPMOV® technology, and a rugged NEMA 4X polycarbonate enclosure to deliver dependable, code-compliant surge protection for professional electrical installations. With clear LED status indication and RoHS-compliant construction, the ST-XR Series is engineered for long-term reliability in demanding commercial and industrial environments. As part of the broader Mersen Surge-Trap STX product line, the ST-XR Series gives electrical contractors and facility engineers a trusted, standards-based path to modernizing surge protection on 3-Phase Delta AC systems.