Three Phase Surge Arrester for Transformer Low-Voltage Side Protection

Three Phase Surge Arrester by Prosurge: Transformer Low-Voltage Side Protection

Three phase distribution transformers require robust protection against lightning strikes and switching transients. A three phase surge arrester from Prosurge provides the necessary protection for the low-voltage secondary side of pole-mounted and pad-mounted three phase transformers. The Prosurge PSM40 series three phase surge arrester is designed specifically for this application, delivering 40kA max discharge current (8/20µs) and compliance with UL1449 5th Edition, IEEE Std C62.11, and IEC/EN 61643-11.

The Prosurge three phase surge arrester uses UL-certified high-performance MOVs as core components. This Prosurge three phase surge arrester achieves low voltage protection levels and fast ≤25ns response time. Each Prosurge three phase surge arrester in the series maintains leakage current below 0.1mA and requires no follow current. Prosurge has engineered this three phase surge arrester specifically for three phase WYE/Delta configured distribution transformers.

Three Phase WYE/Delta Voltage Configurations from Prosurge

A three phase surge arrester must match the operating voltage of the protected three phase transformer. Prosurge offers two distinct three phase surge arrester models in the PSM40 series for common South/Middle/North American three phase WYE power systems or 240V Delta/480V Delta power system.  The Prosurge three phase surge arrester is ideal for transformer low-voltage side protection.

The Prosurge PSM40-240/3P three phase surge arrester is designed for 120/208Vac and 127/220Vac three phase WYE power systems or 240V Delta power system, with a max continuous operating voltage (Uc) of 275Vac. This Prosurge three phase surge arrester achieves a voltage protection level below 1.8kV at 20kA and withstands temporary overvoltage (TOV) of 335Vac for 5 seconds.

The Prosurge PSM40-480/3P three phase surge arrester is designed for 220/380Vac to 277/480Vac three phase WYE power systems or 480V Delta power system, with a max continuous operating voltage (Uc) of 480Vac or 550Vac. This Prosurge three phase surge arrester delivers voltage protection below 2.0kV at 20kA and handles temporary overvoltage (TOV) of 504Vac for 5 seconds. .

Rugged Construction for Outdoor Three Phase Transformer Installation

A three phase surge arrester installed on a pole or pad three phase transformer must survive harsh environmental exposure. Prosurge builds the PSM40 series three phase surge arrester using high-grade 304 stainless steel housing with IP68 (NEMA6P) rating. This Prosurge three phase surge arrester enclosure is both waterproof and flame-resistant, ensuring long-term reliability from –40°C to +85°C.

The Prosurge three phase surge arrester arrives pre-wired with 30cm UL1015 10AWG leads. Each Prosurge three phase surge arrester includes three black leads for L1, L2, L3 phases and one white lead for neutral/ground. Each Prosurge three phase surge arrester lead comes with lug terminals (5.5-12) for direct connection to the transformer low-voltage side. Installation of this Prosurge three phase surge arrester requires only basic tools and screws for mounting.

The Prosurge three phase surge arrester measures 80x45x34mm, making this Prosurge three phase surge arrester compact enough for installation inside transformer enclosures. The epoxy resin encapsulation of each Prosurge three phase surge arrester provides excellent insulation and mechanical strength.

Why Choose Prosurge Three Phase Surge Arrester

Selecting a three phase surge arrester with UL1449 5th Edition certification guarantees compliance with the latest safety standards. Each Prosurge three phase surge arrester undergoes rigorous testing to verify 40kA Imax, 5kA In, and 10kV Uoc ratings. Prosurge maintains strict quality control throughout the production of every three phase surge arrester.

The Prosurge three phase surge arrester family is task-rated as Light Duty per UL1449, making this Prosurge three phase surge arrester ideal for transformer low-voltage side protection. Whether protecting a 208Y/120V transformer or a 480Y/277V transformer, the Prosurge PSM40 series three phase surge arrester delivers reliable surge suppression.

For applications requiring status indication, Prosurge offers the PSM40S series three phase surge arrester with LED failure indicator.

Contact Prosurge technical team to select the correct three phase surge arrester for your specific three phase transformer application.