Mersen STP480YN07M 480V Pluggable Surge Protective Device

Product Description

The MERSEN STP480YN07M is a pluggable surge protective device (SPD) rated for 480Y/277V AC systems, designed to suppress transient voltage surges and protect downstream equipment from damage. Built on Mersens patented TPMOV technology, this thermally protected MOV design eliminates the need for additional upstream overcurrent protection devices. The unit carries UL 1449 4th Edition approval and delivers a nominal discharge current of 20 kA with a short circuit current rating of 200,000 amps. Response time is under 25 nanoseconds. Licensed electricians install this device in commercial and industrial panel applications where reliable surge suppression and minimal footprint are both required.

The STP480YN07M is suited for 480Y/277V, 4-pole, 5-wire AC distribution systems operating at 50 or 60 Hz. Its DIN rail mounting profile allows direct installation inside existing enclosures without dedicated panel space. The integrated microswitch indicator provides local visual status confirmation, and the remote indicator option allows status signaling to critical control circuitry, making it appropriate for building automation panels, industrial control cabinets, and similar installations where system uptime monitoring is a priority.

Key Features

• TPMOV technology provides thermally protected MOV operation, removing the need for separate overcurrent protection
• UL 1449 4th Edition listed fail-safe, no-fuse design
• Short circuit current rating of 200,000 amps supports high-fault-current service entrance and feeder applications
• Nominal discharge current of 20 kA with response time under 25 nanoseconds
• DIN rail mountable with compact footprint: 4.19 inches long, 2.76 inches wide, 2.81 inches tall
• Microswitch indicator and remote indicator option for integration with control circuitry
• Pluggable module design simplifies field replacement without rewiring the base

Compatibility

Designed for use on 480Y/277V, 4-pole, 5-wire AC distribution systems as a Type 1 surge protective device. Suitable for DIN rail panel installations in commercial and industrial electrical systems operating at 50 or 60 Hz.

Installation Notes

Installation must be performed by a licensed electrician in accordance with the NEC and applicable local codes. De-energize and lock out the panel before connecting or removing the SPD module. The pluggable design allows the protective module to be swapped in the field without disturbing the base wiring. Verify that the system voltage, frequency, and pole configuration match the device rating before energizing.