RSH-50 Surge Protective Device (SPD) for Single-Phase System 120/240 VAC Type 1. Uses long-lasting gas discharge tube technology and TFMOV (thermally fused metal oxide varistor) technology. Protect HVAC equipment from up to 50,000-amp single surges and up to 10,000-amp repetitive surges. This Type 1 Device - can be mounted anywhere in the electrical system. Green LED easily indicates protection. Weather-rated under NEMA 4X. Max discharge current per phase - 50kA (1 hit survivability). Nominal discharge current - 10kA (15 hits survivability). Short circuit current - 200kA.