ActronAir Surge Protector SPN208S protects compressor and control circuit electronics on compatible ActronAir systems from voltage transients caused by lightning, grid switching, and motor switching events, clamping transient voltages before they can damage PCBs, compressors, and contactors. Surge protection devices require periodic inspection -- a device that has absorbed a large transient may show no visible damage but provides no further protection. Isolate power at mains before replacing any surge protection components.