Suitable for use as service entrance equipment For use on circuits rated up to 200K w/Class R or J fuses Easy 2 or 3 point mounting Heavy Duty Safety Switches are available in 30-1200A ratings and in Type 1,3R,12,and 4xenclosures. Both fusible and non-fusible versions are offered. They can be used on circuits that are rated through 200K when protected by or used w/Class R or J fuses. They feature quick make and break operation and visible blade construction. 100-Amp,3-pole,3-wire,600-Volt fusible safety switch NEMA type 1: enclosure is intended for indoor use primarily to provide protection against contact w/the enclosed equipment in locations where unusual service conditions do not exist Quick-make,quick-break operating mechanism that ensures positive o.