UL 248-11:2011 pdf download – Low-Voltage Fuses – Part 11: Plug Fuses
UL 248-11:2011 pdf download – Low-Voltage Fuses – Part 11: Plug Fuses.
7.3.2 Type S plug fuses
The material for the threaded portion of a Type S plug fuse shall be of porcelain or an equivalent insulatingmaterial, and the spring contact shall be of copper alloy so designed and located that it will make electricalconnection with the ring contact of the fuseholder for Type S fuses. This upper contact is required to havetake-up action such that electrical contact,sufficient for the current rating,with the ring contact will bemaintained when the center bottom contact of the fuse contacts the center contact of the fuseholder.A fuse shall fit the adapter for its rating, and also shall not fit the other adapters, as shown in Figure E.
9.3 Verification of gono go gauging requirements for Edison-base and Type C plug fuses
9.3.1 An Edison-base or Type C fuse shall be screwed into the Go gauge, Figure C, with a torque not exceeding 0.56 Nm (5 Ibf in). When fully inserted, the center contact shall be in contact with the Surface
9.3.2 The “No-Go’ gauge. Figure 0, shall be pfaced over the screwshell portion of the fuse tested in Clause 9.3.1 using a force, including the gauge weight, not exceeding 0.25 kg (0.55 Ib). The center or bottom contact of the fuse shall not project beyond the opposite side of the gauge.
9.4 VerIfication of adapter requirements for Type S plug fuses
9.4.1 A Type S fuse shall be screwed into the adapter, Figure E. with a torque not exceeding 0.56 Nrn (5 lbfln). When fully inserted, the spring contact shall be in contact with the gauge. Additionally, the fuse can not be screwed into the adjacent sized adapters with a torque not exceeding 056 N-rn.