The cylindrical fuse holders are also approved according to UL 512. The cylindrical fuse holders are tested and approved as fuse disconnectors according to the switching device standard IEC 60947-3. They are not suitable for switching loads. Cylindrical fuse holders can be supplied with or without signal detectors. In the case of devices with signal detector, a small electronic device with LED is located behind an inspection window in the plug-in module. If the inserted fuse link is tripped, this is indicated by the LED flashing. The switching state of the fuse holder can be signaled over a laterally retrofitted auxiliary switch, which enables the integration of the fuses in the automation process. Siemens Sentron™ Cylindrical Fuse Holder, SZ NH1 Sealable, 690 VAC, 50 A, 3+N Pole, 10 to 6 AWG Wire, Surface Mount, 14 mm Fuse Length, 51 mm Fuse Dia, -5 to 40 °C, For Use With: Cylindrical Fuse System, Ceramic/Plastic, 90 mm H x 108 mm W x 70 mm D