{"product_id":"mercury-5-x-20mm-t12a-slow-blow-fuses-250v","title":"Mercury 5 x 20mm T12A Slow Blow Fuses - 250V","description":"\u003ch5\u003eDescription\u003c\/h5\u003e\n\u003cp\u003eThe Mercury T12A is a 12-amp slow blow fuse in a 5 x 20mm glass cartridge format, rated for 250V AC circuits. The slow blow (time-delay) characteristic allows the fuse to tolerate short-term current surges from motor startup, transformer inrush or capacitive loads without breaking the circuit, while still opening rapidly on sustained overloads above the rated 12A.\u003c\/p\u003e\n\u003cp\u003eDesigned for use in audio amplifiers, PA systems, powered speakers, mains-powered lighting equipment and general electronic devices where inrush current can briefly exceed the steady-state operating current. The 5 x 20mm cartridge size is a standard European format found in IEC-compliant mains input modules, inline fuse holders and equipment back panels. Each fuse uses nickel-plated brass end caps and a sand-filled glass tube for arc suppression when the element breaks.\u003c\/p\u003e\n\u003cp\u003eThe T12A rating means the fuse will hold 12A continuously at ambient temperature and will open within a defined time window on overcurrent events. The delay characteristic is calibrated to tolerate typical startup transients that last 10-50 milliseconds without nuisance tripping. IEC compliant construction ensures compatibility with standard fuse clips and holders across equipment from different manufacturers.\u003c\/p\u003e\n\u003ch5\u003eFrequently Asked\u003c\/h5\u003e\n\u003cp\u003e\u003cstrong\u003eWhat does \"slow blow\" mean?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSlow blow (or time-delay) fuses tolerate brief current surges above the rated amperage without breaking, but still open on sustained overloads. This prevents nuisance tripping from motor startup, transformer inrush or capacitor charging transients.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this suitable for 240V UK mains?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. The 250V rating covers UK mains voltage (230V nominal) with headroom for voltage variation. The fuse is designed for use in IEC mains input modules and equipment back panels.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow many fuses are in the pack?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003ePack quantity is not specified in the product data. Contact us to confirm pack size before ordering if you need a specific quantity for a project or installation.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I replace a fast-blow fuse with this slow blow type?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOnly if the equipment manufacturer specifies a slow blow fuse is acceptable. Replacing a fast-blow with a slow-blow reduces overcurrent protection speed and may allow fault conditions to persist longer than the circuit design intended.\u003c\/p\u003e","brand":"AVSL","offers":[{"title":"Default Title","offer_id":45313486848267,"sku":"787.021UK","price":1.49,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/787021UK_LB1_7b7573c9-c310-4ff1-9d61-4db0441c5658.jpg?v=1715194159","url":"https:\/\/niori.co.uk\/products\/mercury-5-x-20mm-t12a-slow-blow-fuses-250v","provider":"Niori","version":"1.0","type":"link"}