{"product_id":"mercury-5-x-20mm-t6-3a-slow-blow-fuse-250v-time-delay","title":"Mercury 5 x 20mm T6.3A Slow Blow Fuse - 250V Time-Delay","description":"\u003ch5\u003eDescription\u003c\/h5\u003e\n\u003cp\u003eThe Mercury T6.3A is a slow blow fuse in a 5 x 20mm glass cartridge body with nickel-plated brass end caps, rated at 250V AC. The time-delay element inside the glass tube allows brief inrush currents to pass without blowing while still protecting the circuit from sustained overloads above 6.3A.\u003c\/p\u003e\n\u003cp\u003eDesigned for equipment with moderate startup currents such as small motors, power supplies, transformers and audio amplifiers, the slow blow characteristic prevents nuisance blowing during the initial energisation period when inductive loads briefly draw several times their running current. Once the equipment is running and current stabilises below the 6.3A rating, the fuse holds indefinitely. If a fault causes sustained overcurrent, the fuse element melts and breaks the circuit.\u003c\/p\u003e\n\u003cp\u003eThe 5 x 20mm dimension is a standard cartridge fuse size found in panel-mount fuseholders, inline cable fuseholders and PCB-mount fuse clips across consumer electronics, industrial control panels and lighting equipment. The glass body allows visual inspection of the fuse element — a broken or discoloured element indicates the fuse has blown. These fuses comply with IEC 60127 safety standards for low-voltage fuses in equipment.\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 (also called time-delay or anti-surge) fuses are designed to tolerate brief current spikes above the rated value without blowing, while still protecting against sustained overloads. This is useful for equipment with inductive loads like motors or transformers that draw several times their normal current for a fraction of a second when first powered on.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I replace a fast-blow fuse with a slow blow?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNot without understanding the circuit requirements. Fast-blow fuses provide tighter overcurrent protection and are specified where immediate cutoff is needed for sensitive components. Replacing a fast-blow with a slow blow may allow damaging currents to persist longer than the circuit was designed for. Replace fuses with the same rating and time-delay characteristic unless you know the circuit can safely accept the change.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat does T6.3A mean?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eT indicates time-delay (slow blow) characteristic. 6.3A is the continuous current rating — the maximum current the fuse can carry indefinitely without melting. The fuse will tolerate brief spikes above 6.3A but will blow if overcurrent is sustained.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAre these suitable for DC circuits?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThese fuses are rated at 250V AC. Using them in DC circuits is possible but the DC voltage rating is lower than the AC rating due to arc suppression differences. For DC applications consult the manufacturer datasheet to confirm the appropriate voltage deration.\u003c\/p\u003e","brand":"AVSL","offers":[{"title":"Default Title","offer_id":45313486389515,"sku":"787.018UK","price":1.49,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/787018UK_LB1_2c28bbf3-c225-452b-bc68-48f502aebfee.jpg?v=1715194149","url":"https:\/\/niori.co.uk\/products\/mercury-5-x-20mm-t6-3a-slow-blow-fuse-250v-time-delay","provider":"Niori","version":"1.0","type":"link"}