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Mercury 5 x 20mm F1A Quick Blow Fuses - 1A 250V

£149
The RRP is the manufacturer's recommended retail price of the item.
Limited Stock
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Description

The Mercury F1A is a 5x20mm quick blow glass cartridge fuse rated at 1A 250V, designed to disconnect circuits within milliseconds when current exceeds the rated threshold. The glass body allows visual inspection of the internal element to confirm whether the fuse has blown, while the nickel-plated metal end caps provide reliable contact in standard fuse holders and panel clips.

Quick blow fuses are suited to protecting sensitive electronics where even brief overcurrent surges can cause component damage, such as audio equipment power supplies, control boards, and instrumentation. The 1A rating makes this fuse appropriate for low-current circuits where higher-rated fuses would fail to trip before damage occurs. The 5x20mm format is a standard cartridge size fitting most European and UK fuse holders.

The 250V capacity covers standard UK mains voltage with headroom, and the IEC approval confirms compliance with international standards for electrical safety. These fuses are supplied in packs suitable for workshop stock, equipment repair, and installation work where multiple units may be needed across different appliances or control panels.

Frequently Asked

What's the difference between quick blow and slow blow fuses?

Quick blow fuses trip within milliseconds of exceeding the rated current, protecting sensitive electronics from brief surges. Slow blow fuses tolerate short-duration overloads (such as motor startup inrush) and only trip if the overcurrent is sustained for several seconds. The F1A is a quick blow type.

Can I replace a blown fuse with a higher-rated one?

No. Using a higher-rated fuse than specified by the equipment manufacturer removes the intended protection and can result in component damage or fire. Always replace a blown fuse with the same rating and type.

How do I know if the fuse has blown?

The glass body allows you to see the internal wire element. If the fuse has blown, the wire will be broken or discoloured. If you cannot see the element clearly, test with a multimeter set to continuity or resistance mode across the two end caps.

Are these suitable for mains voltage circuits?

Yes. The 250V rating covers UK mains voltage (230V nominal). However, the 1A current rating is low for most mains appliances — check the equipment specification to confirm the correct fuse rating before fitting.

Shipping & Returns

Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

To arrange a return, call us on 020 8149 5199 or use our contact page.

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    Description

    The Mercury F1A is a 5x20mm quick blow glass cartridge fuse rated at 1A 250V, designed to disconnect circuits within milliseconds when current exceeds the rated threshold. The glass body allows visual inspection of the internal element to confirm whether the fuse has blown, while the nickel-plated metal end caps provide reliable contact in standard fuse holders and panel clips.

    Quick blow fuses are suited to protecting sensitive electronics where even brief overcurrent surges can cause component damage, such as audio equipment power supplies, control boards, and instrumentation. The 1A rating makes this fuse appropriate for low-current circuits where higher-rated fuses would fail to trip before damage occurs. The 5x20mm format is a standard cartridge size fitting most European and UK fuse holders.

    The 250V capacity covers standard UK mains voltage with headroom, and the IEC approval confirms compliance with international standards for electrical safety. These fuses are supplied in packs suitable for workshop stock, equipment repair, and installation work where multiple units may be needed across different appliances or control panels.

    Frequently Asked

    What's the difference between quick blow and slow blow fuses?

    Quick blow fuses trip within milliseconds of exceeding the rated current, protecting sensitive electronics from brief surges. Slow blow fuses tolerate short-duration overloads (such as motor startup inrush) and only trip if the overcurrent is sustained for several seconds. The F1A is a quick blow type.

    Can I replace a blown fuse with a higher-rated one?

    No. Using a higher-rated fuse than specified by the equipment manufacturer removes the intended protection and can result in component damage or fire. Always replace a blown fuse with the same rating and type.

    How do I know if the fuse has blown?

    The glass body allows you to see the internal wire element. If the fuse has blown, the wire will be broken or discoloured. If you cannot see the element clearly, test with a multimeter set to continuity or resistance mode across the two end caps.

    Are these suitable for mains voltage circuits?

    Yes. The 250V rating covers UK mains voltage (230V nominal). However, the 1A current rating is low for most mains appliances — check the equipment specification to confirm the correct fuse rating before fitting.

    Shipping & Returns

    Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

    Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

    To arrange a return, call us on 020 8149 5199 or use our contact page.