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Mercury 5 x 20mm F630mA Quick Blow Fuse - 250V IEC Compliant

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

The Mercury F630mA is a 5 x 20mm glass cartridge quick blow fuse rated at 630mA (0.63A) on 250V mains. Quick blow fuses are designed to interrupt the circuit rapidly when current exceeds the rated threshold, providing fast protection for sensitive electronic components, audio equipment, and lighting control circuits where even brief overcurrent events can cause damage.

Commonly used in audio amplifiers, DJ equipment, dimmer packs, LED drivers, and stage lighting controllers, the 5 x 20mm format is a standard IEC dimension that fits fuse holders in most professional audio and lighting gear. The glass tube construction allows visual inspection of the fuse element — a blown fuse shows a broken or discoloured internal wire, making fault diagnosis straightforward without needing a multimeter.

The 630mA rating sits between the more common 500mA and 1A fuses, making it useful for circuits drawing 400-550mA continuous current where a 500mA fuse would nuisance-trip and a 1A fuse would provide insufficient protection. The fuse meets IEC 127-2 dimensional and performance standards, ensuring compatibility with holders rated for 5 x 20mm cartridge fuses. Nickel-plated brass end caps provide reliable contact and corrosion resistance.

Frequently Asked

What does 'quick blow' mean?

Quick blow (also called fast-acting or F-rated) fuses respond rapidly to overcurrent, typically breaking the circuit within milliseconds when current exceeds the rating. This contrasts with slow-blow or time-delay fuses, which tolerate brief surges. Quick blow fuses are used where the protected circuit contains components that cannot survive even short overcurrent events.

Can this fuse handle inrush current?

No. Quick blow fuses are not designed to handle inrush current surges such as those from transformer or motor startup. If your circuit experiences normal startup surges, you need a slow-blow or time-delay fuse instead.

Is this fuse reusable?

No. Once blown, the fuse must be replaced. Glass cartridge fuses are single-use components. Always replace a blown fuse with the same current rating and voltage rating to maintain circuit protection.

What does the 250V rating mean?

The 250V rating is the maximum voltage at which the fuse can safely interrupt a fault current. For UK mains-powered equipment (230V), this provides adequate margin. Do not use this fuse in circuits exceeding 250V.

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 F630mA is a 5 x 20mm glass cartridge quick blow fuse rated at 630mA (0.63A) on 250V mains. Quick blow fuses are designed to interrupt the circuit rapidly when current exceeds the rated threshold, providing fast protection for sensitive electronic components, audio equipment, and lighting control circuits where even brief overcurrent events can cause damage.

    Commonly used in audio amplifiers, DJ equipment, dimmer packs, LED drivers, and stage lighting controllers, the 5 x 20mm format is a standard IEC dimension that fits fuse holders in most professional audio and lighting gear. The glass tube construction allows visual inspection of the fuse element — a blown fuse shows a broken or discoloured internal wire, making fault diagnosis straightforward without needing a multimeter.

    The 630mA rating sits between the more common 500mA and 1A fuses, making it useful for circuits drawing 400-550mA continuous current where a 500mA fuse would nuisance-trip and a 1A fuse would provide insufficient protection. The fuse meets IEC 127-2 dimensional and performance standards, ensuring compatibility with holders rated for 5 x 20mm cartridge fuses. Nickel-plated brass end caps provide reliable contact and corrosion resistance.

    Frequently Asked

    What does 'quick blow' mean?

    Quick blow (also called fast-acting or F-rated) fuses respond rapidly to overcurrent, typically breaking the circuit within milliseconds when current exceeds the rating. This contrasts with slow-blow or time-delay fuses, which tolerate brief surges. Quick blow fuses are used where the protected circuit contains components that cannot survive even short overcurrent events.

    Can this fuse handle inrush current?

    No. Quick blow fuses are not designed to handle inrush current surges such as those from transformer or motor startup. If your circuit experiences normal startup surges, you need a slow-blow or time-delay fuse instead.

    Is this fuse reusable?

    No. Once blown, the fuse must be replaced. Glass cartridge fuses are single-use components. Always replace a blown fuse with the same current rating and voltage rating to maintain circuit protection.

    What does the 250V rating mean?

    The 250V rating is the maximum voltage at which the fuse can safely interrupt a fault current. For UK mains-powered equipment (230V), this provides adequate margin. Do not use this fuse in circuits exceeding 250V.

    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.