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Mercury 6 x 32mm T4A Slow Blow Fuses - 250V

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

The Mercury T4A is a 6 x 32mm slow blow (time-delay) glass tube fuse rated at 4A and 250V, designed to withstand brief inrush currents before blowing. The slow blow characteristic allows the fuse to ride out the initial current surge when motors, transformers or capacitors power on, then provide overcurrent protection during normal operation.

Fitted in small domestic appliances, AV amplifiers, test equipment and control panels where switch-on current spikes would trip a fast-acting fuse prematurely, the T4A uses a coiled wire element inside a glass tube with nickel-plated brass end caps. The wire coil absorbs thermal energy during transient overloads before melting under sustained overcurrent, giving protection without nuisance tripping.

The 6 x 32mm dimension is an IEC standard size, allowing the fuse to fit into panel-mount fuseholders, PCB clips and inline holders rated for this form factor. The glass tube construction allows visual inspection of the element after a fault — a broken wire with scorch marks indicates a genuine overload, while a clean break suggests mechanical failure or installation error.

Frequently Asked

What does slow blow mean?

Slow blow (also called time-delay) means the fuse can withstand brief current surges above its 4A rating without blowing, typically handling 10-20A for 1-2 seconds during motor or transformer start-up. Under sustained overcurrent the element heats and melts, breaking the circuit.

What's the difference between slow blow and fast-acting fuses?

Fast-acting fuses blow immediately when current exceeds their rating, making them suitable for resistive loads that draw steady current. Slow blow fuses tolerate short-duration surges, making them better for inductive loads (motors, transformers) that draw high current on switch-on.

Can I use a 5A fuse instead?

Only if the device manufacturer specifies a 5A rating. Using a higher-rated fuse can allow sustained overcurrent to damage the equipment or create a fire hazard. Always replace fuses with the same rating.

Are these sold individually or in packs?

Check the product specifications — fuses are typically sold in packs of 5, 10 or 100 depending on the SKU.

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 T4A is a 6 x 32mm slow blow (time-delay) glass tube fuse rated at 4A and 250V, designed to withstand brief inrush currents before blowing. The slow blow characteristic allows the fuse to ride out the initial current surge when motors, transformers or capacitors power on, then provide overcurrent protection during normal operation.

    Fitted in small domestic appliances, AV amplifiers, test equipment and control panels where switch-on current spikes would trip a fast-acting fuse prematurely, the T4A uses a coiled wire element inside a glass tube with nickel-plated brass end caps. The wire coil absorbs thermal energy during transient overloads before melting under sustained overcurrent, giving protection without nuisance tripping.

    The 6 x 32mm dimension is an IEC standard size, allowing the fuse to fit into panel-mount fuseholders, PCB clips and inline holders rated for this form factor. The glass tube construction allows visual inspection of the element after a fault — a broken wire with scorch marks indicates a genuine overload, while a clean break suggests mechanical failure or installation error.

    Frequently Asked

    What does slow blow mean?

    Slow blow (also called time-delay) means the fuse can withstand brief current surges above its 4A rating without blowing, typically handling 10-20A for 1-2 seconds during motor or transformer start-up. Under sustained overcurrent the element heats and melts, breaking the circuit.

    What's the difference between slow blow and fast-acting fuses?

    Fast-acting fuses blow immediately when current exceeds their rating, making them suitable for resistive loads that draw steady current. Slow blow fuses tolerate short-duration surges, making them better for inductive loads (motors, transformers) that draw high current on switch-on.

    Can I use a 5A fuse instead?

    Only if the device manufacturer specifies a 5A rating. Using a higher-rated fuse can allow sustained overcurrent to damage the equipment or create a fire hazard. Always replace fuses with the same rating.

    Are these sold individually or in packs?

    Check the product specifications — fuses are typically sold in packs of 5, 10 or 100 depending on the SKU.

    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.