Mercury 6 x 32mm T630mA Slow Blow Fuses - Pack of 10

The Mercury T630mA is a 6 x 32mm glass cartridge fuse rated at 630 milliamps (0.63A) on 250V circuits, with a time-delay slow-blow characteristic that allows temporary overcurrent surges to pass without blowing. The glass tube construction shows a visible wire element that melts when current exceeds the rating for a sustained period, providing clear indication when the fuse has failed.

Designed for low-current electronics, control panels, audio equipment, and sensitive circuit boards where startup inrush currents are higher than running current, the time-delay action prevents nuisance blowing during switch-on while still protecting against sustained overload or short circuits. The 6 x 32mm dimension is a common European standard size that fits fuse holders in many imported appliances, testing equipment, and industrial control gear.

The nickel-plated brass caps provide reliable contact and corrosion resistance in damp or dusty environments. IEC compliance confirms the fuse meets international manufacturing and performance standards for consistent breaking capacity. The 250V rating covers both 230V mains circuits and lower-voltage DC applications where a time-delay fuse is specified.

What does T630mA mean?

The T prefix indicates a time-delay (slow-blow) characteristic, meaning the fuse tolerates brief overcurrent surges without blowing. The 630mA rating is the maximum continuous current the fuse will carry indefinitely — prolonged current above this melts the element.

How does a slow-blow fuse differ from a fast-blow?

Slow-blow fuses have a thicker element or coiled spring design that absorbs brief current spikes without melting, making them suited to circuits with motors, transformers or capacitors that draw higher current during startup. Fast-blow fuses melt almost instantly when current exceeds the rating, protecting sensitive semiconductor circuits.

What size fuse holder does this fit?

The 6 x 32mm size is a standard European cartridge fuse dimension. It fits panel-mount or PCB-mount fuse holders marked 6.3 x 32mm or 1/4 x 1-1/4 inch (the imperial equivalent). Check the existing fuse before ordering to confirm dimension.

Can this be used in 12V or 24V DC circuits?

Yes. The 250V rating is the maximum voltage, so the fuse can be used safely on any DC or AC circuit up to 250V where a 630mA time-delay fuse is specified. Lower-voltage circuits simply present less stress to the fuse element.