Product Overview
Bel Fuse 5TT Series 3 Amp 250 Volt Time-Delay Miniature Cartridge Fuse
Condition
Unused new old stock (NOS). End caps stamped with 5TT series designation on one end and 3A 250V on the opposite end. Clean glass body with visible coiled internal element. Overall length measures 20 mm with a 5 mm outer diameter.
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Product Overview
The Bel Fuse 5TT 3-R is a 3-amp, 250-volt time-delay miniature cartridge fuse built to standard 5x20 mm dimensions. Designed with a coiled internal wire element inside a clear glass body, it provides controlled slow-blow performance to withstand brief inrush surges without nuisance opening. Nickel-plated brass end caps ensure reliable conductivity and corrosion resistance in standard fuse clips and panel-mount holders.
Key Features
- Current rating: 3 A
- Voltage rating: 250 V AC
- Characteristic: Time-delay (slow-blow) response
- Physical dimensions: 5 mm diameter by 20 mm length
- Body construction: Clear cylindrical glass body
- End caps: Nickel-plated brass contacts
- Internal element: Visible coiled wire filament for rapid visual inspection
- Interrupting rating: 100 A at 250 V AC
- Safety compliance: UL 248-14 compliant
Applications
- Replacing blown slow-blow fuses in audio amplifiers, linear power supplies, and test bench gear.
- Protecting equipment with inductive loads or transformer inputs prone to startup inrush current.
- Integrating overcurrent safety into custom power distribution boxes, maker projects, or vintage electronics restorations.
Frequently Asked Questions
What is the difference between a fast-acting fuse and this slow-blow fuse?
A slow-blow fuse features a time-delay coiled element designed to absorb short, temporary current spikes, such as transformer startup inrush, without opening. A fast-acting fuse opens almost instantaneously under the same overload condition.
Will this fuse fit standard 5x20 mm fuse holders and PCB clips?
Yes. The body measures 5 mm in diameter and 20 mm in length, which matches the standard international miniature fuse footprint used across consumer, commercial, and industrial equipment.
Why buy individual fuses here instead of a bulk multi-pack?
Most fuse assortments force you to buy dozens of values you will never use just to get the single 3A rating you need for a repair. We count out the exact quantity required for your project without forcing you into an oversized lot. More pieces cost less each, and the price-break table on this page shows what each quantity costs. Shipping is an $8 flat rate, free once your order passes $28, and orders leave our Idaho warehouse the same or next business day.
A slow-blow fuse is built with the patience to ignore a healthy inrush surge and the discipline to sacrifice itself when trouble is real. Pop it into the holder, close up the chassis, and let your circuit get back to work.
