Can I replace a glass fuse with a ceramic fuse of the same rating?

Yes, you can generally upgrade a glass fuse to a ceramic fuse as long as the physical size (5x20mm), amperage, voltage, and blowing characteristic (slow-blow) match exactly.

What is the difference between a slow-blow and a fast-acting fuse?

A slow-blow fuse is designed to withstand temporary high-current surges (like when a motor starts) without breaking, whereas a fast-acting fuse blows instantly upon detecting any overcurrent.

How do I know if my ceramic fuse has blown since I cannot see inside it?

Because the ceramic tube is opaque, you must use a digital multimeter set to the continuity or resistance (ohms) mode to test if the internal wire is broken.

Can I buy just one fuse instead of a pack of 10 at your Hong Kong store?

These fuses are pre-packaged and sold in cost-effective 10-piece sets at our Sun Cheong Computer Co. Ltd. store, ensuring you always have handy spares for future repairs.

Why does my device use a specific 3.15A rating instead of a standard 3A?

The 3.15A rating is a highly specific international standard used by engineers to provide precise thermal protection for sensitive power supply units, and you should not substitute it with a 3A or 4A fuse.

5x20mm Ceramic Slow-Blow Fuse 250V (10-Pack)

Name: 5x20mm Ceramic Slow-Blow Fuse 250V (10-Pack) | 1A-6.3A
Brand: Sun Cheong Computer Company Limited
SKU: 21PS000516-1A
Price: 10.0 HKD
Availability: InStock

Short Product Description

The 5x20mm Ceramic Slow-Blow Fuse (10-Pack) provides essential overcurrent protection for power supplies, motor circuits, and industrial electronics. Featuring a durable ceramic body and a 250V rating, these time-delay fuses withstand temporary power surges without nuisance tripping. Available in 1A, 2A, 3A, 3.15A, 5A, and 6.3A ratings. In stock at Sun Cheong Computer Co. Ltd. (新昌電腦有限公司) in Sham Shui Po, offering a quick and reliable repair solution for both DIY enthusiasts and professional technicians.

Key Features

Slow-Blow Characteristic: Tolerates harmless startup power surges to prevent nuisance tripping in motor and transformer circuits.
High Breaking Capacity: The solid ceramic body safely contains electrical arcs and prevents shattering during severe overcurrent events.
Universal 5x20mm Size: Standardized dimensions (5.2mm x 20mm) fit perfectly into most common PCB fuse holders and inline sockets.
250V Maximum Rating: Safely handles standard AC mains voltage, making it ideal for household appliances and industrial power supplies.
Convenient 10-Piece Pack: Provides ample spares for ongoing maintenance, ensuring you always have a replacement ready when needed.

Full Product Description

Reliable Time-Delay Protection

These slow-blow ceramic fuses are specifically engineered to tolerate temporary inrush currents without breaking the circuit. Unlike fast-acting glass fuses, this time-delay design is perfect for devices that require a brief surge of power during startup, such as electric motors, transformers, and heavy-duty power adapters. By absorbing these harmless spikes, the fuse prevents frustrating false trips while still offering robust protection against genuine short circuits.

Durable Ceramic Construction

The opaque ceramic tube design offers superior thermal and physical stability compared to standard glass fuses. When a severe short circuit occurs, the ceramic body safely contains the internal arc and prevents the fuse from shattering. This high breaking capacity ensures maximum safety for your expensive electronic equipment and the surrounding circuitry.

Pro Tip from Our Technicians

Always replace a blown fuse with one of the exact same amperage and blowing characteristic (slow-blow vs. fast-acting). Our Sham Shui Po repair specialists warn that substituting a slow-blow fuse with a fast-acting one will result in immediate blowing upon device startup. If you are unsure about your device's requirements, bring your blown fuse to our store, and we will help you identify the correct replacement.

Technical Specifications

Product Type: Ceramic Cartridge Fuse
Blowing Characteristic: Slow-Blow / Time-Delay (T)
Voltage Rating: 250V AC
Available Current Ratings: 1A, 2A, 3A, 3.15A, 5A, 6.3A
Dimensions: 5.2mm (Diameter) x 20mm (Length)
Material: Ceramic Tube with Nickel-Plated Brass End Caps
Package Quantity: 10 Pieces per pack

Delivery Options

Local delivery within Hong Kong and in-store pickup.
Free shipping for orders of HK$400 or above; HK$35 shipping fee for orders below HK$400.
Shipped by SF Express, usually dispatched the same day for orders confirmed before 6:00 PM (Mon–Sat).
Estimated delivery time: 1–3 business days after dispatch (Hong Kong).
In-store pickup details (location and time) will be confirmed by email or phone message.
Delivery times are estimates and may be affected by weather or unforeseen circumstances.

FAQ Section

Can I replace a glass fuse with a ceramic fuse of the same rating?Yes, you can generally upgrade a glass fuse to a ceramic fuse as long as the physical size (5x20mm), amperage, voltage, and blowing characteristic (slow-blow) match exactly.
What is the difference between a slow-blow and a fast-acting fuse?A slow-blow fuse is designed to withstand temporary high-current surges (like when a motor starts) without breaking, whereas a fast-acting fuse blows instantly upon detecting any overcurrent.
How do I know if my ceramic fuse has blown since I cannot see inside it?Because the ceramic tube is opaque, you must use a digital multimeter set to the continuity or resistance (ohms) mode to test if the internal wire is broken.
Can I buy just one fuse instead of a pack of 10 at your Hong Kong store?These fuses are pre-packaged and sold in cost-effective 10-piece sets at our Sun Cheong Computer Co. Ltd. store, ensuring you always have handy spares for future repairs.
Why does my device use a specific 3.15A rating instead of a standard 3A?The 3.15A rating is a highly specific international standard used by engineers to provide precise thermal protection for sensitive power supply units, and you should not substitute it with a 3A or 4A fuse.

Target Users / Applications

Audio amplifier repair technicians needing time-delay protection for large toroidal transformers.
Industrial maintenance staff replacing fuses in 250V motor control circuits.
DIY electronics hobbyists repairing blown power supply units (PSUs).

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5x20mm Ceramic Slow-Blow Fuse 250V (10-Pack) | 1A to 6.3A