Standard delivery
£8 ex VAT · free over £200UK parcel delivery is £8 ex VAT, or free on orders over £200 ex VAT.
Heavier items may be charged at a weight-based or pallet rate, shown at checkout.
MERSEN FUSE 250V 5ST 20 A 5X20 MI5ST25V20
Mersen B233451 20 A time delay glass cartridge fuse, 5 × 20 mm, rated at 250 V AC for industrial circuit protection.
Why Choose the Mersen B233451 20 A Time Delay Glass Cartridge Fuse?
The Mersen B233451 is a high quality 5 × 20 mm time delay glass cartridge fuse designed to provide dependable overcurrent protection for industrial electrical equipment, power supplies and control circuits. As part of the trusted Mersen 5ST IEC Miniature Fuse series, it offers reliable protection against overloads and short circuits whilst allowing temporary inrush currents during equipment start-up.
Its time delay (slow blow) characteristic enables the fuse to tolerate brief current surges without unnecessary operation, making it ideal for motors, transformers and equipment with high starting currents. The glass cartridge construction also allows for quick visual inspection of the fuse element during maintenance.
With a rated current of 20 A, a 250 V AC voltage rating and a standard 5 × 20 mm format, the B233451 is suitable for a wide range of industrial, commercial and OEM electrical applications requiring reliable circuit protection.
Key Advantages
- Reliable time delay miniature fuse for industrial electrical equipment.
- 20 A current rating for higher current applications.
- 250 V AC rated voltage for IEC electrical systems.
- Time delay characteristic prevents nuisance operation from inrush currents.
- Glass body enables quick visual inspection.
- Compact 5 × 20 mm format fits compatible fuse holders.
Key Features
- Mersen 5ST IEC Miniature Fuse series.
- 20 A rated current.
- 250 V AC rated voltage.
- Time delay (slow blow) operating characteristic.
- 5 × 20 mm glass cartridge construction.
- Designed for industrial circuit protection.
- Suitable for motor and transformer circuits.
- RoHS compliant.
Reliable Protection for Industrial Equipment
Time delay fuses are designed to withstand the temporary inrush currents generated when motors, transformers and power supplies are energised. They continue to provide dependable protection against sustained overloads and short circuits, helping reduce unnecessary downtime while safeguarding valuable equipment.
The Mersen B233451 combines reliable performance, a compact footprint and proven Mersen manufacturing quality, making it an excellent choice for OEM machinery, industrial control panels and electrical distribution equipment.
Typical Applications
- Industrial control panels.
- Motor control equipment.
- Transformers.
- Power supplies.
- OEM machinery.
- Electrical distribution equipment.
Technical Specifications
Tick the specs you need, then view products that match.
| Current | 20 A | |
|---|---|---|
| Voltage | 250 V | |
| Device Type | Fuse link | |
| Fuse Type | Miniature | |
| Fuse Size | 5x20 mm | |
| Fuse Class | Time delay | |
| Manufacturer | Mersen | |
| Series | 5ST IEC Miniature Fuses | |
| Model | B233451 | |
| Catalogue number | MI5ST25V20/100 | |
| Product type | Time delay glass cartridge fuse | |
| Current rating | 20 A | |
| Rated voltage | 250 V AC | |
| Fuse size | 5 × 20 mm | |
| Operating characteristic | Time delay (slow blow) | |
| Body material | Glass | |
| Application | Industrial electrical circuit protection | |
| Standards | IEC miniature fuse, RoHS compliant |
Frequently Asked Questions
What is the Mersen B233451 used for?
It is used to protect industrial electrical circuits, motors, transformers and power supplies against overloads and short circuits whilst allowing temporary inrush currents.
What is the current rating of this fuse?
The Mersen B233451 has a 20 A current rating.
Is this a fast acting fuse?
No. It is a time delay (slow blow) fuse designed to tolerate short-duration start-up currents.
What size is the fuse?
The fuse uses the standard 5 × 20 mm miniature cartridge format.
Where is this fuse commonly installed?
It is commonly installed in industrial control panels, power supplies, machinery, transformers and OEM electrical equipment.
Trusted for Industrial Circuit Protection
Mersen miniature fuses are trusted worldwide by panel builders, machine manufacturers and maintenance engineers for providing dependable protection in demanding industrial and commercial applications.
