What are medium voltage fuses?
Technically speaking, medium voltage fuses are those intended for the voltage range from 2,400 to 38,000 Vac. High voltage fuses are for circuits carrying voltages greater than 38,000 Vac. E-rated fuses are considered to be general purpose fuses and can be used to protect against low and high values of fault current.
Which fuse is used in transformer?
ABB WBP Transformer Fuses – Fuse Ratings & Dimensions
| Catalogue Number | Fuse Name | Rated Voltage U (kV) |
|---|---|---|
| 1YMB750747M2201 | WBP-6 | 7.2 |
| 1YMB751206M2201 | WBP-10 | 12 |
| 1YMB752405M3201 | WBP-20 | 24 |
| 1YMB753604M3201 | WBP-30 | 36 |
How do you choose a fuse for a transformer?
In lieu of transformer inrush data, the rule of thumb is to select a fuse size rated at 300% of the primary full-load current and round up to the next larger standard size.
Why does a transformer need a fuse?
The sole purpose of a fuse is to blow in cases of short circuits (or when current exceeds the fuse rating). That said, fuses are used in a potential transformer circuit (Primary as well as Secondary) to protect from the PT’s winding faults and secondary circuit faults respectively.
What are standard fuse sizes?
Standard sizes for fuses and fixed trip circuit breakers, per 240.6, are 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450, 500, 600, 700, 800, 1000, 1200, 1600, 2000, 2500, 3000, 4000 5000, and 6000 amps.
Do all transformers have fuses?
All transformers are connected to the common secondary circuit through secondary fuses. The purpose of these fuses is to disconnect a faulty transformer from the secondary circuit.
How do you know what size fuse to use?
A fuse should be de-rated by 25% at room temperature, meaning if there is a 7.5 amp circuit, a 10 amp fuse should be used at 25˚C. Voltage ratings on a fuse can be higher than the voltage on the circuit, but not lower. At the end of the day, a simple fuse is a great way to effectively protect a circuit.
