Fuses were once the only way to protect against short circuits, circuit overloads, and other faults. However, circuit breakers offer many advantages over fuses. For example, circuit breakers can help machine manufacturers and facility management teams achieve greater safety and reliability, lower costs, and support for energy management initiatives.
1. Consistent performance
Circuit breakers offer many advantages over fuses; including being tested during manufacture and able to be retested during their operating life to ensure performance is maintained. One downside of circuit breakers is that they cannot be tested beforehand to see the exact current value that will cause them to open, so there is always a small element of uncertainty. However, this is generally outweighed by the benefits circuit breakers provide.
2. Extended protection
Circuit breakers offer many advantages over fuses, including higher breaking capacity, faster trip time under overload conditions, and better fault current limitation. This not only supports reliable protection, it also reduces asset aging and extends service life. Another aspect of protection to keep in mind is that circuit breakers will always break all three phases simultaneously, whereas with fuses it is common for only one of three to open.
3. Enhanced safety and uptime
Fuses can be a safety hazard for those working with them. Because the wires are exposed, it can be dangerous for someone inexperienced to replace a fuse. With circuit breakers, the connections are hidden and the breaker can be operated remotely, making it a much safer option, particularly for those who are not trained in electrical work. One of the main causes of fires in industrial settings is due to a fuse being replaced with the wrong model or rating – something that would not happen with a circuit breaker. Additionally, replacing fuses takes more time than simply reclosing a breaker, meaning circuit breakers help to minimize downtime and production losses.
4. Cost savings
While the cost of a single fuse is cheaper than a circuit breaker, the overall cost of using fuses can be more expensive. This is because three fuses are required for a three-phase circuit, and each fuse needs a base. Additionally, fuses don’t have any built-in switching capability, so an upstream switch is necessary. Fuses also require a larger enclosure due to their heat dissipation. Finally, when one of three fuses open, all three need to be replaced. Thus, having an expensive replacement stock of fuses on hand is necessary. In comparison, occasional replacement of circuit breakers may be necessary, but a single model of breaker can be used for different power ratings—minimizing inventory.
5. Greater functionality
Fuses are cheaper than circuit breakers when purchased individually. However, total installation costs must be considered when making a decision about which to use. Factors such as the need for three fuses in a three-phase circuit and the lack of built-in switching capability in fuses, as well as the fact that they require a larger enclosure due to heat dissipation; can make the overall cost of using fuses greater than that of circuit breakers. Additionally, when one fuse opens, all three must be replaced, meaning that an expensive replacement stock of fuses must be kept on hand. In contrast, occasional replacement of circuit breakers may be necessary but a single model of breaker can usually suffice for different power ratings, minimizing inventory.