Let’s first help with a few definitions (and differences):
- Disconnect: Think knife switch
- Switch: Think light switch like on the wall at home
- Breaker: Think of all those handles in your load center in the garage
The breaker used in an RV Pedestal is used as a disconnecting device AND an over current device. This comes in handy when upkeep needs to be done on the circuit or an overload is found. In the event of an overload an electromagnet turns the circuit breaker off automatically and the only thing you need to do to restore power (once the problem has been fixed) is to reset and turn the circuit breaker back on. By combining the two you have a cost-effective practical device.
The other option is a fused disconnect. The disconnect switch is a combination of a switch to disconnect the circuit and a fuse to shut the circuit off in the event of a problem. So why don’t we have the option to get either or? This is where the practicality of the breaker comes into play. The fused disconnect requires a fuse to restore power. Fuses are available in multiple sizes and ratings. Standard fuses can react quickly to over current situations, breaking the circuit almost immediately, while slow-burning fuses can handle high currents for short intervals, which can be useful to handle the in-rush current of motors when they first start.
Disconnects are typically used in high current applications and using a fuse for over current protection. Because they are used in high current applications, they are expensive as they need to carry higher currents, therefore beefier.
Even though circuit breakers and fused disconnects both serve the same general purpose, to open circuits in the occurrence of an overload or short circuit, breakers are still more cost effective and practical.
Back in the dark ages RV Pedestals had fuses. But like most things in life, especially in the electrical field, innovation found a more practical way to safeguard our pedestals (and ourselves). It’s interest to think about what the next great innovation to these pedestals might be… If you have a question for the Wizard of Watts please submitted here.