Phoenix Contact Miniature Circuit Breakers
Phoenix Contact miniature circuit breakers are designed to protect devices from overload and short circuit situations. Device circuit breakers selectively shut down the faulty circuit while all other system parts remain in operation. There are three different types of device circuit breakers. They are: electronic, thermomagnetic and thermal device circuit breakers. The difference lies in their tripping techniques and behavior.
Electronic device circuit breakers trip within a few milliseconds, the shortest possible time. Thermomagnetic device circuit breakers have a tripping time that depends on the type of overload, and thermal device circuit breakers trip more quickly as the overload increases.
Device circuit breakers are used in assembly machines and production systems, in order to selectively protect the most varied of loads from short circuit and overload situations. Not every circuit breaker is suited to all applications. In order to select the right device circuit breaker for an application, the starting current and the nominal current of the load must be taken into account.
More Information about Phoenix Contact Miniature Circuit Breakers
Electronic device circuit breakers are ideal for protecting PLCs, sensors, actuators, motors, valves and relays. Thermomagnetic device circuit breakers are ideal for protecting PLCs, frequency inverters, motors and valves. Thermal device circuit breakers provide protection for inductive loads against overload in power distribution systems, manufacturing systems and control cabinet engineering.
FAQs
Do Phoenix Contact miniature circuit breakers require a separate power supply?
These circuit breakers do not require a separate power supply to operate. Instead, they are installed into the circuit they are protecting.
Trip Curve Basics Part 1
There are two critical elements in miniature circuit beakers.
Bimetal strip
This strip has two dissimilar metals attached to one another. When a prolonged overcurrent occurs, these metals begin to bend. Because the metals are different, the rate at which they bend is different, therefore causing the strip to bend. If this bending occurs long enough, the bending strip will disrupt the electrical contacts inside the breaker, causing it to trip.
Coil or solenoid
The coil or solenoid is designed for larger overcurrent events like a short circuit or lightning strike. When a large overcurrent event occurs, the plunger in the solenoid is actuated, thereby tripping the breaker.
What is a trip curve?
It is both the prolonged overcurrent protection from the bimetal strip and the higher spikes in voltage and current protection from the solenoid that make up the circuit breakers trip curve. How fast or slow these events occur determines the shape of the curve. A trip curve is simply a graphical representation of the expected behavior of a circuit protection device, in this case, a circuit breaker.
This graphical representation looks at two separate pieces of data to provide the information needed to understand when a particular breaker will trip. The first is time, more specifically, the time the circuit breaker experiences a certain amount of overcurrent. The second is the amount of current. In this case, how much more current is passing through the breaker than the protection device is actually rated for.