What is branch circuit protection?
As a branch circuit protection device, UL 489 circuit breakers are tasked with protection of the circuit wiring. Their purpose is to help prevent electric shock and fire, and to provide a means for electrical isolation during maintenance periods.
What provides branch circuit protection and where is it located?
Fuses and circuit breakers are usually installed on motor circuits to protect the motor branch-circuit conductors, the motor control apparatus and the motors against overcurrent due to short circuits or ground faults.
What is a branch circuit overcurrent device?
100 as follows: “A branch circuit overcurrent device is a device capable of providing protection for service, feeder, and branch circuits and equipment over the full range of overcurrents between its rated current and its interrupting rating.
What is meant by overcurrent protection?
ANSWER: Overcurrent protection is protection against excessive currents or current beyond the acceptable current rating of equipment. It generally operates instantly. Short circuit is a type of overcurrent. Magnetic circuit breakers, fuses and overcurrent relays are commonly used to provide overcurrent protection.
Why is overcurrent protection required?
Overcurrent protective devices protect the circuit conductors in two ways. They protect the conductors from overload conditions and from short-circuit or ground-fault conditions. … If the circuit supplies equipment, such as a motor, and it becomes overloaded, the motor overload relays will open.
What is the purpose of circuit protection?
Why are circuit protective devices important? Protective devices are important because they ensure that under fault conditions, a high fault current cannot flow – as well as protecting the installation this, more importantly, ensures that consumers are not injured or killed as a result of an electrical fault.
Is a subpanel a branch circuit?
Subpanel Power Supply
Answer: In short, yes. The main electrical service panel is where branch circuits originate. … Individual branch circuits that only supply one utilization equipment, such as a central heating gas furnace, an electric clothes dryer, an electric range and so on.
How do you protect an overcurrent motor?
Overcurrent protection is generally accomplished by separating the overload protection from the short-circuit and ground-fault protection device. If you use fuses, you must provide one for each ungrounded conductor (430.36 and 430.55). Thus, a 3-phase motor requires three fuses.
What devices provide short-circuit protection?
The fuse is ideal for protection against short circuits. Short circuits produce enough amperage to vaporize a fuse element and break connection in one cycle of a 60-cycle system. Fuses are more commonly used in devices connected to a system than within the system’s circuit.