What is non selective coordination?
A fault on a branch circuit opens protective devices “D”, “C” and “B.” The entire power supply to the building is completely shut off. This non-selective operation is normally the result of a medium to high level short circuit. This fault may be line-to-line, line-to-ground, or 3 phase bolted in nature.
What is selective coordination NEC?
Although the definition has changed slightly over the years, NEC 2014—the most recent version of the code—defines selective coordination as: “Localization of an overcurrent condition to restrict outages to the circuit or equipment affected, accomplished by the selection and installation of overcurrent protective …
How do you do selective coordination?
These strategies enable overcurrent protection devices nearest to faults to trip first, avoiding power disruption to a greater amount of load equipment. Selective coordination is accomplished by using overcurrent protection devices with longer trip times near the power source and shorter times near load equipment.
What is selective coordination study?
Selective coordination generally describes the design of an electrical system in which the upstream protective device (fuse or circuit breaker) nearest to the system fault clears the fault without affecting the protective devices that are upstream from it.
What is circuit breaker coordination?
Breaker coordination refers to the use of breakers specifically—including the latest electronic trip breakers—to isolate electrical problems, stop nuisance tripping and avoid system-wide blackouts.
What is the difference between overload protection and fuse or circuit protection?
Short circuit is a type of overcurrent. Magnetic circuit breakers, fuses and overcurrent relays are commonly used to provide overcurrent protection. Overload protection is a protection against a running overcurrent that would cause overheating of the protected equipment. Hence, an overload is also type of overcurrent.
What is selective tripping?
Selective Tripping means that when a fault occurs anywhere in the distribution system, one and only one breaker will trip. That breaker will always be located upstream and closest to the fault. Simulate Circuit Breaker Tripping.
What is breaker coordination?
What is Type coordination?
Type 2 coordination is nothing but an immediate start without any work on the motor on starter under short circuit condition. It is applicable for both moving and fixed contacts. During this, the starter equipment such as contactor, relays, MCCB or MPCB (Not Fuses), Cable, bolts should not get any damage.
What is electrical system coordination?
Selective coordination is an electrical system design practice that improves reliability. Breaker coordination refers to the use of breakers specifically—including the latest electronic trip breakers—to isolate electrical problems, stop nuisance tripping and avoid system-wide blackouts.
Is overcurrent and short-circuit the same?
What is the difference between MCCB and Mpcb?
MPCB is specially designed for motor protection while in MCCB are specially designed for general-purpose circuit protection. MPCB can protect the motor against overload, short circuit, phase loss, and under-voltage faults while in MCCB can protect the motor against overload and short circuits.