What is the purpose of the 52a contact?

What is the purpose of the 52a contact?

52a is a heavy-duty contact that is rated to interrupt that current so that the tripping devices (relays) do not have to. 3. Trip coil is not rated for continuous current. It needs to be de-energized as soon as possible after it has done its job to trip the breaker.

What is TCS relay?

Such Trip Circuit Supervision (TCS) relays are intended for a continuous supervision of circuit breaker trip circuit, and to give an alarm for loss of auxiliary supply, faults on the trip-coil or its wires independent of the breaker position, faults on the breaker auxiliary contacts and faults in the supervision relay …

What is lockout relay?

Lock out relay is an electromechanical relay which latches its output contact. As the name suggests, this relay once operated locks out the circuit. Locking out means that circuit cannot be normalized until and unless this relay is reset. These relay have two types of coils: operating and resetting coil.

What is 52a and 52b?

52a – AC circuit breaker position (contact open when circuit breaker open) 52b – AC circuit breaker position (contact closed when circuit breaker open)

What is shunt reinforcing unit?

2.1 Shunt Tripping Scheme. This is the most commonly used tripping scheme. The protective relay (PR) contact is arranged directly to trip the circuit breaker and it simultaneously energises an auxiliary unit X which then reinforces the contact that is energising the trip coil. The scheme is shown in Figure 1.

What is anti pumping relay?

The anti-pumping relay is a device in circuit-breaker whose function is to prevent multiple breaker closures. For instance, if the operator gives the closing command to the breaker by pressing the close button and the breaker closes. However, a fault in the system causes the breaker to trip.

What is TNC switch?

TNC switch is a three position switch , when it is in. close position it put the circuit breaker in operation by. energizing the closing coil and when it is in trip position. it will trip the circuit by energising the trip coil in circuit. The switch return to neutral position after any operation.

What is master relay?

What is a Master Trip Relay? Defination: Master trip relay is a contact multiplication or an Auxillary relay, which operates on the command from Multiple protection relays and gives a Single Commmand to the Breaker Trip Coil.

What is DC supervision relay?

This type of relay is used to supervise the DC supply. The relay coil terminals 1 & 2 are connected to the DC supply, which is to be monitored. In case, the DC auxiliary supply is available, the relay’s ‘NO’ contact closes and healthy status is indicated through ‘WHITE’ flag.

What is anti pumping relay in circuit breaker?

Anti Pumping Relay is used in a Circuit Breaker to indicate the spring failure of TNC i.e. Trip Neutral and Close (TNC) switch. TNC switch is used to manually Open and Close the Circuit Breaker either from Local or Remote.

What happens if the anti-pump function is removed from a circuit?

Without the anti-pump function, if the user connected a maintained contact in the close circuit, and the circuit breaker were closed into a fault current, the protective relays would cause an immediate trip action, but the maintained contact in the close circuit would initiate closing (again) into the fault.

What is the use of trip free mechanism / anti pumping?

Meanwhile a fault has taken place and fault sensing relay gives a trip command to the Circuit Breaker. The Trip Free Mechanism / Anti pumping feature ensures that the Circuit Breaker is tripped by protective relay even if it is under process of closing.

What is trip free mechanism in circuit breaker?

Meanwhile a fault has taken place and relay closes the trip circuit of breaker. The trip free mechanism/ Anti pumping feature permits the circuit breaker to be tripped by protective relay even if it is under process of closing.