Q what is idmt relay

An IDMT relay is used to protect feeder through 500/1 CT. The relay has a PSM 100[ PSM 2 3 5 8 10 12; Time sec 10 6 4.5 3.2 3 2.5; ]If the fault current is 5000 A, then time of operation of relay will besec. JEE Main 2022 Question Paper Live Discussion. JEE Main 2022 Question Papers.

1. What is the IDMT relay?
2. What is IDMT and DMT relay?
3. Why IDMT relays are better?
4. What are the three types of IDMT relays?
5. What is minimum time in IDMT relay?
6. Which curve does IDMT relay follow?
7. What is DMT relay?
8. What does DMT relay stand for?
9. What is the disadvantage of IDMT relay?
10. What is the function of relay?
11. What is the best use of a relay?
12. What is T1 and T2 in relay?
13. What are the two main types of timing relays?
14. What is an IDMT curve?
15. What is the difference between L1 L2 L3 and T1 T2 T3?
16. Is L1 hot and L2 neutral?
17. What is L1 and L2 in a relay?

What is the IDMT relay?

IDMT relay is inverse definite minimum time relay. It is one in which Time of operation is inversely proportional to magnitude of fault current near pickup value and becomes substantially constant slightly above the pickup value of the Relay.

What is IDMT and DMT relay?

DMT and IDMT application is used so that when current raises above threshold value the relay does not trip immediately and the trip time is calculated for that actual current and still increasing for particular duration the relay signal is given manually and tripping occurs for protection of component.

Why IDMT relays are better?

Protective relays, especially IDMT (Inverse Definite Minimum Time) overcurrent relays is crucial in the power system protection. It is important that in any case of the system abnormalities or faults, the IDMT overcurrent must be capable to isolate only the faulty component from the healthy system.

What are the three types of IDMT relays?

Instantaneous overcurrent relay. Inverse time overcurrent relay. Inverse definite minimum time (IDMT) overcurrent relay.

What is minimum time in IDMT relay?

IDMT (inverse definite minimum time ) relay: In IDMT relay the operating time is approximately inversely proportional to the fault current near the pickup value and becomes substantially constant slightly above the pickup value of relay.

Which curve does IDMT relay follow?

The 'EI' type IDMT relay curve operates at very fast at high short-circuit currents and very slow at low short-circuit currents. This type of IDMT curve is most suited for coordination with fuses. Ideally, the same type should be used throughout the system.

What is DMT relay?

The Protection Relay block implements a protection relay for the hardware and the motor with definite minimum time (DMT) trip characteristics using the reference limit, feedback, and reset input signals.

What does DMT relay stand for?

DMT (Definite Mean Time) Relay – It operates when current in the circuit exceeds a set value & exceeded value of current remains in the circuit for a period/duration set in the relay. Instantaneous relay – It operates instantaneously/immediately when current in the circuit exceeds the set value/pick up of the relay.

What is the disadvantage of IDMT relay?

The use of IDMT overcurrent relay has some disadvantages. Most of the problems relate to the coordination between the main and the backup relay. One of the problems faced by the overcurrent relay is fault severity variation.

What is the function of relay?

1. The relay permits a small amount of electrical current to control high current loads. When voltage is supplied to the coil, small current passes through the coil, resulting in a larger amount of current passing through the contacts to control the electrical load.

What is the best use of a relay?

Relays are normally used in the control panels, manufacturing, and building automation to control the power along with switching the smaller current values in a control circuit.

What is T1 and T2 in relay?

Terminals T1 and T2 are a thermally activated contact on the resistor to indicate an overheat condition of the resistor. The contacts are normally closed and open once the braking resistor temperature reaches 120 degrees Centigrade. The minimum voltage/current for these contacts is 24VDC at .

What are the two main types of timing relays?

ON-delay timers and OFF-delay timers are two common types of time delay relays and solid state timers.

What is an IDMT curve?

Inverse Definite Minimum Time (IDMT) curves are used in both mechanical and electronic protection devices. These curves define the amount of time which should pass at a given current, before initiating an action, usually the tripping of a circuit breaker.

What is the difference between L1 L2 L3 and T1 T2 T3?

The L1, L2, and L3 terminals are where the power wires connect to the contactor. The T1, T2, and T3 terminals are where the device wires connect to the contactor. The L1 contact connects to the T1 contact, the L2 contact connects to the T2 contact, and the L3 contact connects to the T3 contact.

Is L1 hot and L2 neutral?

L1 and L2 are the wires which go to and from the power source. L1 is the hot wire. It carries 120V to the components. L2 is the neutral wire.

What is L1 and L2 in a relay?

1. The two vertical lines that connect all devices on the relay logic diagram are labeled L1 and L2. The space between L1 and L2 represents the voltage of the control circuit. 2. Output devices are always connected to L2.