For an arcing fault where the arc resistance is significant an impedance or admittance relay will
The reach of a reactance relay is unaffected due to the arc resistance while an impedance and admittance relay under reaches.
Kick fuses are used across relay coils to prevent relay operation during
There is a problem of high transient over voltages while interrupting
High transient over voltages occurs in power system due to formation of capacitance across the breaker poles. These are also called switching over voltages.
The most suitable circuit breaker for voltages above 220 kV is
Match List-I with List-ll and select the correct answer using the codes given below the lists:
A. Mho relay
B. Reactance relay
C. Simple impedance relay
1. Voltage restrained OC relay
2. Direction restrained OC relay
3. Voltage restrained directional relay
Pilot relaying schemes are used for protection of
Pilot relaying schemes provide high speed protection for transmission lines.
Relays A and B have to be coordinated on two adjacent line sections as shown in figure below. Zone-1 and Zone-2 settings are indicated on the diagram.
Which of the following indicates correct time setting for zone-2 of relays A and B?
Identify the relays to be provided with directional and non-directional elements in the system shown in figure below.
If the fault current is 2000 A, the.relay setting 50% and the CT ratio is 400/5, then the plug setting multiplier will be
Relay operating current,
The percent bias for a generator protection lies between