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Instantaneous over current relay, which operates very fast with no intentional time delay and the operating time of these relay can be as low as 0.01sec . These relay operates only when the impedance between the relay and the source zsis very small compared to the impedance to the impedance of the protected section zl .
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What is DTOC relay?
A definite time over-current relay operates like an instantaneous over-current relay coupled with a timer. Once current reaches the pick-up value, it initiates the timing circuit. As long as current stays above this pick-up value, the timer will continue to time. Once the definite time setting is reached, the relay gives trip signal to the circuit breaker.
What is the difference between an earth fault relay and an over current relay?
earth fault relay is also a type of over current relay but the set value of current or relay sensing current is much less than the maximum load current.in over current relay relay sensing current ise than maximum load current mor
Solving problems on instantaneous voltage and current?
yes
Earth fault relay and an overcurrent relay Methods to energise an earth fault relay?
Earth fault relay and an over current relay Methods to energies an earth fault relay with simulation diagram?
How can instantaneous current values be determined?
Voltage divided by the resistance of what ever you want to measure the current in.
What is DTOC relay?
A definite time over-current relay operates like an instantaneous over-current relay coupled with a timer. Once current reaches the pick-up value, it initiates the timing circuit. As long as current stays above this pick-up value, the timer will continue to time. Once the definite time setting is reached, the relay gives trip signal to the circuit breaker.
What is the difference between an earth fault relay and an over current relay?
earth fault relay is also a type of over current relay but the set value of current or relay sensing current is much less than the maximum load current.in over current relay relay sensing current ise than maximum load current mor
What sort of fuse would you select for an installation that required high current interrupting ability and an allowance for instantaneous over currents?
The best type fuse for an installation that required high current interrupting ability and an allowance for instantaneous over currents, would be the largest fuse sufficient for normal use and a relay to another fuse for the over currents. It is always best to consult an electrician.
How does time inverse over current relay work?
Over Current (Inverse Time) Over current relay function monitors the general balanced overloading and has current/time settings. This is determined by the overall protective discrimination scheme. There advantage over definite time relays is that they can have much shorter tripping times can be obtained without any risk to the protection selection process. These are classified in accordance with there characteristic curves, this indicates the speed of the operation. Based on this they are defined as being inverse, very inverse or extremely inverse. The typical settings for these relays are 0.7-2In (normal or rated generator current) in 1-10 second. Inducing a calibrated test current through the normal load current tests this relay.
What the three types of over current protection relay and describe the principles of operation?
over current protection relay
Is a current relay same as potential relay?
current relay are using for over current low state & high state.but potential relay are related to voltage.
How does an over current relay work?
An over current relay will operate when current exceeds its design rating. This application is intended protect loads or circuits from excessive current.
What is instantaneous power mean?
The product of the instantaneous voltage and the instantaneous current for a circuit or component.
Over current relay?
in electrical circuit current will increase specific level (full load current).its call over current
What is powerful mean?
The product of the instantaneous voltage and the instantaneous current for a circuit or component.
What is ocr efr uvr referred to in air blast circuit breaker?
ocr-over current relay(senses the over current in the circuits) efr-earth fault relay uvr-under voltage relay
What is the theory behind a definite time overcurrent relay?
A definite time overcurrent relay operates like an instantaneous overcurrent relay coupled with a timer. once current reaches the pickup value, the relay overcurrent relay will trip, which initiates the timing circuit. as long as current stays above this pickup value, the timer will continue to time. Once the definite time setting is reached, the timer will close the relay tripping contacts.
