0
What else can I help you with?
What are current relays?
Current relays are the relay which sens the current passing in particular circuit and operates when this current exceed its set value.
What is the difference between reverse current and overcurrent protection?
A reverse current relay senses Power in (uses both voltage and current, and looks at the phase angle between these), and operates if power is flowing in the reverse direction, and the current is above a set point. An overcurrent relay looks at only current, and operates if it is above a set point regardless of power flow direction. Reverse current relays are often referred to as reverse power relays.
How does the standby earth fault scheme work?
Restricted earth fault protection is used to protect a specific zone, and should not trip for a fault outside of that zone (usually limited to a transformer, and possibly extending to lowside, highside, and tertiary breakers). Stand by earth fault protection is a term I am not very familiar with, but I believe this would be protection that is meant for a specific zone as backup, and can operate for faults outside of this zone. An example might be a highside time overcurrent relay set looking into a transformer, where the transformer is protected by a differential (primary protection), and there is a lowside feeder with relays (primary protection). The highside overcurrent acts as a backup (secondary protection) for the transformer and the feeder, and is delayed due to the nature of a time overcurrent relay.
What are numerical relays?
As we know numerical relays use DIGITAL SIGNAL PROCESSOR as its computational hardware and based on microprocessor. WORKING: Analog input is feed into the anti aliasing filter which is a low pass filter.Output of this filter is feed into the sample and hold circuit , frequency of sampling should be twice of our highest frequency of interest(according to the nyquist criterion).if sampling frequency kept low than aliasing input may occur. after the sampling, signal are feed into the multiplexer,where all the signal get multiplexed and we have a single signal.this signal is feed into the analog to digital converter.this digital signal is feed into the microprocessor and microprocessor generates control signal according to its input. for example if you are using N.R. for over-current protection than you should set a value of current in your program.if the value of current passes through the circuit is greater than the set value..than N.R. enables the circuit breaker and hence our system is protected..
How do you calculate setting for over current earth fault relay setting?
An artificial neutral is crated in the CT of the line to be protected (for transmission lines) a CT is fixed in the neutral of the CT. if there is any imbalance in the 3 phase current then the relay will develop a difference in neutral.that can be sensed by the CT,then gives the trip command to relay
What is the difference between voltage restrained overcurrent protection and voltage controlled overcurrent protection?
Voltage restrained overcurrent protection uses a fixed voltage threshold to trip the protection device when an overcurrent condition is detected. In contrast, voltage controlled overcurrent protection adjusts the trip threshold based on the system voltage level, allowing for more precise coordination with other protective devices and better protection of the equipment. The key distinction lies in the method of setting the trip threshold: fixed voltage for voltage restrained, and voltage-dependent for voltage controlled overcurrent protection.
What are current relays?
Current relays are the relay which sens the current passing in particular circuit and operates when this current exceed its set value.
What is the difference between reverse current and overcurrent protection?
A reverse current relay senses Power in (uses both voltage and current, and looks at the phase angle between these), and operates if power is flowing in the reverse direction, and the current is above a set point. An overcurrent relay looks at only current, and operates if it is above a set point regardless of power flow direction. Reverse current relays are often referred to as reverse power relays.
How does the standby earth fault scheme work?
Restricted earth fault protection is used to protect a specific zone, and should not trip for a fault outside of that zone (usually limited to a transformer, and possibly extending to lowside, highside, and tertiary breakers). Stand by earth fault protection is a term I am not very familiar with, but I believe this would be protection that is meant for a specific zone as backup, and can operate for faults outside of this zone. An example might be a highside time overcurrent relay set looking into a transformer, where the transformer is protected by a differential (primary protection), and there is a lowside feeder with relays (primary protection). The highside overcurrent acts as a backup (secondary protection) for the transformer and the feeder, and is delayed due to the nature of a time overcurrent relay.
What is hinky pinky for a triple set of electrical contactors?
That would be: Three-phase relays
What does instantaneous speed include?
Instantaneous speed is your speed in a given moment. The speedometer in your car and the radar gun that cops use both give a value in instantaneous speed. The disctinction here is to not confuse instantaneous speed with average speed, which is calculated over a set distance. To calculate average speed (V) you need to divide the distance travelled (D) by the time of travel (T). V= D/T
What does instantaneous speed?
Instantaneous speed is your speed in a given moment. The speedometer in your car and the radar gun that cops use both give a value in instantaneous speed. The disctinction here is to not confuse instantaneous speed with average speed, which is calculated over a set distance. To calculate average speed (V) you need to divide the distance travelled (D) by the time of travel (T). V= D/T
What should the instantaneous trip be set at for a 100 amp breaker?
The instantaneous trip setting for a 100 amp breaker should be set around 500-1000 amps to allow for momentary inrush currents without tripping the breaker. It's important to refer to the manufacturer's specifications for the specific breaker model to determine the appropriate setting.
What does the constant control relay module do on 1999 Ford Escort?
The CCRM is a set of relays in the same box. The relays control the radiator cooling fan, the PCM, the fuel pump and the A/C compressor. Pre-97 Escorts had separate relays on the above functions. Starting in 97 continuing through 2002 they put all the relays in one box.
What is pick up of a relay?
The "pick up" of a relay is a setting at which the relay will begin to operate. Such as an overcurrent relay - if the pickup is set to 5A, when 5A is flowing through the relay, the relay will operate.
Why did Zen Buddhism appeal to Samurai Warriors?
Zen training in the instantaneous appreciation of a situation and the concurrent and equally instantaneous initiation of a response is the essence of the warrior skills. As a backup to this skill set the philosophy that actions are neither good or bad, but that they just "are" removed the expectation of remorse.
What does the constant control relay module do?
The CCRM is a set of 4 relays in one module. The relays are : 1. Relay for the PCM (Powertrain Control Module) 2. Relays for the high and low radiator fan speeds. 3. Relay for the fuel pump. 4. Relay for the Air Conditioning clutch on the compressor.
