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What else can I help you with?
What is difference between the mcb and rcb?
MCB stands for miniature circuit breaker , which provides protection against over current. the setting is not adjustable. RCB stands for residual circuit breaker which provides protection against earth fault as well as over current. It monitors the current difference between phase and neutral and if the difference is more than rated value say 200 milli amps it will trip.
What is the breaking point in the layers of earth is called?
A break in the Earth's surface might be called a chasm, a fissure, or a fault line.
How long is the average fault?
There is really no "average" fault because all of the fault lines on the earth join together. There are names for different sections of the fault lines, most notably the one in the Pacific Ocean called the mid-Pacific oceanic ridge.
What are the faults?
There are 3 main types of faults 1. Normal 2. Strike slip 3. Reverse(Thrust) In a normal fault the foot wall stays in place while the hanging wall moves DOWNWARDS In a strike slip the tectonic plate(s) slide past each other horizontally In a reverse fault, the hanging wall gets pushed UPWARDS over the foot wall (The pictures are in the reverse order)
What is fault creep?
Fault creep is slow movement along a fault line with NO resulting earthquake.
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 the difference between balanced earth fault and restricted earth fault?
There is such a thing as a three phase to earth fault, so maybe this is what you mean by a "balanced earth fault". I don't believe any earth or ground currents would flow in this case. A restricted earth fault is a typical phase to earth fault, where the zone of protection is restricted to a specific area, such as around a transformer. "Restricted" is referring to the protection method, not what is actually going on with the currents and voltages.
Restricted earth fault protection circuit?
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).
Can earth fault current go up passing through the downstream panel and directly cause a trip at the upstream panel which have higher set point of earth fault protection?
If the fault is a direct short to ground, the fault current can be high enough to trip the upstream protection.
What can fuses not provide protection against?
Fuses do not provide protection against ground faults. Protection against a ground fault can be provided by breakers. If a fuse blows, it has to be replaced. If a breaker is tripped to off due to a surge in electrical current, the breaker can be reset.
Why is sensitive earth fault protection required?
Sensitive Earth Fault protection is required to either to alarm or trip the faulted circuit. It is usually used for resistance grounded or ungrounded systems; where first earth fault doesn't interrupt supply. It is also used on long overhead lines (even solidly grounded systems) where earth fault currents can be significantly low.
What is the minimum Earth fault current that an Earth leakage protection unit must be able to sense?
10mA
What is an Unrestricted Earth Fault?
I'm guessing this is in reference to a restricted earth fault, and you want to know what the opposite is? Restricted earth fault protection is designed to operate for earth faults within a specific zone. Unrestricted protection will operate for faults "anywhere", as long as the pickup can be satisfied. For example, REF (restricted earth fault) transformer protection looks for a small amount of neutral current, and if this exists, and the relay identifies this current as being within the zone of protection, the relay will trip. If it were unrestricted, the small amount of neutral current alone would be enough to cause a trip.
Why is there a ground wire?
The ground earth wire serves two purposes: To trip the protection as quickly as possible if theres an out of balanced current or a fault to earth. and to bring the user to the same potential to the earth if there is a fault and the protection doesnt trip. that way because you are at the same potential as earth you will not get electrocuted.
Calculation of restricted earth fault relay stabilizing resistor?
Requirement of REF protection for 50KVA 11KV/.4KV transforemr
Why fault protection is essential.?
To prevent overheating/damage/fire of the electrical components in a circuit.
How is restricted earth fault called so how is it restricted?
A Restricted Earth Fault (REF) refers to a method of fault protection that is applied to electrical system units, such as transformers or generators, that is more sensitive than the method known as Differential Protection (DP).An REF relay works by measuring the actual current flowing to earth from the frame of the unit. If that current exceeds a certain preset maximum value of milliamps (mA) then the relay will trip to cut off the power supply to the unit.REF protection is applied on transformers in order to detect ground faults on a given winding more sensitively than when only using differential protection.Differential Protection is commonly used to protect the windings of a transformer by comparing the current in the power supply's neutral wire with the current in the phase wire. If the currents are equal then the DP Relay will not operate. If there is a current imbalance then the DP Relay operates.REF and DP protection devices operate in similar ways to a GFCI or RCD device, which combines both REF and DP functions inside the one single device.For more information about GFCIs and RCDs, please see the answer to the Related Question shown below.
