0
To determine the value of Stabilizing resistor Rs = Vs/Is = If(Rct +2Rl)/Is Where, Rs = resistance value of the stabilizing resistor Vs = voltage at which the relay will operate Is = current flowing through the stabilizing resitor and the relay If = maximum secondary fault current magnitude Rct = internal resistance of the current transformer Rl = resistance of attached wire leads
What else can I help you with?
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).
How can you get negative voltage?
Your question should read "How do you get a negative potential?", for the reasons explained below.The term, 'voltage', is another word for 'potential difference'. The terms 'positive' and 'negative', when applied to a potential difference or voltage indicates the sense (or direction) in which the potential difference or voltage is acting. For example, if a second voltage is acting in the same direction as another voltage then it is acting in the positive sense; if it is acting in the opposite direction then in is acting in the negative sense'.It's very important to understand that you cannot apply 'positive' and 'negative' is the sense of charge or polarity to potential difference or voltage. You can, however, apply these terms to 'potential'. Potential is relative, and always measured with respect to a given point (often, the earth). So a point can be, for example, +5 V or -5 V with respect to another point (usually earth or ground, but not necessarily).Never confuse 'potential' with 'potential difference' and remember that 'voltage' means potential difference notpotential.So, to obtain a negative potential, earth (ground) the positive terminal of the battery or d.c. supply. All potentials measured relative to earth are now negative. To obtain a positive potential, earth the negative terminal of the battery or d.c. supply instead. All potentials measured relative to earth are now positive.If you want to get a negative potential,Earth the positive terminal of the DC power sourceConnect a resistor in series with the negative terminal of the sourceAt the other end of the resistor you get a negative potential (the value's less than the value of the power supply)
What is the difference between neutral earthing resistance and solid earth?
The star point of a primary*-transformer's secondary winding is frequently connected to earth via an impedance, in order to limit the return current in the event of an earth fault close to the transformer. The impedance may be a resistor or an inductor, (choke) depending on the nature of the earth return. In general, if the earth resistance is low, then resistive earthing is used; if the earth resistance is high, then inductive earthing is used.(*e.g. 33/11 kV)For resistive earthing, the transformer secondary's star point is often connected to the centre electrode of a galvanized-steel tank which is solidly earthed. The tank is then filled with water, and it is the resistance of the water that provides the required resistance to earth. The actual resistance of the water is modified to the desired value by dissolving sodium carbonate into the water while measuring its resistance. The solution has a negative temperature coefficient of resistance, which means that, in the event of an earth fault, as the fault current increases, the increasing temperature causes the resistance of the water to decrease, thus accelerating the response time of the protective system.
How you using ref relay in transformer?
an REF relay (restricted earth fault) is used to provide ground fault protection for a transformer. Its' operation is limited by CTs starred towards the transformer (usually on the transformer bushings or in breakers used to isolate the transformer), so it will only operate for transformer related faults. Because of this, it can be set to operate very quickly.
Calculation of restricted earth fault relay stabilizing resistor?
Requirement of REF protection for 50KVA 11KV/.4KV transforemr
What accounts for stabilizing effects of Earth's ocean?
The high latent heat of water.
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.
Why neatural ground resistor using in 33kv transformer?
The function of a neutral earth resistor is to limit any fault current resulting from fault between a line conductor and earth.
What is the earth's companion in space?
The Earth's companion in space is the Moon. It is the only natural satellite of the Earth and plays a crucial role in influencing ocean tides and stabilizing the Earth's rotation.
What actors and actresses appeared in Designing Middle-Earth - 2004?
The cast of Designing Middle-Earth - 2004 includes: Dan Hennah as himself Peter Jackson as himself
How does the moon affect planets?
the moon creats earths tides! It also effects the planet by stabilizing the rotation of earth!
What is the earth companion?
The Earth companion is commonly referred to as the Moon. It is Earth's only natural satellite and plays a significant role in various aspects of our planet, including tides and stabilizing our rotation.
What is the largest natural satellite orbiting the earth?
The only natural satellite orbiting Earth is the moon.
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.
Do tornadoes change the Earth's atmosphere?
The updraft of a tornado may help somewhat in stabilizing the atmopshere, but the parent thunderstorm normally would do that anyway.
Compound word for earth the meaning attached to the earth?
"Earthbound" can be used as a compound word to convey a sense of being connected to or restricted by the earth.
