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What is the difference between Ohms and Ohms CT in impedance of an audio transformer?
The difference in between Ohms and Ohms CT is that in Ohms CT it has CT at the end.
What is mean by burden of the current transformers?
The burden on a CT is the sum total impedance connected to the secondary - including the CT secondary winding coil resistance, lead resistance, and any loads attached (relays, meters, etc.).If this is for power calculations and CT saturation in three phase systems, remember you must multiply the lead resistance by two to get the total path resistance.Another AnswerWe use the word, 'burden', to describe the load supplied by the instrument transformer's secondary. This is normally a measuring instrument or protection relay. We use the word 'burden' to distinguish it from the 'load' supplied by the circuit to which the primary winding is connected.
Is it ok to have the dot on a current transformer upside down?
You are probably referring to a 'polarity mark'. This is very important if the CT's burden requires current to flow through it in a particular direction in order to work properly. For example, it won't make any difference if the burden's an ammeter. But if the burden is, say, a wattmeter, then it's very important to observe the CT's polarity mark when it is wired, otherwise the wattmeter might read 'downscale' (backwards). It's also very important when the CT supplies protection relays.
Why metrosil is provided in differential protection?
under internal fault conditions , CT primary current produces steep insrease in voltage across the relay. This will exceed the burden 3kv normally designed as per. To get protected from the voltage, metrosil is connected across the relay , to drop the voltage.
How do you calculate burden resistor fo current transformer?
The method I have seen employed is to estimate the maximum current that will flow in the secondary side of the CT due to fault currents on the primary side, and calculate the total load (resistance) on the secondary side, including the CT resistance, cable resistance (2 way for ground faults, 1 way for three phase and L-L), resistance of any meters/relays connected to the CT. Once this is known, the voltage rise in the CT can be determined to see if the CT is likely to saturate.Alternately, you can determine the VA burden by the above, VA = V*I = (I*R)*I, using Ohm's law.The above answers the question of how to calculate the VA burdon on a current transformer. The VA burden of a CT is determined by the resistivity of the CT, multiplied by the current squared through the secondary. In general, this will be provided by the manufacturer in the form of a CT burden characteristic, developed through testing of the CT in question, not through calculations.
What difference value between K and Ct?
the same as the difference between ct and k
What is the difference between Ohms and Ohms CT in impedance of an audio transformer?
The difference in between Ohms and Ohms CT is that in Ohms CT it has CT at the end.
What is CT operated electronic relay?
CT (Current Transformer ) is essential whether is electronic relay or electromagnetic relay. A relay requires the CT to sense the line current.
What is mean by burden of the current transformers?
The burden on a CT is the sum total impedance connected to the secondary - including the CT secondary winding coil resistance, lead resistance, and any loads attached (relays, meters, etc.).If this is for power calculations and CT saturation in three phase systems, remember you must multiply the lead resistance by two to get the total path resistance.Another AnswerWe use the word, 'burden', to describe the load supplied by the instrument transformer's secondary. This is normally a measuring instrument or protection relay. We use the word 'burden' to distinguish it from the 'load' supplied by the circuit to which the primary winding is connected.
What is the time difference between IST and CT?
There is no time difference between Central European Time and Irish Summer Time.
What is a ct of burden?
This is not understandable. Please rephrase and resubmit. Be specific
What is the difference between 22ct gold and 14ct gold?
The difference between 22 ct gold and 14 ct gold is that 22ct gold is 91.6 percent gold. 14 ct gold has 58.3 percent gold. The higher the number, the more pure gold is.
Is it ok to have the dot on a current transformer upside down?
You are probably referring to a 'polarity mark'. This is very important if the CT's burden requires current to flow through it in a particular direction in order to work properly. For example, it won't make any difference if the burden's an ammeter. But if the burden is, say, a wattmeter, then it's very important to observe the CT's polarity mark when it is wired, otherwise the wattmeter might read 'downscale' (backwards). It's also very important when the CT supplies protection relays.
What is difference between high impedance busbar protection scheme and low impedance busbar protection scheme?
high impedance circit provides a varistor unit which has stabilising resistor which ll protect the relay from being operating for maloperations like through fault, CT faults whereas this varistor unit is provided internally in an numerical relay where the CT of class 5P can be used.
What is difference between isolation transformer and earth protection relay?
An isolation transformer is a mutual transformer having a voltage ratio of 1:1, so that the secondary circuit is electrically isolated from the primary circuit, yet subject to the same voltage.An earth protection relay is a category of protective relay that responds to an earth fault monitored by a current transformer (CT). In the event of an earth fault being detected by the CT, the relay with activate the trip circuit to a circuit breaker which will then disconnect the fault.
Why metrosil is provided in differential protection?
under internal fault conditions , CT primary current produces steep insrease in voltage across the relay. This will exceed the burden 3kv normally designed as per. To get protected from the voltage, metrosil is connected across the relay , to drop the voltage.
What is a c200 current transformer?
This is a class of current transformers, and is a fairly low class. This has to do with what kind of burden can be placed on the secondary. A general rule is a C200 current transformer can supply ~200 volts at full ratio to its' secondary. If the burden (the CT resistance + cable resistance + relay or instrument resistance) times the maximum expected current is higher than 200 volts, the CT is likely to saturate. During multiple fault events, a CT may keep some magnetizing current causing CT saturation to be higher on a reclose event. Typically CT's are sized and their ratios are chosen to minimize saturation when feasible.
