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Low voltage and low current signals (i.e., at the secondary of a voltage transformers and current transformers) are brought into a low pass filter that removes frequency content above about 1/3 of the sampling frequency (a relay A/D converter needs to sample faster than twice per cycle of the highest frequency that it is to monitor).
Differential protection can be used to provide protection for zones with multiple terminals [49] [50] and can be used to protect lines, [51] generators, motors, transformers, and other electrical plant. Current transformers in a differential scheme must be chosen to have near-identical response to high overcurrents.
An isolation transformer provides maximum protection when the device is ungrounded. Connecting it to test equipment, for example, an oscilloscope or a benchtop multimeter, may ground the circuit. Electrical isolation is considered to be particularly important on medical equipment, and special standards apply.
In electrical engineering, a transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits.A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force (EMF) across any other coils wound around the same core.
A transformer is the most widespread example of galvanic isolation. ... acoustic, or mechanical coupling. ... for safety and equipment protection. For example, power ...
A Buchholz Relay is installed in the transformer oil circuit, and should the relay detect 'gassing' of the oil, will trip out the trains main circuit breaker, so isolating the equipment from the supply and therefore protecting the equipment from overheating or short circuiting. Once tripped, the equipment can only be reset by maintenance staff.
A high-voltage current transformer may contain several cores, each with a secondary winding, for different purposes (such as metering circuits, control, or protection). [7] A neutral current transformer is used as earth fault protection to measure any fault current flowing through the neutral line from the wye neutral point of a transformer.
The primary North American document that deals with outdoor high-voltage transformer fire barriers is NFPA 850. [1] NFPA 850 outlines that outdoor oil-insulated transformers should be separated from adjacent structures and from each other by firewalls, spatial separation, or other approved means for the purpose of limiting the damage and potential spread of fire from a transformer failure.