Search results
Results From The WOW.Com Content Network
Distance relays are actually double actuating quantity relays with one coil energized by voltage and other coil by current. The current element produces a positive or pick up torque while the voltage element produces a negative or reset torque. The relay operates only when the V/I ratio falls below a predetermined value (or set value). During a ...
If the relay setting is determined to be below the apparent impedance it is determined that the fault is within the zone of protection. When the transmission line length is too short, less than 10 miles, distance protection becomes more difficult to coordinate. In these instances the best choice of protection is current differential protection.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
In many cases, it is possible to design a relay logic diagram directly from the narrative description of a control event sequence. In general, the following suggestions apply to designing a relay logic diagram: 1. Define the process to be controlled. 2. Draw a sketch of the operation process. Make sure all the components of the system are ...
A broken rail or wire will break the circuit between the power supply and the relay, de-energizing the relay. See exception below. A failure in the power supply will de-energize the relay. A short across the rails or between adjacent track sections will de-energize the relay.
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).
In electrical systems, a static relay is a type of relay, an electrically operated switch, that has no moving parts. [1] Static relays are contrasted with electromechanical relays, which use moving parts to create a switching action. Both types of relay control electrical circuits through a switch that is open or closed depending upon an ...
The piping between the main tank and conservator is arranged so that any gas evolved in the main tank tends to flow upward toward the conservator and gas detector relay. [2] Schematic diagram of a large oil-filled power transformer. The conservator tank, green, at right, is marked 3 and the Buchholz relay is marked 5