IEEE 1610-2016 pdf free
IEEE 1610-2016 pdf free.IEEE Guide for the Application of Faulted Circuit Indicators on Distribution Circuits.
Underground and overhead FCIs are applied to monitor conductors at switchgear. transformers, junctions. cable dips, risers, etc. FCIs are attached to conductors, or test points, to sense for abnormally high currents typically associated with faults. FCIs trip with a visual, audible, radio, or remote indication when they have sensed conditions that are determined to indicate an overcurrent has passed its location. FCIs located along the fault current path will trip to indicate a “FAULT.” while those that do not determine a fault current has passed its location will remain “NORMAL.” Operating personnel locate the faulted section between the last FCI displaying “FAULT’ and the first FCI displaying “NORMAL.”
Circuits can be radial or looped. Looped circuits typically have an open point. When choosing the placement of FCls, consideration between cost and customer reliability should be made. FCIs could be placed on both the incoming and outgoing cables of each transformer. This would provide the most knowledge on where the fault is located since information would be available to differentiate between cable faults and faults on the high voltage bus in the transformer.
Evidence has shown that primary cable faults are much more prevalent than high voltage bus faults in transformers, switches, and junctions. To address the problem of cable faults, FCls need only be placed on the outgoing cables of transfomiers. Further reduction in the number of FCls installed could be realized by locating them at every other transformer or less. However, for each reduction in the number of FCls, the time to locate and isolate the faulted cable will increase. The customer outage time will also increase.
Faulted circuit indicators are affected by many items including cold load pickup, inrush, switching surges, lightning, and power follow currents. Proper application is essential to proper operation. FCIs should avoid tripping on inrush, cold load pickup, and switching surges and operate before protective devices.
Manual reset FCls require an operator to check and reset each indicator after each fault even;. The large variety of system conditions that occur on a distribution system makes it very difticult to create generalized application rules. Failure to reset the indicator can cause confasion for subsequent faults. Mechanical R’ls do not employ inrush restraint.
FCIs are available with a variety of resetting means that return a tripped unit to its normal state. Automatic reset typcs include reset by voltage, current. timc, or combinations of cacti. Some FCIs with automatic reset can also be reset manually when desired to facilitate troubleshooting.
Current reset FCIs will reset their indication when load current is sensed.
Voltage reselting fault indicators are not afTectcd by load current. Voltage resetting FCIs can be used on overhead or underground systems. There are several types of voltage resetting devices. The high and medium (primary) voltage resetting devices depend on the electrostatic field surrounding a high or medium voltage cable or a separable connector’s capacitive test point for operating power. The electrostatic reset type requires that the cable be unshielded and a test point reset type requires the use of a lest point type separable connector. The low (secondary) voltage resetting devices can only be applied wherever a secondary voltage is available and does not require a “test point type separable connector.” Minimum voltage levels and durations must be met for proper operation.
Time reset FCIs will reset after a selected period of time regardless of voltage or current status. When choosing the length of time before reset, the time chosen should be long enough to allow operating personnel time to locate and isolate the fault. If some or all of the units reset before this is accomplished, confusing information as to the location of the fault exists. In contrast, choosing an excessively long time can also cause problems if there is a subsequent fault before the units have had a chance to reset.
Self-adjusting FCIs automatically adjust the trip point depending on sensed load. These devices are “one size fits all” and can eliminate the need to have many difrerent fixed trip levels.
The basic function of an FCI is to detect fault currents and provide evidence that a fault current was detected. There are a variety of FCI display options available. The first decision is the type of display. The display can be a mechanical flag, audible alarm, light, counter, or other. When choosing an FCI display, the second consideration is whether the display is to be remote or integral. The integral display can be located on the primary cable immediately below the termination or on an elbow test point. This arrangement has the disadvantage of having to open the enclosure or substructure to observe the display. The remote display can be mounted so that it is visible without opening the enclosure. This design requires a sensor on the cable termination or elbow test point that can be connected to the remote display via cables, optics, radio, or other means.IEEE 1610 pdf download.
