IEEE Std C93.3 pdf free download

IEEE Std C93.3 pdf free download.Power-Line Carrier Line Traps (30 kHz to 500 kHz).
5.2.4 Variation of blocking characteristics with change In ambient temperature and change in continuous current
5.2.4.1 Single- and two-frequency tuning
The resonant frequency shall not vary more than a total of 2% tbr changes in both the ambient temperature and the continuous current within the temperature range of—4() °C to ±45 °C, and from zero to rated continuous current.
5.2.4.2 Wide band tuning
For the field-adjustable type, the geometric mean frequency shall not vary more than a total of 2% for changes in both the ambient temperature and the continuous current within the temperature range of—40 °C to +45 °C, and from zero to rated continuous current.
For the factory-fixed type, the minimum blocking impedance over the bandwidth shall be maintained for changes in both the ambient temperature and the continuous current within the temperature range of—40 °C to +45 °C, and from zero to rated continuous current.
5.2.5 Auxiliary protective device rating
The “main” protective gap defined in 5.1 .8, is usually for lightning or high fault currents that, in turn, develop high voltages across the entire inductive coil of the line trap. This is typically referred to in line-trap literature as the lightning protective device.
Any “auxiliary” devices would typically be downstream for additional protective clamping for that particular downstream device unless the trap manufacturer decided to add additional levels of protection to back up this function. Any clamping or protective devices need to be self-restoring and auto-extinguishing of any spark activity. Auxiliary protective gaps shall neither sparkover nor continue to sparkover following transient voltage actuation, with the power frequency voltage, V as determined in 5.1 .. and 6.2.12 across the main coil.
6.2.2 Temperature rise at rated continuous current
6.2.2.1 General conditions
All temperature rise tests shall be performed in an indoor area as free from drafis as practicable. The area shall be sufficiently large so that the ambient temperature is not appreciably increased by heating effects of the line trap being tested. The line trap shall be fully assembled and shall be tested in each of the positions in which it is intended to operate.
There shall be sufficient clearance from the line trap to floors, walls, ceilings, and other objects in the test area so that there will be no hindrance to free natural convection or to normal radiation cooling.
Temperature rise tests shall be perfbrmed at rated continuous current and power frequency. It is permissible to shorten the time required tbr the test by the use of’ initial overloads or other suitable methods.
6.2.2.2 Ambient or cooling air temperature
The temperature of the cooling air shall be determined from the average of the readings of at least three thermometers or thermocouples placed unithrmly around the line trap at the same level as the bottom of the coil at a horizontal distance of one to two coil diameters from the edge of the coil. To reduce to a minimum, the errors due to time lag between the temperature of the line trap and the variations in the ambient temperature, the thermocouples or thermometers shall be placed in suitable containers. The container shall have such proportions as will require not less than two hours for the indicated temperature within to change 6.3 O if suddenly placed in air that has a temperature 10 0Q higher, or lower, than the previous steady-state indicated temperature within the container.IEEE Std C93.3 pdf download.