UFC 3-535-01
17 November 2005
completely resistive, the KW rating may be used as an approximation.
13-16.1.5
Size the regulators rated 10KW and above to match connected load with
50 percent to 100 percent of rated load. Taps on regulators are recommended to help
match connected load with rated load and provide a means to accommodate load
changes in the system.
13-16.1.5.1 For resistive loads: In the range of 50 percent to 100 percent of the
nominal load at rated input voltage, with output current at 100 percent, the efficiency
and power factor should not be less than the values specified by FAA AC 150/5345-10.
[Efficiency not less than 80 percent; power factor not less than 0.90.]
13-16.1.5.2 For reactive loading: The regulator is required to maintain the current
within the permitted tolerance for all current steps when the load is connected via
isolation transformers and the secondary of 30 percent of these transformers become
open-circuited. The load before opening the isolation transformers may be of any value
between 50 percent and 100 percent of the nominal load.
13-16.1.6
The regulator should generate minimum harmonics on the input power
lines. Third harmonics should be reduced as much as possible, sufficient to meet IEEE
standards (IEEE 519-1992, Recommended Practices and Requirements for Harmonic
Control in Electrical Power Systems, Chapter 10). [From Chapter 10: "It would be ideal
if it were possible to control harmonics to such an extent that harmonic effects caused
by connections of harmonic-producing loads were nil at every point in the entire system
encompassing the consumer's own circuit."]
13-16.1.7
For compatibility of the regulator with the equipment powered by the
regulator (such as signs), the manufacturer should be required to supply with the
qualification documents oscilloscope photo/printouts of output current and voltage
waveforms at nominal line voltage for all brightness steps, in short circuit, at half load,
and at full load. The half-load and full-load waveforms should be taken with pure
resistive loading, then repeated with 30 percent isolation transformers open circuit. The
output waveforms provide a means for manufacturers of equipment to be connected to
ensure compatibility with approved regulators.
13-16.1.8
Isolation of high voltage equipment (1000V or greater) from the low
voltage equipment, either by construction when in the same location, or by separation
within the regulator.
13-16.1.9
The doors for access to high voltage components within the regulator
should be equipped with safety door interlocks that de-energize the regulator before
access is gained, and prevent energizing with the door opened. The door should be
fitted with an appropriate label, such as: DANGER HIGH VOLTAGE, DE-ENERGIZE
SWITCH BEFORE OPENING THIS DOOR.
13-16.1.10 Regulator cabinets should be designed for easy movement to facilitate
installation (i.e., rollers or lifting rings) and should also have an additional ground
terminal to connect cable shielding.
216
Previous Page
