WP-14000-4 Precision Voltage
The WP140004 Transformer is primarily a
laboratory standard. Its excellent accuracy and the Knopp One-to-One calibrating feature
make it well-suited as a standard for precision calibrating work. With the aid of this
transformer, very accurate determination can be made of the ratio and phase angle
characteristics of voltage instrument transformers having ratings from 120 volts to 14,400
The range of a 120 volt voltmeter or wattmeter can
be accurately extended by this transformer to cover all voltage values up to 14,400 volts.
The primary ranges are: 120, 240, 288, 300, 480,
600, 2400, 4200, 4800, 7200, 8400, 12000 and 14400 volts. The secondary is 120 volts.
BURDEN AND ACCURACY
The WP140004 Transformer, like other
Knopp Precision Multirange Transformers, has excellent ratio and phase angle
characteristics with respect to both inter-range accuracy and overall accuracy. This is
made possible through a properly engineered design and through exclusive, highly perfected
compensating and winding methods.
The transformer is furnished compensated for the
highest possible accuracy at the burden specified by the purchaser, but it may be used
with excellent results with other burdens up to 25 volt-amperes. When used with the burden
for which compensated, 15 volt-amperes to give an example, the ratio of this transformer
standard is well within .02% and the phase angle is well within 2 minutes on all ranges.
The transformer is an absolute standard as it can be
calibrated against itself without a standard of comparison by means of the Knopp
For long, dependable service the coil is cast in
epoxy, and the core and coil assembly is housed in a beige Emcor steel case with engraved
aluminum panel fitted with porcelain high-voltage bushings. The approximate overall
dimensions are: 20 in. wide (not including the handles), 15 in. deep, and 18 in. high
including the bushings.
The net weight of the WP140004 is
approximately 175 pounds and the shipping weight is approximately 250 pounds. A
rubber-tired dolly is available for use with this transformer to make the unit readily
mobile. The dolly's net weight is 17 pounds, and its shipping weight is approximately 30