CRMagnetics Catalog

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Technical Terms
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Operating Voltage A nominal voltage with a specified tolerance applied. The design voltage range to remain within the unit's
operating tolerances.
Phase Angle The difference in time by which an alternating signal lags or leads another signal. Phase angle may be a
measure of power factor when used to indicate the relationship of a voltage to current signal for a non-resistive
load. Phase angle may also be used to measure the different in phase between the primary and secondary of a
current or voltage transformer.
Polyphase Wattmeter A wattmeter consisting of 2 or 3 single phase wattmeters mounted in the same package. The watt sensing
elements can be electronic transducers. A dual element wattmeter will measure power in a 3 phase system
regardless of power factor, voltage or current variations between phases. Most common types are 2,2 1/2 or 3
element forms. In 4 wire circuits, with the 4th wire carrying current, the 2« or 3 element type is used. If
there is voltage imbalance, only the 3 element units can be employed.
Power A source or means of supplying energy. The unit of measurement is the watt. 1 Horsepower is equal to
745.7 Watts.
Range Nominal operating limits, specified by the lowest calibration point to the highest calibration point.
Rated Output The output at standard calibration
Ratios The relationship between the primary input value divided by the secondary output value. For example: a
current transformer that has a primary input value of 100 Amps and a secondary value of 5 Amps will have a
Current Ratio of 100:5 and a Turns Ratio of 20:1. It is important to use the term Current Ratio for most applica
tions because it defines the current handling capacity of wire used in the secondary winding. The
Turns Ratio only refers to the winding ratio and does not define the current handling capacity of the either
primary or secondary windings.
Real Power Same as Effective Power.
Reactive Power A component of apparent power (volt-amps) which does not produce any real power (watt) transfer.
Repeat Accuracy The maximum deviation from one timing operation to the next.
Self Powered The power required for correct operation of a transducer is supplied via the line being measured.
Separately Powered The power required for correct operation of a transducer is supplied via an external or auxiliary power
source, rather than via the line being measured.
Technical Terms (cont.)
Applications
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