ELECTRONIC WATTMETER
TYPE EW15
The Convex model EW15 is a percentage power electronic wattmeter intended primarily for the accurate measurement of electrical power at load angles close to 90°. The unit has been designed specifically for testing Generator Low Forward Power Relays when used in conjunction with the PG250-LFP AC power supply but may also be used as a general purpose electronic wattmeter. (It has, for example, been found to be particularly useful for measuring the burdens of equipment connected to metering voltage and current transformers).
The unit will measure power over the range of inputs from 63V to 110V at 1A or 5A nominal for all load angles and will, in particular, measure power at load angles close to 90° with an accuracy of 0.1%.
The measured power, expressed as a percentage of the nominal full load power, is displayed on a centre-zero moving coil ammeter which has 3 switched ranges, -100/0/+100%, 10/0/+10% and -1/0/+1%. Calibration is straightforward and involves the adjustment of two preset multiturn potentiometers on the front panel of the unit.
The wattmeter is mains powered and presents low VA burdens at both the voltage and current inputs.
SPECIFICATION
POWER SUPPLY 240Vrms 50Hz 5VA.
INPUT VOLTAGE RANGE 63.5 to 110Vrms. Burden 0.15VA at 110Vrms.INPUT FREQUENCY RANGE 47 to 51Hz.INPUT CURRENT 1A or 5A nominal. Burden 0.6VA at 1A rms and 2VA at 5A rms.RANGES 3 switched ranges: 0 - 100% of full power 0 - 10% of full power 0 - 1% of full powerACCURACY ±1.5% of full scale on the 100% & 10% ranges. ±10% of full scale on the 1% range. (Maximum accuracy is ±0.1% of full power.)ENCLOSURE A two-tone grey metal case with adjustable carrying handle. Supplied complete with manual and leads. A padded carrying case is available, if required. Dimensions: W: 150mm H: 260mm D: 290mm (inc. handle). Weight: 4kg.
Convex Design Limited email:sales@convexdesign.co.uk
Return to
Home Page
2 & 3 Phase Power Supplies