COMBINED kW/kVA TRANSDUCER |
Datasheet (Adobe Acrobat Format)
Applications : Active and apparent power monitoring for indication or maximum demand control purposes.
This transducer converts both active and apparent power in 3-phase 3 or 4 wire systems into their D.C. equivalents, by means of Time-Division-Multiplication techniques.
Not only does this transducer provide accurate active and apparent power measurement, but its internal test points can, with the aid of an oscilloscope, be used to detect incorrect phasing as well as facilitate an assessment of the harmonic content. This information stems directly from observations of the voltage, current and power curves of each phase.
This transducer uses time-division-multiplication techniques, operating at high sampling rates, to multiply (3) the transformed voltage (1) and current (2) signals of each phase, and thereby produce the power signal for that phase. These three power signals (one from each phase) are summated (4) and transformed by the output amplifier (5) into a proportional d.c. current signal to provide the active power output.
The apparent power signal is derived by taking these same individual power signals and level shifting them (6) by an amount equal to the component of returned power, which effectively produces the absolute value of these power waveforms. These individual signals are then summated (7) and transformed by the output amplifier (8) into a proportional d.c. current signal to provide the apparent power output.
The auxiliary supply is transformed in P.T. (9), rectified and smoothed in regulator (10) and then used to power the multipliers, summators and output amplifiers.
| 1. Input quantities | |
| Voltage: | All standard values up to 600V |
| Burden: | 2.5 mA max |
| Overload in terms of rated input : |
1.73 x indefinitely 2.5 x 10 seconds |
| Current: | 0-1 A, 0-5 A (other values on request) |
| Burden : | 0.3 VA at rated input |
| Overload in terms of rated input : |
1.2 x indefinitely 40 x 0.5 second |
| Frequency: | 45 - 55 - 65 Hz |
| 2. Outputs | |
| NOTE : The output consists of two non isolated signals | |
| Characteristic: | A, C or E |
| Output quantity: | Impressed current signal(voltage signal on request) |
| Standard values: | 1, 5, 20mA unipolar |
| Maximum load: | 750 Ohm at 20mA(other values on request). |
| Maximum output voltage: | 25V D.C. |
| Maximum output current: |
1.25 x rated (typical) 2.00 x rated (maximum) |
| Ripple: | 0.5% standard |
| Response time: | 100 ms standard |
| 3. Auxiliary power supply | |
| Voltage: | 110V or 220V 50 Hz ±20%(other values on request) |
| Burden: | Typically 8.5 VA at rated load |
| 4. Accuracy | |
| Error limit at rated conditions: | |
| Active power | 0.5% |
| Apparent power | 1% |
| Linearity error: | 0.1% |
| Long term drift: | 0.25% |
| Temperature shift: | 400ppm/°C |
| Variation with auxiliary supply: | 0.05% for ±20% variation |
| 5. Protection | |
| Impulse test between isolated sets of terminals: | 5 kV (0,5J; 1,2/50 wave) (IEC Standard) |
| Voltage withstand rating between isolated sets of terminals: | 2 kV, 50 Hz A.C. for 1 minute |
| 6. Physical constraints | |
| Working temperature: | -25°C to 55°C. |
| Position: | Surface mounting in any position indoors. |
| 7. Enclosure | RG 2000: |