TRANSDUCER FOR AC CURRENT |
The transducer converts an AC current into a load independent DC current or voltage signal which may be used to drive a number of remotely installed instruments.
The measuring principle is "arithmetic mean calibrated to RMS sinusoidal" and this transducer is therefore only suitable for undistorted sine wave measurements.
The normal response time is suitable for indicating instruments and recorders. A lower ripple - slower response version for data loggers can be supplied.
The output is protected against over-voltages due to surges or accidental contact with insulation testers or the mains supply.
The auxiliary voltage supply is user selectable to either 110V or 220V AC by means of a jumper. Similarly the input range may be changed to either 0-1A or 0-5A.
The current to be measured is transformed in and converted in the active rectifier(3). The auxiliary supply is transformed in PT (2), rectified and smoothed in (4) and is used to power the rectifier (3), output amplifier (5) and to provide the offset voltage for the live zero version. The output amplifier (5) provides either a load independent current (with maximum burden) or a load independent voltage (with minimum burden) signal.
| 1. Input | |
| Input quantity: |
User selectable 0 - 1 A or 0 - 5 A |
| Frequency: | 45 - 55 - 65 Hz |
| Consumption burden: | 0.3VA at rated input |
| Overload in terms of rated input: |
1.2x indefinitely 40x 0.5 seconds |
| 2. Output | |
| Characteristic: | A or C or D |
| Output quantity: | Impressed current signal (voltage signal on request) |
| Standard values: | 1mA, 5mA, 20mA |
| Maximum load: | 5k, 2.5k, 750 Ohm |
| Maximum output voltage: | 32V DC |
| Maximum output current: |
1.25x rated (typical) 2.0x rated (maximum) |
| Ripple: | 0.5% standard |
| Response time: | 210ms standard |
| 3. Auxiliary power supply | /|
| Voltage: |
User selectable 110 or 220V 50Hz |
| Burden: | <3.5VA at rated output |
| 4. Accuracy | |
| Error limit at rated conditions: | ±0.5% of range at 23°C and 45-55 Hz sinusoidal wave, form factor 1.11 |
| Linearity error: | 0.05% |
| 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: | 5kV (0.5J 1.2/50 wave) IEC standard |
| Voltage withstand rating between sets of terminals: | 4kV, 50Hz AC for 1 minute |
| Power voltage across output: | 220V, 50Hz indefinitely |
| Surge across output terminals: |
5kV 25J 1kV 4J |
| 6. Physical constraints | |
| Working temperature: | -25 to 13 to 33 to 55°C |
| Storage temperature: | -55 to 75°C (above dewpoint) |
| Relative humidity: | 80% |
| Variation due to external magnetic field (worst case): | 0.05% at 400A/m 50Hz |
| Position: | Surface mounting in any position indoors. |
| 7. Enclosure |
DIN A LDG10 |