Software

EPR, For load measurements in MV and LV distribution networks

The EPR-1 and EPR-31 Portable Recorders are designed for in and out-door measurements of electrical parameters. Both recorders have identical housing, internal electronics and measurement capabilities. They only differ by their external measurement interfaces.

EPR-1

EPR-1 measures currents in MV network overhead lines. It is hooked directly on the cable where the passing current has to be measured. EPR-1 has 1 measurement channel. On the top-side of the EPR-1 is fixed a hook allowing to easily hook the recorder on bare or insulated live lines using a conventional hot stick.

Measurement ranges are 0-200 Amps or 0-1000 Amps.

EPR-31

EPR-31 measures voltage and currents in LV networks. The hook of the EPR-1 is replaced by 4 input connectors:

• 1 channel V for voltage measurement
• 3 channels I1, I2, I3 for current measurements by clamp-on transformers

The EPR-1 and EPR-31 battery autonomy guaranties operation for at least 500 hours. Memory capacity allows for storage of up to 20 000 measurements. For programming the EPRs, and for reading and processing the measurements, they connect to a PC using RS-232 serial interface.

EPR-31 input connectors

On the top-side of the EPR-31 there are 4 connectors. The first connector (channel V) is used to measure Vac voltage. Channels I1-I3 are usually used for current measurements using clamp-on transformers clipped on LV network conductors.

The voltage channel has the following measurement ranges: 0-10, 0-150, 0-300, 0-500 Vac. The applicable range is selected by jumpers which are accessed when the front panel is removed.

The 'current' channels receive 0-1, 0-5 or 0-10 Vac or Vdc input signals, usually coming from clamp-on current transformers. Such transformers are available for the following ranges: 50, 100, 200, 300, 500 and 1000 Amps.

EPR-31 may also be programmed to measure the phase angle (cos n) between the V- and the I1 channels.

EPRLINK Software

Before installing the EPR recorder for a measurement campaign, it is programmed using the EPRLINK software on a PC. With this program, the user defines begin- and end times of the measurements, type and frequency of measurements, etc. Through a RS-232 connection, these parameters are downloaded in the EPR's memory, and the EPR's real-time clock is adjusted to the PC clock.

Between measurement start- and stop times, samples are taken every 5 seconds. Then, every n minutes (0 < n < 60 as programmed by user), the average value of those samples, or their maximum value (as programmed) is stored in memory. Each value is stored in 1 byte (8 bits resolution, no sign).

When pressing the button on the right panel, the LCD displays the programming parameters and the most recent measurement value for each channel. This allows verifying correct programming and correct operation of the recorder.

After the measurement campaign, EPRLINK is used to extract from the EPR's memory the stored measurements and to display the measurement curves on the screen. The measurement curves can be displayed in various resolutions, they can be printed, or they can be stored or exported for in-depth analysis with other specialised tools, such as spreadsheets.

The EPR-31 can also be used to measure any physical quantities (temperatures, pressures, flows, ...) converted by appropriate sensors to the EPR-31 input signals.