Sub.net has 4 concurrent recording modes that provide data for a wide range of applications. The recording speeds and periods cover the range of variations that are found on power networks.

Waveform recording

This mode records the analogue and contact inputs at 128 samples per cycle. This is equivalent to 6.4kHz for a 50Hz supply and 7.68kHz for a 60Hz supply. All the inputs are sampled at the same time with no channel skew.

This is used for high speed events like protection operations or power quality sub-cycle events. If there are multiple limit excursions there can be multiple waveform records in one event report.

RMS/Swing recording

A selection of up to 85 input and computed quantities are recorded at one sample per cycle. These inputs are selected from the RMS inputs, frequency, power, power factor, sequence components and contact inputs. The data are used for longer events like recloser sequences and power and frequency oscillations. The recording time is dynamic and will extend if the trigger condition continues.

RMS log

This is a continuous recording of 12 key values at 10 samples per second. The input options are the same as those for the RMS recorder. The RMS log contains the measurements from the previous 14 days. This creates a large amount of data and small intervals may be examined for small measurement variations which were insufficient to create an RMS record.

Trend log

Trend recording is a continuous record of over 800 measurements with the max, min and average saved every ten minutes. The inputs are the average values of the RMS inputs, harmonics, flicker, frequency, power, power factor and sequence components. The log contains the measurements from the previous 26 weeks. The ten minute interval is synchronised to the real time clock and is used to meet standards including EN50160, EN61000-4-7, EN61000-4-30 & G5/4.

For higher resolution applications there is an option for 1 minute trend intervals. This should be requested at time of ordering.