ERL tesla lite, User Manual, Page: 93 / 288

8 Configuring the Recorder
D03283R01.10 TESLA LITE User Manual 8-15
8.6 Analog Input Channels
Description
Basic recording channels for the recorder’s analog input signals.
Input
The recorder’s physical analog input channels.
Calculation
The rms amplitude of the fundamental is calculated using a DFT function. The
resultant phasors are used for rate and level triggers, metering, low speed re-
cording, trending and sag/swell detection. The single harmonic and THD de-
tectors are calculated directly from the input samples.
Triggers
• High & low magnitude
• Negative and positive rate of change
• Single harmonic magnitude
• THD magnitude
• Sag and swell
To prevent multiple triggers on threshold conditions, an hysteresis of 2% of
setting is applied to magnitude triggers.
Recording
High Speed : records the samples generated from the A/D converters at 96 sam-
ples per cycle.
Low Speed : records the calculated phasors at a rate of one phasor per cycle.
Number of
Channels
Up to 18 Analog Input Channels can be defined, one for each physical input.
Types
Specific: Va, Vb, Vc, Ia, Ib, Ic, In (use where appropriate)
Generic: Vac, Iac
Notes
The Analog Input Channel also produces THD and Single Harmonic readings
that are available to the metering display, SCADA and the long term trending
function.