MI 2893 / MI 2892 / MI 2885
Transient recorder
84
3.16
Transient recorder
Transient is a term for short, highly damped momentary voltage or current disturbance.
Table 63: Transients on the low voltage network
Rise time
Cause
>100 µs
Operation of current-limiting fuses (amplitude up to 1 kV – 2 kV)
Activation of capacitors banks for power factor corrections (amplitude up tp
2 -3 times of nominal peak voltage)
Transference of switching transient over voltages from MV to LV across
MV/LV transformers by electromagnetic coupling (amplitude up to 1 kV)
1 µs to 100 µs
Direct lightning stroke on the LV line conductors (amplitude up to 20 kV)
Induction coupling of a lightning stroke in a vicinity of an L line (amplitude up
to 6 kV, high energy levels)
Resistive coupling associated with lightning currents flowing in the common
earth paths of network (amplitude up to 10 kV)
Transference of transients from MV to LV by capacitive transformer coupling
(amplitude up to 6 kV)
Operation of fuses (amplitude up to 2 kV, low energy content generally)
<1 µs
Local load switching od small inductive currents and short wiring (amplitude
up to 2 kV)
Fast transients due to switching in LV by air-gap switches
3.16.1
Power Master XT - MI 2893
A transient recording is recording with the 1 MSamples/sec sampling rate. The principle of
measurement is similar to waveform recording, but with higher sampling rate. In contrary to waveform
recording, where recording is triggered based on RMS values, trigger in transient recorder is based on
sample values.
Notes:
-
To detect voltage transients at 3W connection, GND terminal should be connected according
the proposed connection. Trigger selection should be selected as “GND”;
-
To detect voltage transients at Open Delta connection, GND terminal should be connected
according the proposed connection. Trigger selection should be selected as “GND”. For
detecting transients in L2 current, also L2 current clamps should be connected;
-
Transient measurements (high frequency events) on the secondary side of transformers
(current and voltage transient measurements) could suppressed and/or distorted due to narrow
frequency response of transformers. Same effect could be also present when measuring
transients with the flex current clamps;
-
For proper current transient measurements, it is obligatory to use fixed current range.
3.16.1.1
Setup
Transient recorder setup menu is available from:
MAIN MENU
MEASUREMENT SETUP
TRANSIENT SETUP
or
