Sonel MPI-540 - Sampling and RTC; Voltage Measurement

MPI-540 ● MPI-540-PV – BRIEF USER MANUAL
67
Current input terminals
Number of inputs
3 (L1, L2, L3) not galvanically insulated from one another
Maximum peak input
voltage
5 V relative to earth
Nominal input voltage
(hard clamps)
1 V
RMS
Peak input voltage (hard
clamps, without cutting)
3.6 V
Analogue transmission
band (-3dB)
12 kHz
Input Impedance
Path for hard clamps: 100 k
Path for flexible clamps: 12.4 k
Measurement range
(without transformers)
Flexible clamps F-1(A)/F-2(A)/F-3(A): 1..3000 A (10000 A peak, 50 Hz)
Hard clamps C-4(A), C-5(A): 1..1000 A (3600 A peak)
Hard clamps C-6(A): 0,01..10 A (36 A peak)
Hard clamps C-7(A): 0..100 A (360 A peak)
Transformers
defined by user
CMRR
60 dB (50 Hz)
8.2.2 Sampling and RTC
A/C converter
16-bit
Sampling rate
5.12 kHz for 50 Hz and 60 Hz
Simultaneous sampling in all channels
Samples per period
102.4 for 50 Hz; 85.33 for 60 Hz
PLL synchronization
40..70 Hz
Reference channel for
PLL
L1-N, L1-L2 (depending on the type of network)
Real-time clock
30 ppm (approx. 2.6 s/day)
8.2.3 Voltage measurement
Voltage
Range and conditions
Resolution
Accuracy
U
RMS
(AC+DC)
20% U
nom
≤ U
RMS
≤ 120% U
nom
for U
nom
≥ 100 V
0.1% U
nom
0.5% U
nom
Crest factor
1..10
(1..2.2 for voltage 500 V)
for U
RMS
≥ 10% U
nom
0.01
5%