37
8.4.1
PRIMARY MEASUREMENT ACCURACY
•
Measurement error in environment of 18
°°°°
C to 25
°°°°
C (after 10’ warming up):
expressed as
±
% Rdg. (reading) + % F.S. (Full Scale) – see tables.
•
Additional measurement error outside this temperature range:
±
0,02% F.S. for each
°
C outside range.
•
Sensitivity and accuracy of voltage measurements:
Direct input with max voltage = 750 Vrms at Full Scale.
Input voltage peak factor
≥
1,6.
Input impedance
≥
4 M
Ω
.
Sensitivity, Full Scale and voltage accuracy
Rated
range
Sensitivity
Full Scale
ε
between 20% F.S.
and 100% F.S.
37 Vrms
24 mV
*
37,0 V
0,5%F.S.+ 0,5%Rdg.
174 Vrms
111 mV
174 V
0,3%F.S.+ 0,3%Rdg.
750 Vrms
480 mV
750 V
0,3%F.S.+ 0,3%Rdg.
(*) the minimum measurable signal is 1 V.
•
Sensitivity and accuracy of current measurement:
Direct input with max. 1 Vrms at Full Scale.
Input current peak factor
≥
1,6
Sensitivity, Full Scale and current accuracy
Rated
range
Sensitivity
Full
Scale
**
ε
between 20%F.S
and 100%F.S.
50 mV
32
µ
V
*
50 mV
0,5%F.S.+ 0,5%Rdg.
232 mV
140
µ
V
232 mV
0,3%F.S.+ 0,3%Rdg.
1 V
640
µ
V
1 V
0,3%F.S.+ 0,3%Rdg.
(*) the minimum measurable signal is 2 mV.
(**) Full Scales for 50,0 - 232 - 1000 Amp. with 1000 A/1V clamp meters provided
(Error = sum of inst clamp meter errors).
•
Accuracy does not take account of clamp meter error.
•
Voltage and current measurement precision as a function of frequency:
no error over errors specified in tables for signal frequencies in 20-90 Hz range.
8.4.2
SECONDARY MEASUREMENTS ACCURACY:
Power (single or three phase), Active Energy (and Power Factor) : class 1 (IEC 1036)
•
Measurement of other secondary values:
error is expressed by the formula which defines the value (sections 8.6.1, 8.6.2 and 8.6.3), as a function of V, I and
W.
