Current Measurement Specifications; Current Input Capability And Characteristics - XITRON XT2640 Operating Manual

Total Scaling errors = ±0.032645% of reading
Floor Errors:
Base Floor = 450µV
DC Floor = (0V/230V)*1mV = 0
AC floor = (100µV/230V) at MAINS = 0.43µV (can be ignored)
Common‐Mode = if not 3ø3w(2ch) wiring = none
Common‐Mode = if 3ø3w(2ch) wiring = 1µV*(230V/√3)*50Hz = 6.6mV at (30+90)° = ±3.3mV
Total Floor Errors = ±0.45mV or ±3.75mV = 0.0002% or 0.0016% of reading
Example 2
For an A type channel the maximum error of a measurement of the fundamental of a 230Vrms voltage at 50Hz when 50 harmonics
are configured is a worst case of ±0.035% of reading as calculated by:
Scaling Errors:
Base Scaling = ±0.03%
Frequency Dependent Scaling = None at MAINS
Self‐heating Scaling = ±0.05%*(230V/1000)
Temperature Scaling = none within 5C of the calibration temperature
Bandwidth Limit Scaling = none when using AUTO‐TRACK
Total Scaling errors = ±0.032645% of reading
Floor Errors:
Base Floor = 450µV
AC floor = (100µV/230V) at MAINS = 0.43µV (can be ignored)
Common‐Mode = if not 3ø3w(2ch) wiring = none
Common‐Mode = if 3ø3w(2ch) wiring = 1µV*(230V/√3)*50Hz = 6.6mV at (30+90)° = ±3.3mV
Total Floor Errors = ±0.45mV or ±3.75mV = 0.0002% or 0.0016% of reading
Harmonic Amplitude Errors:
(H/N) *0.3% of reading = (1/50)*0.03% = ±0.0006%
2
Is fundamental, so no further harmonic amplitude error
Total Harmonic Amplitude Errors = ±0.0006% of reading
Example 3
For an A type channel the maximum error of a measurement of a 10%THD of a 230Vrms voltage at 50Hz when 50 harmonics are
configured is a worst case of ±0.10% as calculated by:
(0.005+0.000025*N)*%THD = (0.005+(0.000025*50))*10 = 0.0625%THD
0.00005*N*√N = 0.00005*50*√50 = 0.0177%THD
0.015+1/V = 0.015+1/230 = 0.0193%THD
AC
Example 4
For an A type channel the maximum error of the inter‐channel voltage fundamental phase at 50Hz is a worst case of
0.02°+0.15°*0.05 = ±0.021°
Example 5
For an A type channel the maximum error of the crest factor of a 230V/50Hz voltage is a worst case of 50mV/230V = 0 to +0.00022
(i.e. biased to a higher reading)
28.3 CURRENT MEASUREMENT SPECIFICATIONS
28.3.1 CURRENT INPUT CAPABILITY AND CHARACTERISTICS
Specification
<8ms
<40ms
No Damage
Current Range
Continuous
XT2640 Unpowered
Measurable Current Range
Specified Current Range
Impedance Burden
3dB Bandwidth (typical)
XT2640 Operating Manual
= ±0.002645%
2
Channel
Option H
Type
<200A and
RMS
All
<300A
PK
All <75A
RMS
<1s All <50A
RMS
All <30A
RMS
All As Above
All <225A and A
RMS PK
All <30A and <200A
RMS PK
All 2.5mΩ to 7mΩ
S, A or L
W
13 July 2016
Option D HI Range Option D LO Range
or Auto‐Range when or Auto‐Range when
on HI Range on LO Range
<150A and
RMS
<60A and <150A
RMS
<250A
PK
<50A <40A
RMS RMS
<30A <5A
RMS RMS
<20A <2A
RMS RMS
<2A and <150A
RMS PK
<150A and A <1.02A and A
RMS PK RMS
<20A and <140A <1A and A
RMS PK RMS
4mΩ to 12mΩ 0.562Ω ± 0.75%
1.25MHz
5MHz
Option X HI Range Option X LO Range
<200V and
RMS
<20V
PK
<300V
PK
<50V
RMS
<30V
RMS
<25V and V <5V
RMS PK
<25V and <300V
RMS
<23.1V and V <0.576V
PK RMS PK
<15V and <20V <0.55V
PK RMS PK
20.5kΩ ± 0.25% 10.25kΩ ± 0.25%
3MHz
Page 169 of 187
and <30V
RMS PK
<10V
RMS
<5V
RMS
and V
RMS PK
PK
and V
RMS PK
and V
RMS PK