Winding Resistance Measurement Accuracy; Ratio And Phase Measurement Accuracy - Omicron CT SB2 User Manual

CT Analyzer User Manual
Table 12-4: Measurement input PRIM
Characteristic
Voltage ranges
Accuracy
Insulation
12.4

Winding resistance measurement accuracy

Table 12-5: Winding resistance measurement accuracy
Characteristic
Resolution
Accuracy
12.5

Ratio and phase measurement accuracy

The values given in the following table are only valid under the following conditions:
• All utility lines to the primary side of the CT are disconnected.
• One terminal of the primary side of the CT is connected to PE.
• The original measurement cables delivered by OMICRON for CT Analyzer are used.
• The CT under test is a CT with a non-gapped core.
• The knee point voltage according to IEEE C57.13 is > 3V.
Under interfering conditions the device has reduced accuracy.
Values without the prefix "!" in the ratio table of the Ratio card have guaranteed accuracy. The accuracy
of values marked with a "!" in the table is reduced by factor 2 since these values are not directly
measured but calculated from the measured values instead.
Table 12-6: Ratio measurement accuracy for 1 A CTs at rated current
CT ratio
0.2 - 1
> 1 - 2000
> 2000 - 5000
> 5000 - 10000
1. Nominal burden of the CT.
170
Rating
0 - 0.03 / 0.3 / 3 / 30V
AC
0.1% (guaranteed)
Reinforced insulation (R) to all other circuits
Rating
Ω
1m
0.05% (typical)
Ω
0.1% + 1m (guaranteed)
I Rated power
sn
1 1.0 - 30VA
1 0 - 30VA
1 0 - 30VA
1 0 - 30VA
(auto ranging)
1
Typical accuracy
0.05%
0.02%
0.03%
0.05%
Guaranteed
accuracy
0.1%
0.05%
0.1%
0.2%
OMICRON