POM2-3333
Merger Unit Test User
Manual
56
burdens of between 25 % and 100 % of the rated burden, at a power factor of 0,8 lagging.
The errors shall be determined at the terminals of the transformer and shall include the
effects of any fuses or resistors as an integral part of the transformer.
Table 4
Accuracy
class
Percentage voltage (ratio) error ±
Phase error ±
Minutes
Centiradians
0.1
0.10
5.0
0.15
0.2
0.2
10
0.3
0.5
0.5
20
0.6
1
1.0
40
1.2
3
3.0
Not specified
NOTE 1:
The normal value of phase error
should be zero. However, different values can be specified
when the electronic voltage transformer must be used in combination with other electroni
c
voltage transformers or electronic current transformers in order to have a common value.
C.4 Limits of voltage error and phase displacement error
for electric protective voltage transformers
The standard accuracy classes for protective electronic voltage transformers are 3P and
6P, and the same limits of voltage error and phase displacement will normally apply at
both 5 % of the rated voltage and at the voltage corresponding to the rated voltage factor.
At 2 % of the rated voltage, the error limits will be twice those at 5 % of the rated voltage.
When electronic voltage transformers have different error limits at 5 % of the rated voltage
and at the upper voltage limit (i.e. the voltage corresponding to the rated voltage factor 1,2
or 1,5 or 1,9), agreement should be made between manufacturer and purchaser.
Table 5
Accuracy
class
Up/Upn %
2%
5%
x% (the rated voltage
factor)
ε
u
±
φ
e
minutes
±
φ
e
Centi-radians
±
ε
u
±
φ
e
minutes
±
φ
e
Centi-radians
±
ε
u
±
φ
e
minutes
±
φ
e
Centi-radians
±
3P
6
240
7
3
120
3.5
3
120
3.5
6P
12 480
14
6
240
7
6
240
7
NOTE 1:
The normal value of
ϕ
0n should be zero. However, different values can be specified when
the electronic voltage transformer has to be used in combination with other electronic
voltage transformers or electronic current transformers in order to have a common value.
