Protected Object
Line, transformer, etc
ForwardReverse
Definition of direction
for directional functions
Measured quantity is
positive when flowing
towards the object
e.g. P, Q, I
ReverseForward
Definition of direction
for directional functions
e.g. P, Q, I
Measured quantity is
positive when flowing
towards the object
Set parameter
CTStarPoint
Correct Setting is
"ToObject"
Set parameter
CTStarPoint
Correct Setting is
"FromObject"
en05000456-2.vsd
ANSI05000456 V2 EN-US
Figure 5: Internal convention of the directionality in the IED
If the settings of the primary CT is correct, that is
CTStarPoint
set as
FromObject
or
ToObject
according to the plant condition, then a positive quantity always flows towards the protected
object, and a
Forward
direction always looks towards the protected object.
The settings of the IED is performed in primary values. The ratios of the main CTs and VTs are
therefore basic data for the IED. The user has to set the rated secondary and primary currents and
voltages of the CTs and VTs to provide the IED with their rated ratios.
The CT and VT ratio and the name on respective channel is done under Main menu/Hardware/
Analog modules in the Parameter Settings tool or on the HMI.
3.7 Technical data
SEMOD55412-1 v1
M16988-1 v11
Table 28: TRM - Energizing quantities, rated values and limits for protection transformer
Description Value
Frequency
Rated frequency f
r
50/60 Hz
Operating range f
r
± 10%
Current inputs
Rated current I
r
1 or 5 A
Operating range (0-100) x I
r
Thermal withstand 100 × I
r
for 1 s *)
30 × I
r
for 10 s
10 × I
r
for 1 min
4 × I
r
continuously
Dynamic withstand 250 × I
r
one half wave
Burden < 20 mVA at I
r
= 1 A
< 150 mVA at I
r
= 5 A
*) max. 350 A for 1 s when COMBITEST test switch is included.
Table continues on next page
1MRK 502 066-UUS B Section 3
Analog inputs
79
Technical manual
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