Thytronic NA016, Manual

Page: 27 / 69

FUNCTION CHARACTERISTICS
27 NA016 - Manual - 05 - 2022
4.4 PROTECTIVE ELEMENTS
Rated values
Traditional CT inputs
• Relay phase nominal current I
n
The rated value must be set by means dip-switch to 1 A or 5 A, same as the secondary CTs nominal
current.
• Relay residual nominal current I
En
The rated value must be set by means dip-switch to 1 A or 5 A, same as the secondary nominal
current of the residual CT.
Dip-switch is located on the CPU board; the exhaustive treatment of Dip setup is described in the
“6.4 SETTING NOMINAL CURRENTS I
n
AND I
En
” paragraph.
Low Power CT inputs
• Relay phase nominal current I
n
The rated value must be set by means dip-switch to 50 A to 1250 A, same as the primary nominal
current of the protected plant. All settings of the current thresholds are referred to the rated cur-
rent of the relay I
n
, that corresponds to the primary value automatically set as just described.
Dip-switches are located on the rear board; the exhaustive treatment of Dip setup is described in
the “6.5 NOMINAL CURRENT In SETTING FOR LPCT” paragraph.
• Relay residual nominal current I
En
• The rated value must be set by means dip-switch to 1 A or 5 A, same as the secondary nominal
current of the residual CT.
Dip-switch is located on board of the CPU board; the exhaustive treatment of Dip setup is de-
scribed in the “6.4 and 6.5 SETTING NOMINAL CURRENTS I
n
AND I
En
” paragraph.
Settings
Inside the Set \ Base menu the following parameters can be set:
• Primary rated values (phase and residual), employed for measures relative to primary values.
• Measurements reading mode (
Reading Direct or Relative
).
• Phase CT primary current I
np
This parameter affects the measure of the phase currents when the primary measurement reading
mode is selected (
Reading Direct
). It must be programmed to the same value of the phase CT
primary nominal current Traditional CTs) or to the value set for the LPCT inputs.
• Phase CT primary current I
np
This parameter affects the measure of the phase currents when the primary measurement reading
mode is selected (
Reading Direct
). It must be programmed to the same value of the phase CT
primary nominal current Traditional CTs) or to the value set for the LPCT inputs.
Example
The phase CT primary current I
np
must be set as: I
np
= 500 A
• Residual CT primary current I
Enp
This parameter affects the measure of the residual current when the primary measurement read-
ing mode is selected with traditional CTs inputs. It must be programmed to the same value of the
residual CT(s) primary nominal current.
Example 1
Es-In.ai
K
TA
= 500A/5A=100
52
I
n
NA016
I
L1...
I
L3
LPCT
s CURRENT INPUTS
L1
L2
In = 500 A
In = 500 A
In = 500 A
LPCT Setting
800 A
400 A
200 A
100 A
50 A
L3
In=50...1250A
1A/5A
Es1-IEn.ai
1x
K
TA
= 100 A /1 A
52
I
En
= 1 A
NA016