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NVA100X - Getting started - 01 - 2018
ELECTRICAL CONNECTIONS
Electrical connections should be made by referring to the connection diagram;
CT-VT input versions
For the A1...A8 and B1...B10 , screw terminals with following characteristics are available:
• Nominal cross section:
0.2 to 4 mm
2
(AWG 24...10) for single conductor
0.2 to 1.5 mm
2
for two conductors with same cross section
• Tightening torque:
0.5-0.6 Nm
• Stripping length:
7 mm
For the IN1C-1...16, IN2D-1...16, OC1E-1...16 and OC2F-1...16 connections, screw terminals
with following characteristics are available:
• Nominal cross section:
0.14 to 2.5 mm
2
(AWG 26...16) for single conductor
da 0.14 to 0.75 mm
2
for two conductors with same cross section
• Tightening torque:
0.5-0.6 Nm
• Stripping length:
8 mm
For the X1...X6 (RS485 and blocks) connections, screw terminals with following characteristics are
available:
• Nominal cross section:
0.2 to 2.5 mm
2
(AWG 24...12) for single conductor
0.2 to 1.5 mm
2
for two conductors with same cross section
• Tightening torque:
0.5-0.6 Nm
• Stripping length:
10 mm
A protective ground connection is required, which must be connected to the suitable screw with a
separate lead of at least 4 mm2.
Amperometric inputs
In case of replacement of the relay or checks on the amperometric circuits is essential to provide
appropriate support to achieve the secondary circuit shorting. For security reasons it is advisable to
operate in the absence of line current.
When making the current connections, attention must be paid to not exceeding the performance of
the line current transformers. To be exact, the total load, constituted by the NA80 protective relay,
any other protective relays or measuring instruments and the resistance of the connections, must
not exceed the line CT performance.
In particular, consumption of the relay input circuit must not exceed 0.2 VA while the load (expressed
in VA) constituted by the conductors is given by:
0.018 × L ×
I
n
2
/ S
where:
L
the overall length, expressed in m, of the two conductors in relation to each phase;
I
n
nominal current of the line CT expressed in A;
S
cross sectional area of the current conductors expressed in mm2.
Devices must be installed by qualified personnel only.
No liability is accepted from Thytronic due to improper use.
CAUTION
If the secondary of a CT carrying primary current is open circuited, a high voltage can be developed
across the CT terminals.
CAUTION
Voltage inputs
Auxiliary power supply
Amperometric inputs
X1...X4 Block2
X5, X6 RS485
10
9
A
B
IN2D IN1C OC1E OC2F
Ground connection screw
Binary inputs
Output relays
NVA100X#JA2MM00
I
n
5A
U
AUX
110-230 Vac/dc
100V
100V
I
En
U
En
U
n
1A 1A
5A 1A
5A
