Thytronic NA10 User Manual

FUNCTION CHARACTERISTICS
26
NA10 - Manual - 04 - 2022
4.3 I/O DESCRIPTION
Metering inputs
The following input are provided:
• Three phase current inputs.
• One residual current input.
• The nominal currents are independently adjustable at 1 A or 5 A through DIP-switches.
The input circuits are appropriately dimensioned in order to withstand the currents which arise
when a fault occurs, both in transient and steady state condition.
Signal processing
Various processing levels are involved:
• Acquisition (base level).
• Direct measures of physical channels (first level).
• Calculated measures (second level).
• Derived (third level).
The measures concerning a level are based on data worked out in the previous level.
For each level the required resources concerning the priority for tasks (conditioning circuits, DSP
and CPU) are on hand.
ACQUISITION (base level)
The input signals are sampled 24 times per power cycle
- i
L1
...i
L3
phase currents instantaneous value
- i
E
residual current instantaneous value
From the sampled quantities, several measures are computed for protection, monitoring and meter-
ing purposes.
• Direct
• Calculated
• Harmonics
• On demand
Direct
• Power frequency.
sensori.ai
NA10
3 phase current inputs
one residual current input
acquisition.ai
ACQUISITION
INSTANTANEOUS VALUES
≈
F.ai
(Hz)
ACQUISITION
I
L1
I
L2
CT
I
L3
i
L1
i
L2
≈
≈
i
L3
≈
f
T

Thytronic NA10 Specifications

General

Brand	Thytronic
Model	NA10
Category	Relays
Language	English