Connecting Of The Device - Applied Precision RS 2130 User Manual

The three phase version of the device is equipped with three independent channels L1, L2, L3. Each of
them has two inputs: Current input (CURRENT) and voltage input (VOLTAGE). The inputs are insulated
from each other; therefor its connection is arbitrary. The basic connection of the voltage and current
clamps (only for one channel) for indicating of positive power (energy) is shown on the
Figure 1.
The benefit of this connection is that its own input current of the voltage input of the device does not
load the current input of the device. The measurement error caused by the volt drop on the current
clamps is negligible due to use of electronically compensated current transformer in the current input.
Phase
Neutral
Earth
The inner ground of the electronic circuits connected to the GND clamp is common for both analogue
and digital circuits. The input voltage clamps Lo and Hi are in a differential connection against the GND,
i.e. the device measures the voltage difference between the clamps Lo and Hi. Each of the Lo and Hi
clamps can be loaded by operating voltage up to 500V against the GND clamp.
The positive orientation of the voltage difference is defined as U
The positive orientation of the current is from the clamp In to the clamp Out.
The lowest error caused by the finite symmetry of the potential input circuits can be reached by
connecting the neutral wire (or the wire with the lowest voltage against the guard wire) to the Lo input
clamps and the phase wires to the Hi clamps. The inner ground of the device, that is GND clamp, is
connected to the safety ground i.e. to zero voltage.
When connecting the device as an independent measuring device without connecting of the
communication channels, there is no grounding connected from the outside power supply. In this case
it is appropriate to connect the inner ground with the lowest potential by connecting the GND clamp with
the Case/Earth clamp and thus to the guard wire in the socket outlet.
8

2.4 Connecting of the Device

CURRENT
In
Out
Hi
VOLTAGE
Lo
CASE/EARTH
Figure 1
RS-UG91-EN
Reference Standard RS 2x30, RS 1x30
Load
GND
User's Guide
- U .
hi Lo
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