1. Installation
1.1 Physical
The instrument is built in a plastic box to be installed in a distribution board panel. The instrument’s position must be fixed with locks. Put the locks into square inserts placed
diagonally on the top and bottom of the box and tighten the screws to the panel.
Natural air circulation should be provided inside the distribution board cabinet, and in the instrument’s neighbourhood, especially underneath the instrument, no other
instrumentation that is source of heat should be installed.
1.2 Instrument Connection
1.2.1 Power Supply
The instrument requires an
AC or DC voltage power supply as specified in technical parameters.
The supply inputs are separated from other circuits of the instrument.
It is necessary to connect an auxiliary supply voltage in the range as declared in technical specifications table to the terminals
AV1
( No. 9, L ) and
AV2
( No.10, N ). In case
of DC supply voltage the polarity of connection is generally free, but for maximum electromagnetic compatibility the grounded pole should be connected to the terminal
AV2
.
The supply voltage must be connected via a disconnecting device ( switch - see installation diagram ). It must be situated directly at the instrument and must be easily
accessible by the operator.
The disconnecting device must be labelled as the disconnecting device of the equipment.
A C-character double circuit breaker at the nominal
value of 1A may be used for the disconnecting device; however its function and position must be clearly marked (symbols „O" and „I" according to EN 61010 – 1). If one of the
supply signals is neutral wire N (or PEN) usually a single breaker in the line branch is sufficient. If a switch and fuse is used, the T1A (delayed) type is recommended.
Since the instrument’s inbuilt power supply is of pulse design, it draws a momentary peak current on powerup which is in order of magnitude of amperes. This fact needs to
be kept in mind when selecting the primary protection devices.
1.2.2 Measured Voltages
Connect measured voltages in wye ( star ), delta or Aron configuration to terminals
VOLTAGE / N
(No. 11),
U1
(No. 12),
U2
(No. 13), and
U3
(No. 14). The
N
terminal stays
free at delta and Aron connections. Phase rotating direction is free.
It is advisable to protect the supply leads by 1A safety fuses (F1A type, for example).
The type of voltage and currents connection must be entered in
Installation
parameters : the code shows the amount of connected phases,
3Y
means three-phase connection
in wye ( star ),
3D
in delta.
3A
means Aron connection. For
1Y3
or
1D3
setup, the instrument operates in, so called,
single phase mode
– see full-scale
Operating Manual
.
Connection of Measured Voltages – VOLTAGE Group of Terminals
Terminal
Type of connection
VOLTAGE
wye-star (3Y)
delta (3D)
Aron (3A)
U
1
L1-phase voltage
L1-phase voltage
L1-phase voltage
U
2
L2-phase voltage
L2-phase voltage
L2-phase voltage
U
3
L3-phase voltage
L3-phase voltage
L3-phase voltage
U
N
neutral wire voltage
-
-
In the case of indirect connection via the measuring voltage transformers, it is necessary to enter this matter ( connection
Mode
) and the values of the VT ratios during the
setup of the instrument.
The maximum cross section of the conductors to the terminal panels is 2.5 mm
2
.
1.2.3 Measured Currents
The instruments are designed for indirect current measurement via external CTs only. Proper current signal polarity (S1 & S2 terminals) must be observed. You can check the
polarity by the sign of phase active powers on the instrument display (in case of energy transfer direction is known, of course).
The CT-ratio must be set. in
the Installation
group of parameters (see below).
The I2 terminals stay free in case of the Aron (A) connection.
To get better precision when using overweighted CTs, you can apply more windings of measured wire through the transformer. Then you must set the multiplier
parameter (see below). For standard connection with 1 winding, the multiplier must be set to 1.
