SMY133-SMY134-SMP133 Operating Manual
3. Commissioning
3.1 Setup
When switching on the power supply, the instrument will display manufacturer's logo for short time and
after that, one of actual data screen - for example the line-to-neutral voltages one - is displayed :
At this moment it is necessary to set
instrument parameters
that are essential for proper instrument
measurement (so called
Installation
group) :
•
mode of connection ( direct measuring or via metering voltage transformers )
•
type of connection ( star, delta, Aron )
•
ratio of CTs, VTs and their multipliers (if used)
•
nominal voltage
U
NOM
and nominal frequency
f
NOM
•
I
NOM
,
P
NOM
(not mandatory, but recommended)
3.1.1 Measured Electrical Quantities Installation Setup
For the proper data evaluation it is necessary to set all of the
Installation Setting
group
parameters.
•
Connection Mode
determines if voltage signals are connected directly or if voltage
transformers are used.
•
Connection Type
needs to be set according network configuration – wye (or star,
Y
) or
delta (
D
, if neutral voltage potential not connected ). Usually, all of three phases are
connected so choose
3-Y
or
3-D
. For Aron connection set
3-A
. For single-phase connection,
set
1-Y
.
•
CT (CT
N
, CT
RCM
)
- ratios must be specified, in case of “
via VT
” connection mode
VT
-ratio too.
The
CT
is valid for currents I1, I2 and I3. If the fourth current input or residual current inputs
are used, appropriate ratios
CT
N
/
CT
RCM
must be set too.
CT ratios can be set in form either …/ 5A or …/ 1A or …/ 333mV.
The
VT
-ratio must be set in form
Nominal primary voltage / Nominal secondary voltage
. For
higher primary voltage values
the U-multiplier
must be used too.
•
I-
and
U-Multipliers
- You can modify any CT- / VT-ratio with this parameters. For example,
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. For example, for 2
windings applied, set the multiplier to 1/2 = 0.5 .
For standard connection with 1 winding, the multiplier must be set to 1.
The
CT
N
and
CT
RCM
ratios have their extra
I
N
–
and
I
RCM
–Multipliers
.
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