Mega Meg39, Руководство пользователя, Страница: 20 / 32

Měřící Energetické Aparáty
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3. For indirect measurements at the MV and HV level, the measuring voltage inputs are
connected according to the wiring diagrams in Fig. 4 to Fig. 6 to the output terminals
of voltage instrument transformers.
For direct measurements at the LV level, the measuring voltage inputs are connected
to measured voltages at phases L1, L2 and L3 via the three-pole fuse disconnector
with fuses 2 A / 500 V, see in Fig. 7.
When measuring phase voltage of another, non power-connected branch of the LV
network by means of the measuring input U4 , it is necessary to insert a one-pole
fuse disconnector with a fuse between the
U4
input of the MEg39 monitor and the
measured voltage, see in Fig. 8.
4. When the fuse disconnector is switched „ON“, check the function of the LEDs
U1
,
U2 , U3 and U4 , which signalize the status of measured voltage at the corresponding
inputs.
Connecting measured currents
Connecting current circuits must be performed either with the power switched off or
with short-circuited secondary winding of the current instrument transformer.
All current inputs of the monitor MEg39 have the same value of rated current of either
1 A or 5 A, depending on an order.
The type and rated value of primary current of the current instrument transformer is
set by the user according to voltage level and required measured current at the place of
installation.
5. Currents indirectly measured by measuring instrument transformers are connected
via short-circuited current double terminals to the current inputs I1 , I2 , I3 and I4 ,
as the case may be, of the monitor MEg39 according to Fig. 4 to Fig. 8. The secon-
dary winding of the current transformer inserted in the L1 phase is connected to
the I1 input, The secondary winding of the current transformer inserted in the L2
phase is connected to the I2 input, The secondary winding of the current transformer
inserted in the L3 phase is connected to the
I3
input. Similar procedure is used for
connecting the current input I4, as necessary.