PRELIMINARY
Output feeder monitor MEg71
Output feeder monitor
MEg71
Manufacturer
MEgA – Měřící Energetické Aparáty, a.s., 664 31 Česká 390, Czech Republic
tel. +420 545 214 988, e-mail: mega@e-mega.cz, www.e-mega.cz
Edition: 03/2013
Měřící Energetické Aparáty, a.s.
664 31 Česká 390
Czech Republic
Měřící Energetické Aparáty
CHARACTERISTICS
The output feeder monitor MEg71 is intended for measuring voltages, currents, powers
and energies of a LV output feeder of a switchgear with fuse rails or fuse disconnectors.
The monitor in the version MEg71D displays phase voltages, phase currents and active and
reactive powers of the feeder on an eight-character backlit LCD display.
The slim version of the monitor – MEg71S indicates voltages in/outside allowable tolerances
using LEDs U1, U2 and U3.
The outlet monitors MEg71 measure voltages and register voltage events using methods
defined in EN 61000-4-30, ed. 2 without interruptions and gaps.
The energy measurement is four-quadrant with six registers for each phase.
All measured and statistically processed values are transmitted through the RS485 communication interface and using the protocol MODBUS to a local or remote host system.
The parameterization and on-line measurement can be performed on PC with the program
MERCI, the measured data files can be browsed and evaluated using the browser program
DVMEG and the program WebDatOr is used for data saved in a database.
The monitor MEg71 consists mechanically of two constructionally separated parts,
a measuring unit and a measuring rail with sensors. The sensors contain current transformers
with integrated protections in case that the secondary circuit is open and a contact with
front-end resistances for measuring voltages. The measuring rail with the height of about
20 mm is to be installed between the fuse rail and busbars of the LV switchgear case.
The output feeder monitor MEg71 has an internal backup clock and a data memory for
storing statistically evaluated data. The processor of the monitor MEg71 reads and processes
also the signal of LV fuse interruption and the signal of opening the draw bar of the fuse
disconnector. The rated value of the used LV fuses is preset accessibly on the measuring rail
and then processed by the processor during evaluation.
The measuring units in both versions can be moved between the individual rails also during
operation. In this way, one unit can be used for successive measurements on more LV
feeders. Before it is disconnected from one rail, it is necessary to read the measured data
from the unit. After the unit is connected to another rail, the measuring current range is
changed automatically according to the rated value of the LV fuses used in this rail.
The low height of the measuring rail allows additional installation of the monitor MEg71 into
already operated LV switchgear cases with fuse rails and fuse disconnectors.
Output feeder monitor MEg71
Measured quantities:
Voltage U, direct measurement, CAT IV
Unom = 230 VAC
Measurement uncertainty of U:
Measuring range of U:
Current I, direct measurement, CAT IV
Inom = from 10 A to 1600 A,
(according to the rated value of fuses set on the connector of the measuring rail)
Measurement uncertainty of I:
0.5 % of measured value ± 0.2 % Inom
Measuring range of I:
0.05 Inom to 10 Inom
Active power P
Measurement uncertainty of P:
0.5 % of measured value ± 0.5 % Pnom
Reactive power Q
Measurement uncertainty of Q:
0.5 % of measured value ± 0.5% Qnom
Active energy Aact
Measurement uncertainty of Aact:
in accordance with class A according to EN 50470
Reactive energy Areact
Measurement uncertainty of Areact:
accuracy class 2 according to EN 62053-23
Voltage events, voltage deviations
Class S according to EN 61000-4-30, Ed. 2
General data:
Data memory:
Data memory organisation:
Serial interface:
Supply voltage:
Supply current:
Protection rating:
TECHNICAL PARAMETERS
Design details:
Working conditions:
Dimensions:
Operating temperature:
-25 °C to +60 °C
-25 °C to +100 °C
Relative humidity:
10 % – 90 % at 40 °C
measuring unit
measuring rail
0.1 % of measured value ± 0.1 % Unom
5 % – 120 % Unom
91 × 109 × 40 mm
91 × 109 × 16 mm
528 × 24 × 67.5 mm
2 × 4 MB – FLASH
linear or circular
RS485 / 115.2 kbit/sec
9 VDC – 16 VDC
up to 100 mA
IP20
measuring unit MEg71D, without frame
measuring unit MEg71S, without frame
measuring rail, hole diameter 12.5 mm
Maximum length of power and communication wires: 30 m