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Universal Measuring Device UMG 500A
Universal Measuring Device UMG 500A is suited for
fixed front panel mounting and to meaure voltage, current,
power etc. in low voltage distributions. Current measure-
ment is performed via external current transformers with
5 A secondary (1 A optional). Voltage within the given
measuring range can be connected directly to the device.
Compared with individual analogue measuring instru-
ments, the Universal Measuring Device has the advantage
of requiring considerably less mechanical content and
wiring content. Stocking is easier, because with the
Universal Measuring Device UMG 500A, practically all
standard measurement ranges in low voltage installations
can be achieved.
Applications include:
- monitoring and control of electrical parameters
in energy distribution systems
- sensor in building wiring systems
The following measured values can be called up:
• voltage
• current
• mean current
• apparent power
• real power
• mean real power
• reactive power
• frequency of voltage
• harmonic wave content of voltage
• power factor
• peak values with date and time *1)
• real work
• reactive work
Outputs:
• analogue output
• threshold contacts
• serial interface (designed for networking)
Application
*1) Peak values of harmonics are stored without date and
time.
Construction features
Universal Measuring Device UMG 500A is housed in a
144 mm x 144 mm plastic case suitable for front panels
mounting.
Operation and programming are achieved via a membrane
keyboard and four-digit display with 20 mm characters.
The auxiliary voltage, measurement inputs etc. are con-
nected at the rear panel via protective plug terminals.
Functional description
The three phase electronic measuring system measures
and digitizes the effective value of voltages and currents in
a 50 Hz or 60 Hz power supply. Every 2 seconds, a
sampling measurement is carried out. By means of these
measurements, the built-in microprocessor computes the
electrical values. The desired values can be displayed on
keystroke, the dimensions of the values being indicated by
the relevant LED.
Peak values and programming data are stored in a battery-
supplied memory.
Warning note
In case of three-wire connection, the measuring
part is configured as an “Aron”- connection. Due to
this, current in L2 will be ignored for power meas-
urement.
For this reason, the results of the following func-
tions:
P, Q, S, power factor, W, and B
are valid only as the sum. The real power is calcu-
lated as follows:
P
Σ
= P1 + P3
