Page 4
= Peak value
= Minimum value
= Supply
Product description
Intended use
The UMG96 is suited for fixed mounting and the measurement of voltage, current, power etc. in low voltage
switchgear. The measurement is designed for 3 phase systems with neutral conductor (TN and TT-mains).
Measurement and supply voltages (50Hz/60Hz) up to 275VAC against earth and 476VAC phase to phase can
be connected directly. The measurement and supply voltages must be connected to the UMG 96 via a separation
(switch or power switch) and an overcurrent protection fuse (2-10A) in the building installation. The connection
of the measurement and supply voltage is carried out on the back side of the UMG 96 via spring power
clamps, which are all-insulated. To the current measuring inputs, either ../5A or ../1A current transformers can
be connected.
Hints for the user
This device may be installed and used by qualified personnel only, according to the safety regulations. Please
mention the legal and safety regulations for the corresponding application, while using the device.
Qualified personnel are persons, who are familiar to installation, mounting, putting into service and operation
of the product and have qualifications according to their occupation, for example:
• Education or instruction or the right to switch on or off, ground or characterize current circuits or devices
according to the standards of safety techniques.
• Education or instruction in care and use of safety equipment according to the standard safety techniques.
Functional description
The electronical three phase measurement system determines and digitalizes the effective values of voltages
and currents in 50/60 Hz netenergys.
The auxiliary voltage needed for operation of UMG 96 is taken from the measurement voltages L1-N, L2-N
and L3-N. For devices for measurement in 230V/400V netenergys, at least one phase must be within the rated
voltage range. For devices measuring in 58V/100V or 63V/110V netenergys, at least two phases must be in
the rated voltage range.
For each random test one period is scanned. From those sampled values the microprocessor calculates the
electric magnitudes. These measured values are indicated within the programmable display. The programming
data and the minimum and maximum values are saved all 15 minutes in a none volatile storage (EEPROM).
The transistor outputs K1 and K2 can be used as switching or pulse outputs. The scanning frequency is
calculated for all measuring inputs from the net frequency of phase one. For a net frequency of 50Hz the
scanning frequency is 2,5kHz and for 60Hz it is 3,0kHz. If the voltage in L1 is smaller than 50V, the UMG 96
uses the last measured net frequency for the determination of the scanning frequency.
In order to achieve a constant quality while reading the display over the whole temperature range, the inner
temperature is measured and the contrast is changed automatically.
Attention!
There is no possibility for a measurement in systems with pulsed measurement signals, as no continous
scanning of the measurement signals is carried out.
