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7
Maintenance
7.1
Meter Testing
7.1.1
Test Mode
7.1.2
Measuring Times
© Landis+Gyr AG
This chapter describes the necessary maintenance work.
Meter tests should be performed at periodic intervals according to the valid
national regulations (either on all meters or on specific random samples). In
principle, the meters should be de-installed for this purpose according to
the instructions in section 4.7 "De-Installation" and replaced by a substitute
meter. The meter test can also be performed on the spot in certain circum-
stances.
The test mode permits increasing the resolution of the energy registers by 1
to 5 digits. This allows the energy supply company to carry out the so called
measuring unit test in a reasonably short time.
In test mode, the same registers shown as a rolling list in the operating
display are always displayed, but with high resolution and not rolling.
The energy registers comprise a total of 12 digits. A maximum of 8 digits,
however, is shown on the display. The effective number of digits shown and
the number of decimal places are determined by the parameterisation. For
the test mode more decimal places are normally parameterised (maximum
5) to permit a quicker test of the transmission to the energy registers.
Display changeover normal mode – test mode
Fig. 7.1
Changeover from normal to test mode and back is made by formatted
commands (see section 5.8 "Input of Formatted Commands") or manually
in the service menu.
In test mode, the optical test output for active energy can also provide reac-
tive energy pulses depending on the parameterisation. Reactive energy
pulses are supplied to this test output if the register shown on the display
represents a reactive energy register. Active energy pulses are supplied for
all other measured values shown as in normal operating mode. Formatted
commands can also be used to define whether the optical test output for
active energy in test mode should supply active or reactive energy pulses,
independent of the type of register shown on the display. This permits
changeover without manual intervention.
For technical reasons, greater measuring deviations can occur during
short-term measurements. It is therefore recommended to use sufficiently
long measuring times in order to achieve the required accuracy.
D000030110 d – E650 Series 3 (ZMD400AT/CT, ZFD400AT/CT) – User Manual
Maintenance
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