Electronic Control Box
10
•
TAny condition required to determine whether a supply source is or is not suitable is
determined by the user through the
P0
menu (system nominal data) and the
P2
and
P3
menus (voltage control, main line and secondary line, respectively).
•
It is possible to set up the system nominal data, such as nominal voltage and frequency,
through the
P0
menu, which will be used as a reference for setting up the percentage
thresholds of the following menus.
•
It is possible to set up a TV transformation ratio in case a lower voltage, relative to the
actual voltage of the system, is applied to the voltage inputs of the unit. Here, again, the
display and the setup of the thresholds will be executed in actual sizes referred to the
system.
•
The electronic control box can be programmed to perform voltage controls on three-
phase, two-phase or single-phase nets (via the
P0.03
parameter).
The following describes the anomalies monitored by the voltage control.
Columns M7000CB and M7000CB/EVO point out the presence of the function within their
unit models.
Control
M7000CB M7000CB/EVO Description
Minimum voltage
•
•
One or more phases too low
Maximum voltage
•
One or more phases too high
Phase failure
•
•
Threshold under which the device can
operate faster compared to a normal
reduction
Asymmetry
(unbalance)
•
Phases included in the Maximum-Minimum
interval, yet too different between each other
Minimum frequency
•
Frequency too low
Maximum frequency
•
Frequency too high
Sequence of phases
•
Reverse rotation of phases
•
Each anomaly has an independent delay time. The anomaly must last consecutively longer
than the time specified for invalidating the voltage presence signal.
•
All controls, except for the minimum voltage control, can be excluded separately by
setting the related parameter to OFF.
•
The minimum and maximum voltage limits are specified by setting up two thresholds
each, one which determines the point beyond which the voltage is no longer considered
acceptable (e.g. P2.01) and the other, closer to the nominal voltage, which determines
the point in which it becomes compatible again (e.g. P2.02). The distance between
these two thresholds determines the hysteresis. For instance, it may be considered
that when the nominal value is below 80%, the voltage may no longer be useable and
that in order to be considered useful, it must rise over 85%, thereby determining a 5%
hysteresis.
The same concept applies to the maximum voltage.
•
As for the frequency thresholds, there is a fixed 1% hysteresis of the nominal frequency.
•
The retrieval after a phase failure occurs when the voltage rises above the minimum
voltage retrieval threshold.
Example of variation of the main
line voltage within the mini-
mum and maximum thresholds
and relative hystereses, with
indication of the presence /
absence delay times. The ex-
ample considers the second-
ary line voltage absent with its
circuit breaker open, hence
the changeover times are not
shown. The INTERR. bar repre-
sents the required status of the
main line switch.
6. Voltage controls
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Summary of Contents for M7000CB
Page 1: ...Electronic Control Box item M7000CB item M7000CB EVO Part Y1791C 10 08 01 PC ...
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