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17
Function library
17.1
Function blocks | L_MFail_1
1407
Lenze · 8400 HighLine · Reference manual · DMS 12.0 EN · 06/2017 · TD23
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17.1.102.1 Procedure of the mains failure control
A failure of the voltage supply of the power section can be detected by
• an evaluation of the DC-bus voltage
and/or
• an external monitoring system (e.g. voltage measuring relay).
The type of mains failure control to be used depends on the used drive system.
Evaluation of the DC-bus voltage
This proceeding is used for single drives or multi-axis drives which do not use an external
monitoring system.
• For evaluating the DC-bus voltage, you can use a comparator (e.g. FB
) as shown
in the following interconnection example 1.
• In order that the mains failure control will be activated if the DC-bus voltage falls below a
certain operating threshold, set the comparison function "2: In1 > In2" has to be set for the
FB
• For specifying the operating threshold, the SB
is used. This system block can
output 16 parameterisable analog signals. In the shown example, the operating threshold
has to be set in the "free parameter"
.
[17-43] Interconnection example 1: Evaluation of the DC-bus voltage with a comparator (cutout)
Use of an external monitoring system
In this proceeding, the digital status signal of an external monitoring system is connected to the
FB
L_MFail_1
via a digital input of the inverter.
• In the following example, the digital input DI7 is used.
• The active level (HIGH or LOW active) for DI7 has to be parameterised in
in such a way
that
bFault
becomes TRUE when the monitoring system is tripped.
• A free input of the application block can be used to transfer the digital input signal from I/O
level to application level.
[17-44] Interconnection example 2: Use of the digital status signal of an external monitoring system
Note!
The following interconnection examples are not functional yet. For an error-free
function, connect the FB
L_MFail_1
with further signals!
IO level:
Application level: