Siemens SIMOCODE pro C, System Manual

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Overview of functions
5.2 Monitoring functions
SIMOCODE pro
System Manual, 05/2019, A5E40507475002A/RS-AD/004
49
5.2 Monitoring functions
Detailed description: See Chapters "Monitoring functions" and "Logic blocks" in the manual
Parameterizing SIMOCODE pro
( https://support.industry.siemens.com/cs/ww/en/view/109743958 ).
Current limit monitoring
Current limit monitoring is used for process monitoring. This enables incipient anomalies in
the system to be detected in good time. If a current limit is exceeded but still below the
overload limit, it can, for example, indicate a dirty filter on a pump, or an increasingly
sluggish motor bearing. If the current limit is undershot, it can be the first sign of a worn-out
drive motor belt.
Ground-fault monitoring
Residual current monitoring relays are used in industry to
● Protect systems from damage caused by residual currents
● Prevent production losses caused by unplanned downtime
● Perform maintenance to meet all demands.
Basic units have:
● An internal ground-fault monitoring system: For motors with a 3-wire connection, the
basic unit calculates a possible fault current/ground-fault current from the total current via
a current measuring module or a current / voltage measuring module. Internal
ground-fault monitoring is only possible for motors with a 3-phase connection in networks
that are either grounded directly or grounded with low impedance.
● External ground-fault monitoring in SIMOCODE pro S and SIMOCODE pro V
4)
: The
external ground-fault monitoring using residual current transformer 3UL23 and
ground-fault module is normally used in the following cases:
–
in cases in which power systems are grounded with high impedance
– in cases, in which precise detection of the ground-fault current is necessary, for
example, for condition monitoring.
A ground-fault module can be used to create an additional input on the
SIMOCODE pro V and SIMOCODE pro V PN GP basic units to connect a 3UL23 residual
current transformer.
A multifunction module can be used to create an additional input on the
SIMOCODE pro S basic unit to connect a 3UL23 residual current transformer.
With ground-fault detection using the 3UL23 residual current transformer, it is possible to
determine the precise residual current as a measured value, and to define freely
selectable warning and trip limits in a wide range from 30 mA - 40 A.
See also Chapter "External ground-fault monitoring with 3UL23 residual current
transformer" in the manual Parameterizing SIMOCODE pro
( https://support.industry.siemens.com/cs/ww/en/view/109743958 ).