Overview Of Functions; Protection Functions; Monitoring Functions - Siemens SIMOCODE pro System Manual

1.5

Overview of functions

1.5.1

Protection functions

Detailed description: See
Overload protection
Current-dependent electronic protection of three-phase and AC motors with
adjustable tripping characteristics (class times) according to IEC 60947-4-1
requirements.
Unbalance protection
Protects motors from excessive temperatures caused by excessive phase
unbalance.
Stalled rotor protection
Immediate trip after the motor current overshoots an adjustable threshold.
Thermistor protection
The basic units (BU1 and BU2) enable connection of thermistor sensors
(binary PTC) for monitoring motor temperature.
1.5.2

Monitoring functions

Detailed description: See
"Logic modules"
Earth-fault monitoring
Basic units have
• Internal earth-fault monitoring:
For motors with a 3-wire connection, the basic unit calculates a possible fault
current/earth-fault current from the total current via a current measuring
module or a current/voltage measuring module. Internal earth-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 earth-fault monitoring for SIMOCODE pro V
In the case of networks that are grounded with a higher impedance it may be
necessary to set up the earth-fault monitoring for smaller earth-fault currents
using a summation current transformer, instead of carrying out internal earth-
fault monitoring via a current measuring module or current/voltage measuring
module. A maximum of one earth-fault module can be used to create an
additional input on basic unit 2 to connect a 3UL22 summation current
transformer. Rated fault currents of 0.3 A/ 0.5 A/ 1 A can be evaluated with
the summation current transformer.
Current limit monitoring
Current limit monitoring is used for process monitoring. Thus, impending
irregularities in the system can 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.
SIMOCODE pro
GWA 4NEB 631 6050-22 DS 03
Chapter 3 "Motor protection".
Chapter 5 "Monitoring functions"
System description
and Chapter 11
1) 5)
:
1-15