Siemens SIMOCODE pro System Manual

Monitoring functions
SIMOCODE pro
GWA 4NEB 631 6050- 22 DS 03
5-11
5.4 Cos phi monitoring
Description
Cos phi monitoring monitors the load condition of inductive loads. The main
field of application is for asynchronous motors in 1-phase or 3-phase
networks with loads that fluctuate significantly. The power factor fluctuates
more than either the motor current or the active power does, particularly in
the low-end performance area of a motor. Therefore, power factor
monitoring is particularly suitable for distinguishing between non-load
operation and faults, e.g. a broken drive belt or drive shaft. If the set trip
level or warning level is undershot, a signal is generated or the motor is
switched off, depending upon the setting.
Fig. 5-5: "Cos Phi Monitoring" function block
Trip level, warning level
You can parameterize two different response levels (trip level/warning level)
for cos phi monitoring.
0 % = cos phi = 0.00
50 % = cos phi = 0.50
100 % = cos phi = 1.00
Trip level: 0 - 100 %
Warning level: 0
- 100 %
Trip level
Response
Delay
Warning level
Response
Delay
Event
See
Ta b l e 5 - 9
See
Ta b l e 5 - 10
Cos phi monitoring
- Trip level cos phi <
Event
- Warning level cos phi <
Tripping
QE1
QE2
QE3
QE4
QE5
Cos phi from
Current/voltage
measuring module
Hysteresis
1)
1)
Hysteresis for voltage, cos phi, power
(see "Voltage Monitoring" function block)

Siemens SIMOCODE pro Specifications

General

Brand	Siemens
Model	SIMOCODE pro
Category	Control Unit
Language	English