Siemens SIMATIC PCS 7 사용자 설명서

22

Monitoring and diagnostics of 
24 V load feeders

In the process industry, automation components are generally 
powered with 24 V DC. With the SITOP PSE 200U selectivity 
module, any 24 V load is reliably monitored for overload and 
short circuit and in the event of faults it is switched off. 

A selectivity module monitors up to 4 load feeders which can 
also be connected in sequence following defined periods in 
order to offload the power supply. Monitoring currents are ad-
justable between 0.5 to 3 A and 3 to 10 A.  The electronic sys-
tem allow short current spikes such as making current swit-
ching spikes, but longer-lasting overloads or short circuits are 
switched off.

If one of the four outputs is switched off, a sum signaling con-
tact is activated and can be evaluated by the higher-level au-
tomation system. The service technician recognizes on site 
which 24-V feeder is concerned, since each output has a mul-
ti-color LED to indicate the current operating status. Besides 
fast error detection and localization, this leads to a reduction 
of downtimes.

SITOP PSE200U selectivity module

Monitoring and diagnostics of wear 
in the motor and its vicinity

In the vicinity of motors, there are a number of wear fields: the 
power distribution, the motor feeder or converter, the motor 
itself, the supply lines, and the machine that the motor drives. 
For the user it is of great benefit if routine (visual) inspections 
by the servicing personnel, e.g. in order to determine the con-
dition of the main contacts of contactors, can be omitted and 
the device can diagnose its own condition.

Condition monitoring records the wear with the aid of measu-
red values which can be used to determine the condition of 
the affected components. Thus, depending on this condition, 
it is possible to determine the optimal time for maintenance. 

Continuous system monitoring allows for intelligent mainte-
nance with the optimized use of maintenance resources. For 
the motor environment, Siemens offers a series of condition 
monitoring-capable protective devices and switching devices.

Siemens protection and switching devices are
• Powerful products for industrial controls with comprehen-

sive basic functions and

• Information for condition monitoring.

In these devices, the data or acquisition variables needed for 
the basic functions are also used for condition monitoring or 
condition monitoring statements can be derived from this da-
ta. The devices also have additional analog inputs, to which 
special sensors for condition monitoring analyses can be con-
nected (example: SIMOCODE).

Only when a large number of measured values must be recor-
ded or they reach a very high degree of complexity, special de-
vices purely for the purpose of condition monitoring are nee-
ded for monitoring bearings or pumps, for example.

In addition to the condition monitoring capability of the de-
vices, they also have corresponding communication functions 
so that they can be optimally integrated into systems and 
plants. In addition, they are integrated in the Maintenance 
Station as follows:
• Via device ID IM0
• Via driver output for the control of the device condition sta-

tus

• Via detailed diagnostics of the device condition (device-

specific)

• For devices with an AS-Interface connection, the integra-

tion into the Maintenance Station takes place via suitable 
SIMATIC S7 communication processors (CPs) or AS-i links

Maintenance_PA_04_2010_en.book  Seite 22  Dienstag, 6. September 2011  9:45 09

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