DEMA CPM 311, User Manual

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ON THE USE OF APPLICATION DIAGRAMS
The cabling of CPM 311 varies by the application. All applications need the
Fundamental Cabling
Diagram,
given at p.192; however, protection applications on power transformers, motors or overhead
lines requiring different schemes and functions will need numerous types of additional application
diagrams.
Application diagrams that may be required to realize these various protection applications are given on
the following pages. Appropriate diagrams can be selected and merged to form a master diagram; by
using this modular method, it should be easier to derive any desired diagrams suitable for a given
application. Utilize the
Use of Application Diagrams With Respect to Functions table given at p.191 to
form your own master diagram.
SAMPLE APPLICATION
It is required that, the protection and alarming system of an oil-immersed type power transformer
with characte
ristics 2,500 kV·A, 34.5 kV / 0.4 kV, 50 Hz is to be done, using DEMA CPM 311.
Protection current transformers are selected as type 5 V·A, 5P20, (60/5 ) A 6 . System must be
configured so that the CB control can be done via relay menus, CB position indication is monitored on
the relay; additionally, it must be alarmed by means of an acoustic announcing system if by any
reason the relay is out of service or auxiliary supply failure occurs.
To create a master diagram that fulfills these requirements,
Use of Application Diagrams With Respect
to Functions
table has been utilized and the following information has been acquired:
• Like for any application,
Fundamental Cabling Diagram
must be used.
• To provide CB control and position monitoring via CPM 310, Application Diagram No.3 is needed.
•
Protection and alarm contacts existing on a 2500 kV·A, 34.5 kV / 0.4 kV power transformer is
listed below.
o
Buchholz Alarm,
o
Buchholz Trip,
o
Thermometer Alarm,
o
Thermometer Trip,
To monitor and evaluate signals from these contacts,
Application Diagram No.5
will be used.
• To notify the operator by means of an acoustic announcing system if the protection system
generates an alarm signal or trip, Application Diagram No.7 should be applied. For the alarm / trip
announcing circuit on this example, DEMA WR25 Pulse Relay, KR30 Horn Relay and K 101 – A2
Horn with U
aux
= 24 V
DC
are used.
• To notify the operator by means of an acoustic announcing system if by any reason the relay is
out of service or auxiliary supply failure occurs,
Application Diagram No.2
should be applied. For
the DC Fault announcing circuit on this example, DEMA WR25 Pulse Relay, KR30 Horn Relay and K
101 – A2 Horn with U
aux
= 220 V
AC
are used.
The master diagram will be formed by merging:
• Fundamental Cabling Diagram,
•
Application Diagram No
.2,
•
Application Diagram No
.5,
•
Application Diagram No
.6,
•
Application Diagram No
.7.
Master diagram that fulfills the requirements of the project is formed and given at p.186.
□
6
The rated secondary complex power of CTs are evaluated taking actual secondary burden into consideration.
Please note that secondary burden consists of secondary cabling and devices.