On The Use Of Application Diagrams - DEMA CPM 310 G User Manual

ON THE USE OF APPLICATION DIAGRAMS

The cabling of CPM 310 G varies by the application. All applications need the Fundamental Cabling Diagram,
given at p.193; 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.192 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
characteristics 2,500 kV·A, 34.5 kV / 0.4 kV, 50 Hz is to be done, using DEMA CPM 310 G. Protection current
transformers are selected as type 5 V·A, 5P20, (60/5)A
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

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 = 220 V are used.
aux AC
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.191. □
8
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.
8
. System must be configured so that the CB control can
- 190 -
= 24 V are used.
aux DC