Basler BE1-CDS220, Instruction Manual

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BE1-CDS220 Application 8-21
State Labels
Output Purpose Description Label
True False
VO15
Optional. Use to annunciate
an alarm when alarm point
23 is enabled.
VO15 is TRUE when IN8 is TRUE. IN8-ALARM ACTIVE NORMAL
BESTlogic Expression: VO15=IN8
TRANSFORMER WITH BACKUP SCHEME
The Transformer with Backup (TX-W-BU) scheme was designed to provide high-speed phase and ground
fault protection for a two-winding transformer and definite time backup protection for the associated low-
side bus (similar to the BE1-851 BUS and BACKUP Logic Scheme). Figure 8-7 shows the interconnection
of the BE1-851 or BE1-951 relays providing bus and feeder protection with a BE1-CDS220 (TX-W-BU)
providing backup transformer protection. The TX-W-BU scheme also includes a low-side breaker BF
(breaker failure) protection element with fast current reset. Current and contact supervised external
breaker failure initiates (BFI) are included for the low-side breaker BF element. Virtual control switch logic
is used for local or remote (SCADA) control and can be used to replace the equivalent panel control
switch. See the paragraphs on BUS WITH BACKUP SCHEME, in this Section for an interconnection of
BE1-851 or BE1-951 relays providing feeder protection with BE1-CDS220 relays providing bus protection
(BUS-W-BU) and transformer protection (TX-W-BU).
The control switch elements are referred to as virtual because they have no physical form, they exist only
in logic form, and they can only be operated via the ASCII command interface or the front panel HMI. The
virtual 101 switch is used to trip and close the transformer low-side breaker, and 743 is used to select test
mode enable. The user may choose to eliminate the use of external switches, as the virtual switches are
fully functional equivalents of their physical counterparts.
Figure 8-8 is a one-line drawing and Figure 8-9 is a logic drawing that represent the logic settings and
equations shown in Table 8-16. In Table 8-16, the user can see the protection and control elements that
are enabled for the TX-W-BU application and how the elements are logically wired together (equations). If
the user should decide to build on this scheme, all elements required for a more detailed application are
available through programming. For programming details, refer to Section 7, BESTlogic Programmable
Logic.
Table 8-16. TX-W-BU Logic Settings and Equations
SL-N=TX-W-BU
SL-87=1,43
SL-87ND=0,0
SL-50TP=2,0; SL-50TN=2,0; SL-50TQ=2,0
SL-150TP=0,0; SL-150TN=0,0; SL-150TQ=0,0
SL-250TP=2,0; SL-250TN=2,0; SL-250TQ=2,0
SL-51P=0,0; SL-51N=G,0; SL-51Q=0,0
SL-151P=1,0; SL-151N=1,0; SL-151Q=1,0
SL-251P=2,0; SL-251N=2,0; SL-251Q=2,0
SL-62=1,VO9,VO15
SL-162=0,0,0
SL-BF=2,VO10,VO15
SL-GROUP=2,/IN5,0,0,0,0
SL-43=2
SL-143=0
SL-243=0
SL-343=0
SL-443=0
SL-543=0