3-8
Input and Output Functions
BE1-951
0.200 Sec
0 Sec
O R
O N E S H O T T I M E R
A N D
OUT[n]
H A R D W A R E
O U T P U T
O U T P U T
S T A T U S
A N D
A N D
O R
Control Override (0/1)
Override State (0/1)
Hold State (0/1)
VO[n]
V I R T U A L O U T P U T
C O N T R O L E D B Y S L - V O [ n ]
L O G I C E Q U A T I O N
H O L D E N A
( S G - H O L D C O M M A N D )
O U T P U T C O N T R O L
( C O - O U T C O M M A N D )
A N D
A L M R E L
D 2 6 4 7 - 1 8
08-20-98
Figure 3-2. Output Logic, General Purpose Output Contacts
0.200 Sec
0 Sec
O R
O N E S H O T T I M E R
A N D
OUT[A]
H A R D W A R E
O U T P U T
O U T P U T
S T A T U S
A N D
A N D
O R
Control Override (0/1)
Override State (0/1)
Hold State (0/1)
VO[A]
V I R T U A L O U T P U T
C O N T R O L E D B Y S L - V O [ n ]
L O G I C E Q U A T I O N
H O L D E N A
( S G - H O L D C O M M A N D )
O U T P U T C O N T R O L
( C O - O U T C O M M A N D )
A L M R E L
D 2 6 4 7 - 1 9
08-20-98
N O T
Figure 3-3. Output Logic, Fail-Safe Alarm Output Contact
Retrieving Output Status
Status of output contacts can be assessed at HMI screen 1.4.2 and through the communication ports using
the RG-STAT (report general-status) command. See Section 6,
Reporting and Alarm Functions, General
Status Reporting for more information.
Relay Trouble Alarm Disable
When the BE1-951 self-diagnostics function detects a relay problem, an internal alarm condition (ALMREL)
is set. This alarm condition disables the outputs and de-energizes the OUTA relay closing the OUTA
contact. For more details about this function see Section 6,
Reporting and Alarm Functions, Alarms
Function.
Programmable Hold Timer
Historically, electromechanical relays have provided trip contact seal-in circuits. These seal-in circuits
consisted of a dc coil in series with the relay trip contact and a seal-in contact in parallel with the trip contact.
The seal-in feature serves several purposes for electromechanical relays. One purpose is to provide
mechanical energy to drop the target. A second purpose is to carry the dc tripping current from the induction
disk contact which may not have significant closing torque for a low resistance connection. A third purpose
is to prevent the relay contact from dropping out until the current has been interrupted by the 52a contacts
in series with the trip coil. If the tripping contact opens before the dc current is interrupted, the contact may
be damaged. Of the three items, only item three is an issue for electronic relays like the BE1-951.
To prevent the output relay contacts from opening prematurely, a hold timer can hold the output contact
closed for a minimum of 200 milliseconds. If seal-in logic with feedback from the breaker position logic is
desired, the BESTlogic expression for the tripping output can be modified. This process is described in
Section 7,
BESTlogic Programmable Logic, Application Tips.
The hold timer can be enabled for each input using the SG-HOLD (setting general-hold) command. Hold
timer settings are shown in Table 3-4.
Содержание BE1-951
Страница 157: ...BESTlogic Programmable Logic BE1 951 7 2 Figure 7 1 BESTlogic Function Blocks Courtesy of NationalSwitchgear com...
Страница 238: ...BE1 951 Human Machine Interface 10 5 Figure 10 5 Metering Menu Branch Structure Courtesy of NationalSwitchgear com...
Страница 239: ...10 6 Human Machine Interface BE1 951 Figure 10 6 Reports Menu Branch Structure Courtesy of NationalSwitchgear com...
Страница 270: ...12 2 Installation BE1 951 Figure 12 1 BE1 951 S1 Case Dimensions Courtesy of NationalSwitchgear com...
Страница 274: ...12 6 Installation BE1 951 Figure 12 5 BE1 951 H1 Case Dimensions Courtesy of NationalSwitchgear com...
Страница 283: ...BE1 951 Installation 12 15 Figure 12 16 Typical AC Connections Courtesy of NationalSwitchgear com...
Страница 394: ...A 18 Appendix BE1 951 Figure A 14 Time Characteristic Curve B Very Inverse 99 1376 Courtesy of NationalSwitchgear com...
Страница 396: ...A 20 Appendix BE1 951 Figure A 16 Time Characteristic Curve G Long Inverse 99 1622 Courtesy of NationalSwitchgear com...
Страница 397: ...BE1 951 Appendix A 21 Figure A 17 46 Time Characteristic Curve Courtesy of NationalSwitchgear com...