Siemens 7UT51 Instruction Manual page 125

Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators
7UT51 v3
Trip Contacts
„
„
Figure 13.4 Trip Contacts
To second Trip Contact
Trip Relay
Coil
Constant current source
with Field effect Transistors
Figure 13.5 Trip Contact Monitoring Circuit
PRIM-2330C
Each signal contact is controlled
by up to 20 events.
For example:
„ 0511 General Trip of the Relay
„
1571 49-1 Thermal Overload Trip
„ 1621 49-2 Thermal Overload Trip
„ 2451 Backup Overcurrent Trip
„ 4537 External Event 1 Trip
„ 5673 87 Diff Trip Phase B
„ 5691 87 Diff Trip
„ 5821 87N RGF Trip
„ 5921 64T Tank Trip
Use to...
„
Trip circuit breakers
TR
T1
Trip
Contact
T2
TCML:
Trip Circuit Monitoring Logic
Event 1
Event 2
:
:
Event 20
7UT512:
7UT513:
Make Capacity:
Break Capacity:
Switching Voltage:
Permissible Current:
• One Trip Contact is controlled by two
Transistors (T1 & T2)
• For a pair of Trip Contacts, there is an
additional Release Transistor (TR)
• During normal operation, a trip contact is
inactive. If all Transistors are healthy (high
resistance), a low current will flow over the
TCML
opto-coupler Diodes and the Trip-contact-coil.
• If a Transistor is switched on, the opto-coupler
will be inactive.
• Sequentially, each Transistor can be switched
on and off, to test the status of the transistor
and the opto-coupler
• In case of Trip-command, all Transistors are
switched on.
• The status of the Trip Transistors and the trip
coil is monitored continuously.
2 0
3 2
1000 W/VA
30 W/VA
250 V
5 A continuous
30 A for 0.5 s
13
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