Siemens 3TK28, Руководство пользователя

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Description of the individual safety relays
3.6 3TK28 safety relays with relay enabling circuits
3TK28 safety relays
Manual, 07/2016, NEB926157502000/RS-AB/003
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3.6 3TK28 safety relays with relay enabling circuits
3.6.1 3TK2810-0 safety relay
3.6.1.1 Applications
Applications of the 3TK2810-0 safety relay
You can use the 3TK2810-0 safety relays for safety standstill detection on 3-phase and
1-phase induction motors, e.g. to disengage protective door release mechanisms on
machine tools or to activate stopping brakes.
3.6.1.2 Description of function and connection information
The 3TK2810-0 safe standstill monitor measures a voltage of the coasting motor induced by
remanent magnetization at 3 terminals of the stator winding.
If the induction voltage approaches 0, this means motor standstill for the device and the
output relay is activated.
To enable adaptation of the device to the most varied types of motors and applications, the
voltage threshold U
an
, below which the 3TK2810-0 detects standstill, can be set. The
duration for which U
an
must be undershot to detect standstill definitively and enable the
output circuit can also be set (standstill time t
s
).
The device also detects wire break between the measurement inputs L1 / L2 / L3. If a wire
break is detected, the output relay goes into the safe position (as it does when the motor is
running). This state is stored and can be cleared by (briefly) jumpering terminals X2 - X3. X1
- X2: Feedback circuit for connecting external contactors (NC contact). If the feedback circuit
is not required, terminals X1 - X2 must be jumpered; otherwise a fault will be signaled.
WARNING
Hazardous voltage!
Can cause electric shock and burns.
The control terminals X1 / X2 / X3 are not electrically isolated from the measurement inputs
L1 / L2 /L3.
For this reason only use floating contacts for the control terminals.