Siemens 6MD85, Manual

Page: 231 / 1256

The Circuit-breaker function block activates the device contact and thus causes the circuit breaker to open
(see
5.6.5.1 Overview ). The command output time is also effective here. In the trip logic, the decision is made
whether to trigger 1-pole tripping or not (3-pole coupling) (see Figure 5-34 ).
The trip logic also decides when the protection trip command is terminated (see Figure 5-35 ).
[loausl1p-070211-01.tif, 1, en_US]
Figure 5-34 1-Pole or 3-Pole Operate and 3-Pole Coupling
1-Pole or 3-Pole Operate
Under certain circumstances, the device can cause 1-pole operate in the event of 1-phase or 2-phase faults.
The device always causes 3-pole operate in the event of 3-phase short circuits.
The preconditions for 1-pole operate are:
•
The device is designed for 1-pole operate (see Order reference).
•
The tripping protection function can generate 1-pole operate indications and is set accordingly (
1-pole
operate allowed
parameter set to
yes
).
•
The circuit-breaker function group allows 1-pole operate.
To do this, set the
1-pole operate allowed
parameter in the circuit-breaker function group (see
General parameters of the function group) to
yes
.
•
The Automatic reclosing function is active and generates the
79 permits 1-pole trip
signal. The
function thus indicates that it is healthy for 1-pole reclosing after 1-pole operate.
Function-Group Types
5.6 Function-Group Type Circuit Breaker, 1-/3-Pole
SIPROTEC 5, High-Voltage Bay Controller, Manual 231
C53000-G5040-C015-9, Edition 11.2017