The function can be enabled and disabled with the Operation setting. The corresponding parameter values are "On" and "Off".
The operation of TRPPTRC can be described with a module diagram. All the modules in the diagram are explained in the next sections.
Timer
The duration of the TRIP output signal from TRPPTRC can be adjusted with the Trip pulse time setting when the "Non-latched" operation mode is used. The pulse length should be long enough to secure the opening of the breaker. For three-pole tripping, TRPPTRC has a single input OPERATE, through which all trip output signals are routed from the protection functions within the protection relay, or from external protection functions via one or more of the protection relay's binary inputs. The function has a single trip output TRIP for connecting the function to one or more of the protection relay's binary outputs, and also to other functions within the protection relay requiring this signal.
The BLOCK input blocks the TRIP output and resets the timer.
Lockout logic
TRPPTRC is provided with possibilities to activate a lockout. When activated, the lockout can be manually reset after checking the primary fault by activating the RST_LKOUT input or from the LHMI clear menu parameter. When using the "Latched" mode, the resetting of the TRIP output can be done similarly as when using the "Lockout" mode. It is also possible to reset the "Latched" mode remotely through a separate communication parameter.
The CL_LKOUT and TRIP outputs can be blocked with the BLOCK input.
| Mode | Operation |
|---|---|
| Non-latched | The Trip pulse time parameter gives the minimum pulse length for TRIP |
| Latched | TRIP is latched ; both local and remote clearing is possible. |
| Lockout | TRIP is locked and can be cleared only locally via menu or the RST_LKOUT input. |