Areva MiCOM P521 - APPLICATION GUIDE (P521_EN_AP_B11); MiCOM P521 trip circuit supervision mechanism

P521/EN AD/B21 Update Documentation
Page 14/24 MiCOM P521
APPLICATION GUIDE (P521/EN AP/B11)
3.8.1 MiCOM P521 trip circuit supervision mechanism
The Trip Circuit Supervision function included in the MiCOM P521 relay is performed
as follows:
A logic input can be programmed in the AUTOMAT.CTRL / Inputs/ Input #/Trip
Circ
menu. This logic input must be inserted in the trip circuit according to one of the
typical application diagrams, shown later.
When the function TC Supervision is enabled by selecting ‘Yes’ within the
AUTOMAT.CTRL/CB Supervision sub-menu, the relay continuously checks the trip
circuit continuity whatever the CB status – opened CB or closed CB. This function is
enabled when the trip output contact (relay RL1) is not energised and it is disabled as
long as the trip output contact is operating.
A “TRIP CIRCUIT” alarm signal (trip circuit failure) is generated if the opto-input
detects no voltage signal for a time longer than the settable timer tSUP
(AUTOMAT.CTRL / CB Supervision) . The “52 Fail” contact can be selectively closed
in the event of a trip coil failure.
As the TC supervision function is disabled when the trip output contact is operating,
this function is suitable for use with the product latching logic on.
The following table shows the setting associated with the trip circuit supervision
function:
Setting Range
Menu
Min Max
Step
TC Supervision ?
Yes No
tSUP 100ms 10s 50ms
P0037ENb
Logic input
Trip Circ.
Tripping
Relay RL1
Energized
tSUP 0
&
52 FAIL
Signal
Figure 21: Trip circuit supervision logic diagram
Three application examples are shown below.
Example 1
In this example only the 52a auxiliary contact is available, the MiCOM P521 relay
monitors the trip coil whatever the CB status (CB open or CB closed ). However, in
this example the relay does not supervise the trip circuit prior to the trip contact.