MC20-CEI
Doc. N°
MO-0431-ING
Microelettrica Scientifica S.p.A. - Copyright 2009
FW 1080.36.03.X
Date 18.11.2011
Rev.
3
Pag. 19
of 35
6. Digital Inputs
Three optoisolated, self-powered Digital Inputs are provided.
A Digital Input is activated when its terminals are shorted by a cold contact.
D1
(Terminals 22 - 19)
:
Functions Blocking Input
It is used to blocking the programmed functions (“
BI
” Parameter)
D2
(Terminals 22 - 21)
:
Input the condition Circuit Breaker OPEN (52a)
(
Input Closed
= C/B open;
Input Open
= C/B closed).
D3
(Terminals 22 - 20)
: Input the condition Circuit Breaker CLOSE (52c)
(
Input Closed
= C/B closed;
Input Open
= C/B open).
7. Self-diagnostic
The relay incorporates a sophisticated self-diagnostic feature that continuously checks the following elements:
A/D conversion
Checksum of the settings stored into E
2
Prom.
DSP general operation (Power, Routines, etc.)
Lamp test (only on manual test).
Any time Power is switched on, a complete test is run; then, during normal operation, the test runs continuously
and the checksum is done any time a parameter is stored into E
2
Prom.
If during the test any Relay Internal Failure (
I.R.F
) is detected:
If “ I.R.F. “ is programmed to “ Trip “, the programmed output relays are operated same as on tripping of any
protection function
If set “
NoScatto
” (
NoTrip
), the trip of “
I.R.F.
” function is recorded in “
UltimiSc
” (
Last Trip
)
