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www.kraftpowercon.com
6.4.4.4
Blocking of earth fault measuring/battery test
This input is only used in the case of “Double systems” (see section
4.4.4). The input has different
functions depending on the sub-system it is included in.
Sub-system A:
Open condition signals that both sub-systems are connected. This means, among other things, that
earth fault measurement in sub-system A is disconnected, as two earth fault meters would interfere
with each other.
Sub-system B:
Closed condition signals that the voltage is to be lowered to test level as sub-system A has started a
battery circuit test. This input is connected to output “BATT.TEST” in sub-system A (see section
6.4.5.4).
Connect to input X9:7-8 “E.F. BLOCKED (batt.test)”.
6.4.4.5
External faults
The “EXT. FAULT” input is intended for monitoring external units. Alternative alarm texts can be
selected. As a special case, you can use the input for remote controlled shutting down of the
rectifier. For more information, see section
5.13.10.
Connect to input X9:9-10 “EXT. FAULT”.
6.4.5
Digital outputs
6.4.5.1
General
All outputs fitted with relays have floating relay contacts. For the durability of the relay contacts,
see section
3
TECHNICAL DATA
.
6.4.5.2
Alarm outputs
There are four regular alarm outputs, alarm relays A - D.
The outputs' connection blocks are marked C, NC and NO. The significance of this is as follows:
• C
-
Common point for connection.
• NC -
Connection point for normally closed contacts. Closes on alarm.
• NO -
Connection point for normally open contacts. Opens on alarm.
The term “normal” (N) here means resting relays, i.e. idle. We recommend using NO mode. This
increases reliability as any poor contact action or other breaks in the alarm loop give an alarm
indication. To increase reliability still further, all alarm relays have standing current connection,
i.e. closed relay indicates normal condition while a relay that is idle gives an alarm. This means,
for example, that even a broken relay or the absence of auxiliary voltage gives an alarm indication.
Connect the alarm relays as follows:
Alarm relay A: C ............. Terminal X6:1
NO .......... Terminal X6:2
NC .......... Terminal X6:3
Alarm relay B: C ............. Terminal X6:4
NO .......... Terminal X6:5
NC .......... Terminal X6:6
Alarm relay C: C ............. TerminalX6:7
NO .......... Terminal X6:8
