pplication Notes
P74x/EN AP/N
1, P742, P743 (AP) 6-
9. IDN>1 (from 5 A to 500 A (primary value)), recommendation is equal to ID>1
10. Slope kN1 (IDN>1) (from 0% to 50%), recommendation is 5%.
11. IDN>2 (from 50 A to 50000 A (primary value)) as high as possible
12. Slope kN2 (IDN>2) (from 0% to 50%), recommendation is over 30%.
13. IDNCZ>2 (from 50 A to 50000 A (primary value)) as high as possible
14. Slope kNCZ (IDNCZ>2) (from 0% to 50%), recommendation is 10%.
15. IDN>1 Alarm Timer (from 0 to 100 s) recommendation = ID>1 Alarm Timer
2.1.1.4 Protection options for the Zones
2.1.1.4.1 Options for a Circuitry Fault
When something happens on the primary equipments that creates a small differential current
in a Zone such as CT short-circuited or a closed isolator “seen” open etc…, it is detected by
the Central Unit.
To avoid maloperation in case of through fault during a circuitry fault, there has been 3
options:
1. Blocking Latched
An alarm is provided and this alarm can only be reset manually,
The zone is blocked and this blocking can only be reset manually.
2. Alarm Latched
An alarm is provided and this alarm can only be reset manually,
The zone is blocked and this blocking will be automatically reset once the differential
current will disappear and after the set reset timer.
3. Self-Reset
An alarm is provided and this alarm can only be reset manually,
The zone is blocked and this blocking will be automatically reset once the differential
current will disappear and after the set reset timer.
From software E1.0, model 50, it exists the possibility to allow the operation of one or more
zone(s) in case of through fault during a circuitry fault with 2 more options:
1. Alarm and No blocking!!!
An alarm is provided and this alarm can only be reset manually,
The zone is not blocked!!!
2. Alarm Self-Reset and No blocking!!!
An alarm is provided.
The zone is not blocked!!!
2.1.1.4.2 Options for a PU error mode
When something happens that creates a loss of communication for a Zone such as loss of
power supply on a Peripheral Unit or fibre optic cut etc…, it is detected by the Central Unit.
To avoid maloperation in case of switch on to a through fault during maintenance for
example, there are 3 options:
1. Blocking Latched
An alarm is provided and this alarm can only be reset manually,
The zone is blocked and this blocking can only be reset manually.
2. Alarm Latched
An alarm is provided and this alarm can only be reset manually,
The zone is blocked and this blocking will be automatically reset once the
communication will be reinstated and after the set reset timer.
3. Self-Reset
An alarm is provided and the zone is blocked.
The alarm and the blocking will be automatically reset once the communication will be
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