![Thytronic XMR-A 4l+1A Manual Download Page 284](http://html1.mh-extra.com/html/thytronic/xmr-a-4l-1a/xmr-a-4l-1a_manual_1113984284.webp)
284
FUNCTION CHARACTERISTICS
ϑ
E
>>,
ϑ
E
>>>,
ϑ
E
>>>>) may be adjusted (setting range 0…359° common for the three phases).
The the characteristic angle setting (positive when clockwise compared the polarizing voltage) spe-
cifies the angular displacement of the characteristic axis standing for the trip bisector of the tripping
zone. For isolated neutral systems with a 90° characteristic angle setting, faults towards the LINE
are detected, while with a 270° characteristic angle setting, faults towards the BUS are detected. All
the named parameters can be set separately for the four thresholds and for definite or inverse time
settings menu. For each of the four thresholds (
I
EDC
>,
I
EDC
>>,
I
EDC
>>>,
I
EDC
>>>>) the half operating
sector may be adjusted (setting range 0…180° simmetrically regarding the characteristic axis). All
the parameters can be set separately for the four thresholds and for definite or inverse time settings
menu.
VT supervision
For all the four thresholds
I
EDC>
,
I
EDC>>
,
I
EDC>>>
,
I
EDC>>>>
, the operating mode when the 74VT function
is active may be defined:
• OFF: no action are issued by 74VT.
• Block: all the four thresholds are blocked when the 74VT function is active.
• Not directional: all the four thresholds are switched from directional to not directional criteria
when the 74VT function is active.
The 74VT information may issued from internal 74VT function or from an external signal acquired by
means a binary input.
If a binary input is designed for 74VText, for all the four thresholds, the operating mode when the 74VT
function is active may be defined:
• OFF: no action are issued by 74VT.
• Block: all the four thresholds are blocked when the 74VT external signal is active.
• Not directional: all the four thresholds are switched from directional to not directional criteria
when the 74VT external signal is active.
Malfunctioning of the directional overcurrent elements can be avoided when VTs secondary fault
will arise (fuse or MCB tripping) by switching the overcurrent directional to non directional overcur-
rent protection
The
74VTint67NC
and
74VText67NC
parameters may be set as
OFF, Block, Not directional
inside the
Set \ Profile A (or B) \ Directional earth fault overcurrent-67N(Comp) \
Common configura-
tion
menu, while the
74VText
function must be assigned to the selected binary inputs inside the
Set
\ Board 1(2) inputs \ Binary input IN1-1...(IN1-x)
menus.
For all the four thresholds (common for all thresholds) an insensibility zone may be enabled in the
voltage-current plane.
If enabled, the insensibility zone is user adjustable by means the M multiplier (common for all thre-
sholds); the rectangle defined by the current and voltage thresholds and the same multiplied by M
becomes a No trip zone.
Such insensibility zone may be useful to avoid unwanted trip in the presence of some fixed residual
current and/or voltage (e.g. CT and or VT errors in the residual measurements).
The
Insens-Zone(C)
(
OFF, ON
) and
M(C)
parameters may be adjusted inside the
Set \ Profile A
(or B) \ Directional earth fault overcurrent-67N(Comp) \
Common configuration
menu
.
char-F67NC-IeUe.ai
Voltage/current characteristic concerning the earth fault overcurrent element - 67N(Comp)
with insensibility zone disabled
Voltage/current characteristic concerning the ground directional overcurrent - 67N(Comp)
with insensibility zone enabled
I
E2
I
EDC
>,
I
EDC
>>,
I
EDC
>>>,
I
EDC
>>>>
M∙
I
EDC
>, M∙
I
EDC
>>, M∙
I
EDC
>>>, M∙
I
EDC
>>>>
M∙
U
ED
>, M∙
U
ED
>>, M∙
U
ED
>>>, M∙
U
ED
>>>>
TRIP
U
E
U
EC
I
E2
I
EDC
>,
I
EDC
>>,
I
EDC
>>>,
I
EDC
>>>>
U
ED
>,
U
ED
>>,
U
ED
>>>,
U
ED
>>>>
U
ED
>,
U
ED
>>,
U
ED
>>>,
U
ED
>>>>
TRIP
U
E
U
EC
XMR-D EQUIPMENT MANUAL
Ed. 2.9 - 02/2021