18
DMC3S - Manual - 08 - 2021
—
Neutral current unbalance - 51(SQL)
Threshold I
SQL
>
Type of characteristic (
I
SQL
>
Curve
) DEFINITE,
IEC/BS A, B, B-LI, C
Reset delay
I
> (
t
>
RES
)
0.00...100.0 s
0.00...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
Definite time
First definite time threshold (
I
SQL
>
def
)
0.005...25.0
I
n
0.050...0.995
I
n
(step 0.005
I
n
)
1.00...9.99
I
n
(step 0.01
I
n
)
10.0...25.0
I
n
(step 0.1
I
n
)
Operating time (
t
SQL
>
def
) 0.05...1000
s
0.05...9.99 s (step 0.01 s)
10.0...99.9 s (step 0.1 s)
100...1000 s (step 1 s)
Shrink time trip (
t
cISQL
>
def
)
0.05...1000
s
0.05...9.99 s (step 0.01 s)
10.0...99.9 s (step 0.1 s)
100...1000 s (step 1 s)
Shrink activation time (
t
atcISQL
>
def
)
1...60 s (step 1 s)
Inverse time
[1]
First inverse time threshold (
I
SQL
>
inv
)
0.005...2.00
I
n
0.005...0.995
I
n
(step 0.005
I
n
)
1.00...2.00
I
n
(step 0.01
I
n
)
Operating time (
t
SQL
>
inv
) 0.02...60.0
s
0.02...9.99 s (step 0.01 s)
10.0...60.0 s (step 0.1 s)
—
Overvoltage - 59
Common configurations:
Type of voltage measurement for 59 - phase-to-phase/phase (
U
type59)
[2]
U
ph-ph
/
U
ph-n
Operating logic 59 (
Logic
59)
AND/OR
Threshold U>
Type of characteristic
U
> (
U
>
Curve
)
DEFINITE/INVERSE
Definite time
First 59 definite time threshold (
U>
def
)
0.500...1.500
U
n
(step 0.001
U
n
)
Operating time
U>
def
(
t
U
>
def
)
0.05...1000
s
0.05...9.99 s (step 0.01 s)
10.0...99.9 s (step 0.1 s)
100...1000 s (step 1 s)
Inverse time
[3]
First 59 inverse time threshold (
U>
inv
)
0.500...1.500
U
n
(step 0.001
U
n
)
Operating time (
t
U
>
inv
)
0.10...100.0
s
0.10...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
Threshold U>>
Definite time
Second definite time threshold (
U>>
def
)
0.500...1.500
U
n
(step 0.001
U
n
)
Operating time (
t
U
>>
def
)
0.05...1000
s
0.05...9.99 s (step 0.01 s)
10.0...99.9 s (step 0.1 s)
100...1000 s (step 1 s)
Note 2
Inverse time curve IEC 255-3/BS142 (type A or SIT):
t = 0.14 · t
SQL
>
inv
/ [(I
SQL
/I
SQL
>
inv
)
0.02
- 1]
Very inverse time curve IEC 255-3/BS142 (type B or VIT):
t = 13.5 · t
SQL
>
inv
/ [(I
SQL
/I
SQL
>
inv
) - 1]
Long inverse time curve (IEC 255-3/BS B LTI):
t = 120 · t
SQL
>
inv
/ [(I
SQL
/I
SQL
>
inv
) - 1]
Extremely inverse time curve IEC 255-3/BS142 (type C or EIT):
t = 80 · t
SQL
>
inv
/ [(I
SQL
I
SQL
>
inv
)
2
- 1]
t
:
operating time, minimum operating time:
0.1
s
t
SQL
>
inv
:
operating time regulation
I
SQL
>
inv
:
trip threshold regulation
I
SQL
:
measured current
Asymptotic reference value:
1.1
I
SQL
>
inv
Dynamic: 1.1 ≤ I
SQL
/I
SQL
>
inv
≤ 20, with regulation I
SQL
>
inv
greater than
2.5
I
SQLn
, the upper limit of the measurement range is
30
I
SQLn
Note 2 With
U
ph-ph
set on the MMI, all thresholds are expressed in p.u.
U
n
,
With
U
ph-n
set on the MMI, all thresholds are expressed in p.u.
E
n
Note 3 The general formula for inverse time curves is: t = (0.5 ∙
t
U
>
inv
) / [(
U
/
U
>
inv
) - 1]
t = operating time (in seconds)
t
U
>
inv
= operating time regulation (in seconds), U = measured voltage
U
>
inv
= trip threshold regulation
