![background image](http://html.mh-extra.com/html/abb/615-series-ansi/615-series-ansi_technical-manual_4665669.webp)
Section 11
1MAC050144-MB C
General function block features
662
615 series ANSI
Technical Manual
User-programmable delayed inverse reset
The user can define the delayed inverse reset time characteristics with the following
formula using the set
Curve parameter D
.
(Equation 84)
t[s]
Reset time (in seconds)
k
set
Time multiplier
D
set
Curve parameter D
I
Measured current
I>
set
Pickup value
11.2.3
Inverse-timer freezing
When the
BLOCK
input is active, the internal value of the time counter is frozen at the
value of the moment just before the freezing. Freezing of the counter value is chosen when
the user does not wish the counter value to count upwards or to be reset. This may be the
case, for example, when the inverse-time function of an IED needs to be blocked to enable
the definite-time operation of another IED for selectivity reasons, especially if different
relaying techniques (old and modern relays) are applied.
Activating the
BLOCK
input alone does not affect the operation of the
PICKUP
output. It
still becomes active when the current exceeds the set
Pickup value
, and inactive when the
current falls below the set
Pickup value
and the set
Reset delay time
has expired.
The delayed inverse-time reset is not available for IEC-type inverse time
curves.
t s
D
I
I
k
[ ]
=
>
⎛
⎝⎜
⎞
⎠⎟
−
⎛
⎝
⎜
⎜
⎜
⎜⎜
⎞
⎠
⎟
⎟
⎟
⎟⎟
⋅
2
1
The selected blocking mode is "Freeze timer".
The activation of the
BLOCK
input also lengthens the minimum delay value
of the timer.
Summary of Contents for 615 Series ANSI
Page 1: ...Relion Protection and Control 615 series ANSI Technical Manual ...
Page 2: ......
Page 29: ...1MAC050144 MB C Section 615 series ANSI 22 Technical Manual ...
Page 389: ...Section 4 1MAC050144 MB C Protection functions 382 615 series ANSI Technical Manual ...
Page 485: ...Section 6 1MAC050144 MB C Supervision functions 478 615 series ANSI Technical Manual ...
Page 635: ...Section 10 1MAC050144 MB C Other functions 628 615 series ANSI Technical Manual ...
Page 711: ...Section 16 1MAC050144 MB C Glossary 704 615 series ANSI Technical Manual ...
Page 712: ......