Setting Example - ABB REG670 Applications Manual

Section 9
Current protection
9.2.3.2
330
For ANSI inverse time characteristics, all three types of reset time characteristics are
available: instantaneous (1), IEC (2 = set constant time reset) and ANSI (3 = current
dependent reset time).
For IEC inverse time characteristics, the possible delay time settings are instantaneous
(1) and IEC (2 = set constant time reset).
For the customer tailor-made inverse time delay characteristics (type 17), all three
types of reset time characteristics are available: instantaneous (1), IEC (2 = set
constant time reset) and ANSI (3 = current dependent reset time). If the current-
dependent type is used, settings pr, tr and cr must be given.
tResetx: Constant reset time delay in seconds for step x.
tPCrvx, tACrvx, tBCrvx, tCCrvx: These parameters are used by the customer to create
the inverse time characteristic curve. See equation
equation. For more information, refer to Technical manual.
æ
ç
A
[ ]
ç
=
t s
ç p
æ ö
i
ç ç ÷ -
C
è è ø
in
>
EQUATION1261 V2 EN
tPRCrvx, tTRCrvx, tCRCrvx: These parameters are used by the customer to create the
inverse reset time characteristic curve. For more information, refer to Technical
manual.
HarmRestrainx: Enables the block of step x from the harmonic restrain function (2nd
harmonic). This function should be used when there is a risk of an unwanted trip
caused by power transformer inrush currents. It can be set to Off/On.

Setting example

Directional phase overcurrent protection, four steps can be used in different ways,
depending on the application where the protection is used. A general description is
given below.
The operating current setting of the inverse time protection, or the lowest current step
of the definite time protection, must be defined so that the highest possible load
current does not cause protection operation. The protection reset current must also be
considered so that a short peak of overcurrent does not cause the operation of a
protection even when the overcurrent has ceased. This phenomenon is described in
Figure 174.
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
ö
÷
÷
+ ×
B IxMult
÷
÷
ø
1MRK 502 071-UEN -
181 for the time characteristic
(Equation 181)
Application manual