Siemens SENTRON 3WL10 - Page 78

Description
2.8 Electronic trip unit ETU
3VA27 molded case circuit breakers & 3WL10 air circuit breakers
76 Manual, 10/2018, L1V30499596002-01
Protection functions of the ETU
ETU650 LSI
ETU660 LSIG
Switchover to the alternative of the external,
directly measured ground-fault protection
— ●
Default value: OFF
Switchover to alternative operating values with
ground-fault current during the switch-on phase
(inrush adaptation) for tripping characteristic t=k
(fixed) possible
— ●
Default value: OFF
Setting range of the switch-on phase (inrush
adaptation)
— 0.1 to 30 s (in steps of 0.01)
Default value: 0.1
Setting range I
g
= I
n
x … during the switch-on
phase (inrush adaptation)
— 0.2 to 1 (in steps of 0.01)
Default value: 1
Extended parameter range with ext. auxiliary
power supply of the ETU
— - I
g
full range,
otherwise I
g
limited to
min. 0.2 I
n
or 0.25 I
n
(for
I
n
= 400A)
- t
g
possible instantaneously
G direct
GF direct: Ground-fault protection direct measu-
rement
— ●
Default set: Not installed
Protection function can be selected
• R
c
- residual-current protection
(with summation current transformer)
• G
ret
- ground-fault return protection
(transformer in the star point)
— Ground return CT; Rc CT;
necessary
Rc - residual-current protection
(with summation current transformer)
— ●
Alternative to GF and G_ret
Default value: OFF
Possible with current sensor
Rc & MF advanced
Setting range operating value residual current
I
∆n
— 3; 5; 7; 10; 20; 30 A
Default value: OFF
Possible with current sensor
Rc & MF advanced
Setting range for delay time t
∆n
— 0.06; 0.1; 0.2; 0.3; 0.4; 0.5;
0.8 s
Gret ground-fault return protection
(ground return - transformer in the star point)
— ●
Alternative to GF and Rc
Design of G
ret
transformer
(ground fault return CT, I
CT_rating
)
— 100; 250 A
Default value: 100 A
Setting range operating value ground fault re-
turn I
g_ret
= I
CT_rating
x ...
— 0.1 to 1 x I
CT_rating
(in steps of
0.001)
Default value: 0.1
Setting range of delay time t
g_ret
(fixed) t=k — 0.1 to 1 s (in steps of 0.05)
Default value: 0.1s
Setting range for delay time t
g_ret
at I²t (refe-
rence point 4 x I
n
)
— 0.1s to 1s (in steps of 0.05)