WL Circuit Break er
Function overview of the electronic trip units
Basic Functions ETU745
Long-time overcurrent protection
Function can be switched ON/OFF –
Setting range
I
R
=
I
n
x …
0.4, 0.45, 0.5, 0.55, 0.6,
0.65, 0.7, 0.8, 0.9, 1
Switch-selectable overload protection
(
I
2
t or
I
4
t dependent function)
Setting range of time delay class
t
R
at
I
2
t
(seconds)
2, 3.5, 5.5, 8, 10,
14, 17, 21, 25, 30
Setting range of
t
R
at
I
4
t
(seconds)
1, 2, 3, 4, 5
Thermal memor
(via (on/off via key pad or communications)
(on/off via key pad or communications)
slide switch)
Phase loss sensitivity at
t
sd
=20ms (M)
N-conductor protection
Function can be switched ON/OFF (via slide switch)
N-conductor setting range
I
N
=
I
n
x 0.5 … 1
Short-time delayed overcurrent protection
Function can be switched ON/OFF
(via rotary switch)
Setting range
I
sd
=
I
n
x …
1.25, 1.5, 2, 2.5,
3, 4, 6, 8, 10, 12
Setting range of
t
sd
, fixed
(seconds)
0.02 (M), 0.1, 0.2,
0.3, 0.4, OFF
Switch-selectable short-time delayed
short-circuit protection
(
I
2
t
dependent function)
(via rotary coding switch)
Setting range of
t
sd
at
I
2
t
(seconds)
0.1, 0.2, 0.3, 0.4
Zone Selective Interlocking (ZSI) function per CubicleBUS module
Instantaneous overcurrent protection
Function can be switched ON/OFF,
Extended Instantaneous Protection
is enabled when OFF
(via rotary coding switch)
Setting range
I
i
=
I
n
x …
1.5, 2.2, 3, 4, 6, 8, 10, 12
0.8 x
I
cw
= max, OFF =
I
cw
=EIP
Ground fault protection O (field installable module)
Trip and alarm function
Detection of the ground fault current
by residual summing method
Detection of the ground fault current
by direct summing method
Setting range of the
I
g
for trip , B, C, D, E (100… 1200A)
Setting range of the
I
g
for alarm A,
A,
B, C, D, E (100… 1200A)
Setting range of the
t
g
(seconds)
0.1, 0.2, 0.3, 0.4, 0.5
Switch-selectable
ground fault protection
(
I
2
t
/ fixed)
Setting range
t
g
at
I
2
t
0.1, 0.2, 0.3, 0.4, 0.5
ZSI ground function per CubicleBUS module
L
N
S
I
G
3
I
n
2
time delay
time delay
time delay
time delay
time delay
ETU776
–
40-100% of In (Adjustable in Amps )
2 … 30 (step: 0.1s)
1 … 5 (step: 0.1s)
(via key pad or communications)
(via key pad or communications)
(via key pad or communications)
(via key pad or communications)
(via key pad or communications)
0
.5 … 2, OFF
1.25 … 0.8 x I
cw
= max
(step: 10A)
M, 0.08 … 0.4, OFF (step: 0.001s)
0.1 … 0.4 (step: 0.001s)
per CubicleBUS module
1.5 x
I
n
…0.8 x
I
cs
= max, OFF =
I
cw
=EIP
O (field installable module)
A … E (step: 1A)
A … E (step: 1A)
0.1 … 2.0 (step: 0.001s)
0.1 … 2.0 (step: 0.001s)
per CubicleBUS module
1
1
available
– not available
O optional
Extended Instantaneous Protection (EIP) allows the WL circuit breaker to be applied at the withstand rating of
the circuit breaker with minus 0% tolerance; this means there is no instantaneous override at all. EIP further
enables the circuit breaker to be applied up to the full instantaneous rating of the circuit breaker in systems
where the available fault current exceeds the withstand rating.
2
Note: ETU776 settings via communications: 10A steps for Instantaneous and Short Time pickup, all others 1A steps.
Via ETU Keypad: Below 1000A: 10A steps 1000A-1600A: 50A steps
1600A-10000A: 100A steps Above 10000A, 1000A steps
1
Notes:
M = Motor protection setting indicates phase loss sensitivity is enabled. LT pick-up reduced 80% when phase unbalance > 50%. ST = 20 ms
Communications = Setting the parameters of the trip unit
via the Breaker Data Adapter, MODBUS, or PROFIBUS
Key pad = Direct input the trip uniton
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