25 – 7
Function Overview of the Electronic Trip Units
Basic Functions ETU725 ETU727 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, 0.4, 0.45, 0.5, 0.55, 0.4, 0.45, 0.5, 0.55, 0.6,
0.6, 0.65, 0.7, 0.8, 0.6, 0.65, 0.7, 0.8, 0.65, 0.7, 0.8, 0.9, 1
0.9, 1 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) 10s, fixed at 6 x
I
r
10s, fixed at 6 x
I
r
2, 3.5, 5.5, 8, 10,
14, 17, 21, 25, 30
Setting range of time delay
t
R
at
I
4
t
(seconds) – – 1, 2, 3, 4, 5
Thermal memory – – ✔ (via slide switch)
Phase loss sensitivity at
t
sd
=20ms (M) at
t
sd
=20ms (M) at
t
sd
=20ms (M)
N-conductor protection – ✔✔
Function can be switched ON/OFF – ✔ (via slide switch) ✔ (via slide switch)
N-conductor setting range
I
N
=
I
n
x … – 1 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, 1.25, 1.5, 2, 2.5, 1.25, 1.5, 2, 2.5,
3, 4, 6, 8, 10, 12 3, 4, 6, 8, 10, 12 3, 4, 6, 8, 10, 12
Setting range of time delay
t
sd
, fixed
(seconds) 0, 0.02 (M), 0.1, 0, 0.02 (M), 0.1, 0.02 (M), 0.1, 0.2,
0.2, 0.3, 0.4 0.2, 0.3, 0.4 0.3, 0.4, OFF
Switch-selectable short-time delay
short-circuit protection
(
I
2
t
dependent function) – fixed only – fixed only ✔ (via rotary switch)
Setting range of time delay
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 switch)
Setting range
I
i
=
I
n
x …
I
i
= 0.8 x
I
cw
I
i
= 0.8 x
I
cw
1.5, 2.2, 3, 4, 6, 8, 10, 12
50kA max 50kA max 0.8 x
I
cw
= max, OFF=
I
cw
=EIP
Ground fault protection – ✔ (standard)
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 – A, B, C, D, E A, B, C, D, E
Setting range of the
I
g
for alarm – – A, B, C, D, E
Setting range of the time delay
t
g
(seconds) – 0.1, 0.2, 0.3, 0.4, 0.5 0.1, 0.2, 0.3, 0.4, 0.5
Switch-selectable
ground fault protection
(
I
2
t
/ fixed) – – ✔
Setting range time delay
t
g
at
I
2
t
– – 0.1, 0.2, 0.3, 0.4, 0.5
ZSI ground function – – per CubicleBUS module
✔ available
– not available
O optional
L
N
S
I
G
Extended Instantaneous Protection (EIP) allows the WL breaker to be applied at the withstand rating
of the breaker with minus 0% tolerance; that means no instantaneous override whatsoever. EIP further
enables the circuit breaker to be applied up to the full instantaneous rating of the breaker on systems
where the available fault current exceeds the withstand rating.
Ground Fault Module cannot be removed after installation.
1
2
I
n
2
1
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