Search

Search

Electronic trip units

ETUs for line protection applications

The following electronic trip units are suitable for use in line protection applications:

  • ETU320 LI

  • ETU330 LIG

  • ETU350 LSI

  • ETU550 LSI

  • ETU560 LSIG

  • ETU850 LSI

  • ETU860 LSIG

Electronic trip unit ETU320 LI

ETU320 LI 3-pole:

63894353291.png

ETU320 LI 4-pole:

63894844683.png

Line protection - function LI

The electronic trip unit ETU320 has:

  • adjustable parameter settings Ir and tr for overload protection (L)

  • adjustable parameter setting Ii for instantaneous short-circuit protection (I)

  • With 4-pole versions only: Neutral conductor protection (N) which can be deactivated

ETU320 parameters:

Overload protection L:

Ir

adjustable in 10 steps of 0.4 to 1.0 x In

tr

adjustable in 10 steps of 0.5 to 12 /15 s or 17 s

tr is the tripping time at 6 x Ir

The ETU320 LI has a permanently active thermal image.

Instantaneous short-circuit protection I:

Ii

adjustable in 10 steps of 1.5 to 9 / 10 / 11 / 12 x In

(depending on size)

Neutral conductor protection N:

The neutral conductor protection function is available for 4-pole molded case circuit breakers only.

IN

In < 100 A: 1.0 x Ir or OFF

In ≥ 100 A: 0.5 / 1.0 x Ir or OFF

Electronic trip unit ETU330 LIG

ETU330 LIG 3-pole:

63895942155.png

ETU330 LIG 4-pole:

63896834827.png

Line protection - function LIG

The electronic trip unit ETU330 has:

  • adjustable parameter settings Ir and tr for overload protection (L)

  • adjustable parameter setting Ii for instantaneous short-circuit protection (I)

  • adjustable parameter settings Ig and tg for ground-fault protection (G)

  • With 4-pole versions only: Neutral conductor protection (N) which can be deactivated

ETU330 parameters:

Overload protection L:

Ir

adjustable in 10 steps of 0.4 to 1.0 x In

tr

adjustable in 10 steps of 0.5 to 12 /15 s or 17 s

tr is the tripping time at 6 x Ir

The ETU330 LIG has a permanently active thermal image.

Instantaneous short-circuit protection I:

Ii

adjustable in 10 steps of 1.5 to 9 / 10 / 11 / 12 x In

(depending on size)

Ground-fault protection G:

Ig

adjustable in 5 steps of 0.2 / 0.25 / 0.4 / 0.6 to 1.0 x In

(depending on size)

tg

adjustable to 100 ms or 300 ms, at 2 x Ig in each case

The ground-fault protection cannot be deactivated.

Neutral conductor protection N:

The neutral conductor protection function is available for 4-pole molded case circuit breakers only.

IN

In < 100 A: 1.0 x Ir or OFF

In ≥ 100 A: 0.5 / 1.0 x Ir or OFF

Electronic trip unit ETU350 LSI

ETU350 LSI 3-pole:

63897044363.png

ETU350 LSI 4-pole:

63897509899.png

Line protection - function LSI

The electronic trip unit ETU350 has:

  • adjustable parameter settings Ir and tr for overload protection (L)

  • adjustable parameter settings Isd and tsd for short-time delayed short circuit protection (S)

  • fixed parameter setting Ii for instantaneous short-circuit protection (I)

  • With 4-pole versions only: Neutral conductor protection (N) which can be deactivated

ETU350 parameters:

Overload protection L:

Ir

adjustable in 10 steps of 0.4 to 1.0 x In

tr

adjustable in 10 steps of 0.5 to 12 /15 s or 17 s

tr is the tripping time at 6 x Ir

The ETU350 LSI has a permanently active thermal image.

Short-time delayed short circuit protection S:

Isd

adjustable in 10 steps of 1.5 to 9 / 10 x Ir

tsd

adjustable in 6 steps of 0 to 0.4 s

with the reference point at Isd = 8 x Ir

The curve shape is I2t = constant.

Instantaneous short-circuit protection I:

Ii

Not adjustable: Permanently set to 9 / 10 / 11 / 12 x In
(depending on rated operational current and breaker size)

Neutral conductor protection N:

The neutral conductor protection function is available for 4-pole molded case circuit breakers only.

IN

In < 100 A: 1.0 x Ir or OFF

In ≥ 100 A: 0.5 / 1.0 x Ir or OFF

5-series and 8-series electronic trip units

Parameter input via display unit

With 5-series and 8-series electronic trip units, it is possible to set more parameters and scale the selection of parameters more finely than for 3-series trip units.

Parameters are set via the display unit and its buttons. This functionality is available, however, only if a separate, dedicated power supply is connected to the molded case circuit breakers.

Potential alternatives for this power supply:

  • 24 V supplied externally via:

    • EFB300 external function box

    • temporarily connected TD300 or TD500 test device

    • internal 24 V module

    • internal COM060 communication module

  • Current flow > 20 % In in one of the 3 phases

A description of the parameter display can be found in chapter "Operator controls".

Additional features of 8-series units

In addition to the features shared with 5-series trip units, 8-series units also offer:

  • An integrated voltage tap, plus an external voltage tap in the case of 3-pole molded case circuit breakers

  • Additional sensing of power measurements (function requires an external 24 V supply)

Electronic trip units ETU550 LSI and ETU850 LSI

ETU550 LSI 3-pole and 4-pole units:

63898184971.png

ETU850 LSI 3-pole and 4-pole units:

63898893963.png

Line protection - function LSI

The electronic trip units ETU550 and ETU850 have:

  • adjustable parameter settings Ir and tr for overload protection (L)

  • adjustable parameter settings Isd and tsd for short-time delayed short circuit protection (S)

  • adjustable parameter setting Ii for instantaneous short-circuit protection (I)

  • With 4-pole versions: adjustable parameter setting IN for neutral conductor protection (N)
    can be activated optionally for 3-pole versions

ETU550 / ETU850 parameters (3-pole version):

ETU550 / ETU850 parameters (4-pole version):

Overload protection L:

Ir

adjustable from 0.4 to 1.0 x In in absolute current values
Ir < 50 A: In steps of 0.5 A

Ir ≥ 50 A: In steps of 1 A

tr

adjustable from 0.5 to 12 / 15 / 17 / 20 / 25 s (depending on rated operational current and breaker size)
with a reference point of 6 x Ir.
In steps of 0.1 s

The ETU550 LSI and ETU850 LSI units have a thermal image.

Short-time delayed short circuit protection S:

Isd

adjustable from 0.6 to 9 / 10 x In

Isd < 50 A: In steps of 0.5 A

Isd ≥ 50 A: In steps of 1 A

tsd

adjustable from 0.05 to 0.5 s
with a reference point of Isd = 8 x Ir
in steps of 0.01 s

The curve shape I2t = constant can be deactivated.

Instantaneous short-circuit protection I:

Ii

Breaker sizes 100 A to 400 A:
adjustable from 1.5 to 10 / 12 x In

Size 630 A:
see tables above

In steps of 1 A

Neutral conductor protection N:

The neutral conductor protection function is available only for 3-pole molded case circuit breakers with external current transformer for N conductor for 4-pole molded case circuit breakers.

IN

adjustable in steps of 1 A

3-pole breakers with external current transformer for N conductor:
In < 63 A: 0.4 to 1.6 x In

In ≥ 63 A: 0.2 to 1.6 x In

4-pole breakers:
In < 63 A: 0.4 to 1.6 x In

In ≥ 63 A: 0.2 to 1.0 or 1.6 x In

Electronic trip units ETU560 LSIG and ETU860 LSIG

ETU560 LSIG 3-pole and 4-pole units:

63899676171.png

ETU860 LSIG 3-pole and 4-pole units:

63899744907.png

Line protection - function LSIG

The electronic trip units ETU560 and ETU860 have:

  • adjustable parameter settings Ir and tr for overload protection (L)

  • adjustable parameter settings Isd and tsd for short-time delayed short circuit protection (S)

  • adjustable parameter setting Ii for instantaneous short-circuit protection (I)

  • adjustable parameter settings Ig and tg for ground-fault protection (G)

  • With 4-pole versions: adjustable parameter setting IN for neutral conductor protection (N)
    optionally available for 3-pole versions

ETU560 / ETU860 parameters (3-pole version):

ETU560 / ETU860 parameters (4-pole version):

Overload protection L:

Ir

adjustable from 0.4 to 1.0 x In in absolute current values
Ir < 50 A: In steps of 0.5 A

Ir ≥ 50 A: In steps of 1 A

tr

adjustable from 0.5 to 12 / 15 / 17 / 20 / 25 s (depending on rated operational current and breaker size)
with a reference point of 6 x Ir.
In steps of 0.1 s

The ETU560 LSIG and ETU860 LSIG units have a thermal image which can be deactivated.

Short-time delayed short circuit protection S:

Isd

adjustable from 0.6 to 9 / 10 x In

Isd < 50 A: In steps of 0.5 A

Isd ≥ 50 A: In steps of 1 A

tsd

adjustable from 0.05 to 0.5 s
with a reference point of Isd = 8 x Ir
in steps of 0.01 s

The curve shape I2t = constant can be deactivated.

Instantaneous short-circuit protection I:

Ii

Breaker sizes 100 A to 400 A:
adjustable from 1.5 to 10 / 12 x In

Size 630 A:
see tables above

In steps of 1 A

Ground-fault protection G:

4-pole breakers or 3-pole breakers with external current transformer for N conductor detect ground fault currents by calculating the vector sum of the phase currents and the neutral conductor current.

Ig

adjustable from 0.2 / 0.25 / 0.4 / 0.6 to 1.0 x In

In steps of 1 A

tg

adjustable from 0.05 to 0.8 s
with a reference point of 2 x Ig

In steps of 0.01 s

An alarm threshold IgA between 0.2 to 1 x In can also be set. In steps of 1 A

The current-dependent curve shape I2t = constant can be deactivated.

The ground-fault protection function G can be deactivated.

Neutral conductor protection N:

The neutral conductor protection function is available only for 3-pole molded case circuit breakers with external current transformer for N conductor for 4-pole molded case circuit breakers.

IN

adjustable in steps of 1 A

3-pole breakers with external current transformer for N conductor:
In < 63 A: 0.4 to 1.6 x In

In ≥ 63 A: 0.2 to 1.6 In

4-pole breakers:
In < 63 A: 0.4 to 1.6 x In

In ≥ 63 A: 0.2 to 1.0 or 1.6 x In

1)

With 4-pole versions only:

63895527819_Table-1.png
63895527819_Table-2.png

1)

With 4-pole versions only:

63896382091_Table-1.png
63896382091_Table-2.png

1)

With 4-pole versions only:

63897796235_Table-1.png
63897796235_Table-2.png

1)

only 3-pole version with external current transformer for N conductor

63899359499_Table-1.png
63899359499_Table-2.png
63899543435_Table-1.png
63899543435_Table-2.png

1)

only 3-pole version with external current transformer for N conductor

63899839243_Table-1.png
63899839243_Table-2.png
63900035979_Table-1.png
63900035979_Table-2.png