Siemens WL User Manual

Electronic Trip Unit
WL Circuit Breaker
1/4
WL Selection and Application Guide • 2005
Selection criteria for
WL Circuit Breakers
The basic criteria for selecting circuit
breakers is:
Maximum Available Short-Circuit at
the installation point. This value
determines the short-circuit current
interrupting rating or short-circuit
current withstand rating of the circuit
breaker.
Rated Current I
n
which is to flow
through the respective circuit breaker
continuously. This value may not be
greater than the maximum rated
current of the circuit breaker. The
rated current for the WL is
determined by the rating plug,
up to the maximum frame rating.
Ambient Temperature of the circuit
breaker. This is usually the
temperature inside the cubicle.
Design of the circuit breaker.
Protective Functions of the circuit
breaker. These are determined by
selection of the appropriate trip unit.
Trip Unit Functions
Basic Protective Functions ETU725 ETU727
Long-time overcurrent protection L ●●
Short-time delayed overcurrent protection S ●●
Instantaneous overcurrent protection I ●●
Neutral conductor protection N -- ●
Ground fault protection G -- ●
Additional Functions
Selectable neutral protection -- ●
Defeatable short-time protection ●●
Defeatable instantaneous protection -- --
Selectable thermal memory -- --
Zone selective interlocking -- --
Selectable I
2
t or fixed short-time delay -- --
Adjustable instantaneous pick-up -- --
Selectable I
2
t or I
4
t long-time delay -- --
Adjustable short-time delay and pick-up ●●
Selectable and adjustable neutral protection -- --
Dual protective setting capability -- --
Dynamic arc-flash sentry -- --
Extended instantaneous protection ●●
Parameterization and Displays
Parameterization by rotary switches (10 steps) ●●
Parameterization by communication (absolute values) -- --
Parameterization by menu/keypad (absolute values) -- --
Remote parameterization of the basic functions -- --
Remote parameterization of the additional functions -- --
Alphanumeric LCD -- --
Graphical LCD -- --
Metering Function
Metering function Plus -- --
Communication
CubicleBUS -- --
Communication via PROFIBUS-DP -- --
Communication via the MODBUS -- --
Communication via the Ethernet (BDA) -- --
● standard -- not available ❍ optional
1 Fixed short-time delay only
1
1
For detailed information on the electronic trip unit functions see pages 1/36 thru 1/39
WL_SA_intro-sec1.qxd 2/7/05 1:20 PM Page 6

Siemens WL Specifications

General

Brand	Siemens
Model	WL
Category	Circuit breakers
Language	English