3WL air circuit breakers
3.4 Functions and parameters
3WL/3VL circuit breakers with communication capability - PROFIBUS
54
System Manual, 03/2011, A5E01051353-02
3.4.2
Load management
Load management is used to avoid peaks in the load curve or to reduce their effects. Brief
peaks can result in a circuit breaker overload and thus a tripping operation, or they can result
in the energy supplier raising the price. Energy prices are generally calculated based on the
maximum consumption values. Brief peaks can result in assignment to another tariff group
and thus a higher energy price.
From trip unit ETU45B, the SENTRON WL provides two current thresholds for local load
management. Load shedding is the upper threshold, and load pick up is the lower threshold.
Both values can be used locally, or in higher-level systems such as a PLC, to briefly shut
down parts of the loads (e.g. air conditioners) so that the peaks in the load curve are
reduced.
The figure below explains the functional principle of the load management functions "load
shedding" and "load pick up". This is based on a circuit breaker with an overload parameter
of 1000 A.
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Figure 3-12 Load management functions: Load shedding and load pick up
Important: Violation of the upper or lower thresholds never results in a circuit breaker trip and
instead only generates a message!
