Operation principle and hardware
description
Contents of this chapter
This chapter describes the intended use and construction of the semiconductor switch unit
ACS880-7407LC. The chapter also presents the type designation label and the type code.
Operation principle
The semiconductor switch unit protects the drive DC bus in a short-circuit situation. The
main component is a semiconductor DC breaker switch. The DC breaker switch breaks the
DC bus when it detects a fault current. This limits the current efficiently and rapidly due to
semiconductor technology. The DC breaker switch can be connected either to the DC+ or
DC- busbar.
• If it is necessary to break the fault current in both poles, it is possible to add two units (and
DC breaker switches) into the system, one connected to DC+ busbar and the other to DC-
busbar.
• Liquid-cooled
• Bidirectional functionality
• Three sizes
• When necessary, the unit can be equipped with fuses for backup protection (option +F260).
Refer to the appropriate requirements, such as, for example, the rule requirements of the
relevant classification society in case of marine projects.
• If isolation is required in addition to the short circuit and overload protection, it is possible
to combine the semiconductor switch unit with the DC incoming unit (ACS880-7207LC or
ACS880-7307LC).
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