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A-41
Functional units
Source changeover
General
To ensure the supply of energy at all times, certain electrical installations are
connected to two sources:
the normal source
the replacement source that steps in to supply the installation if the normal source
is not available.
Amechanical and/or electrical interlocking system between two Interpact, Compact
or Masterpact switch-disconnectors or circuit breakers (or a mixture) avoids
simultaneous connection of the two sources during switching.
The source-changeover system can be:
manual when the devices are mechanically interlocked
remote operated when there is also an electrical interlocking system
automatic, by adding an automatic controller that manages switching from one
source to another according to a number of external parameters.
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DD381669
Manual source-changeover system
This is the most simple system. A human operator is required and consequently, the
transfer from the normal source to the replacement source is delayed.
Amanual source-changeover system comprises two or three manually controlled
devices (circuit breakers or switch-disconnectors) that are mechanically interlocked.
The interlocking system avoids simultaneous connection (even transient) of the two
sources.
Remote-operated source-changeover system
This is the most commonly used system. No human intervention is required.
The transfer from the normal to the replacement source is managed electrically.
A remote-operated source-changeover system is made up of two or three devices
linked by an electrical interlocking system implemented in a number of manners.
Device control is backed up by a mechanical interlocking system that protects
against the consequences of an electrical malfunction and inhibits incorrect manual
operation.
Automatic source-changeover system
When a remote-operated source-changeover system is combined with an automatic
controller, the sources can be controlled automatically according to a number of
programmed operating modes.
This solution provides optimum energy management:
switching to a replacement source depending on any external conditions
management of sources
regulation
emergency source replacement, etc.
A communications function for dialogue with a supervisor is available for the
automatic controller.
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See the catalogue dedicated to Compact, Interpact and Masterpact source-
changeover systems (ref. ABTEDA-4101149EN).
Source-changeover systems
Compact / Masterpact
Switch-disconnectors