CT
Current transformer
A current-measurement transformer used with metering and protection equipment.
SLD / Schematic
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1095 entries · Original illustrations
VT / PT
Voltage transformer
A transformer providing a voltage signal for metering or protection.
SLD / Schematic
CB
Circuit breaker
A switching device that can interrupt a circuit, with specified fault-interruption capability.
SLD / Schematic
Isolator
Disconnector
A switching device providing an electrical isolation function.
SLD / Schematic
LBS
Load-break switch
A switch with a specified capability to make and break normal load current.
SLD / Schematic
ES
Earthing switch
A switch used to connect an identified circuit section to earth.
SLD / Schematic
FU
Fuse
An overcurrent protective element that interrupts a circuit by melting its fuse link.
SLD / Schematic
Bus
Busbar
A common conductive connection distributing power to connected circuits.
SLD / Schematic
NO
Normally open contact
A contact shown open in the normal state defined for its device.
Schematic
NC
Normally closed contact
A contact shown closed in the normal state defined for its device.
Schematic
CO
Changeover contact
A contact arrangement switching a common connection between two contact paths.
Schematic
Coil
Relay coil
The operating element associated with a relay and its separately drawn contacts.
Schematic
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Small details. Different meanings.
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