Disconnectors, Earthing Switches and Accessories
Disconnectors, earthing switches, operating mechanisms and voltage indicators perform different functions. Define the required circuit states and operating relationships before selecting mechanism and indication interfaces. A single set of interruption ratings cannot describe all these devices.
Choose switching devices by circuit state
Two-position, three-position and double-throw arrangements need defined connections at each position. Isolation does not automatically include load breaking, and double-throw construction does not establish automatic source-transfer logic. Confirm permitted operation from the circuit arrangement.
- Connected and isolated states at each position
- Inclusion of an earthing arrangement
- Operating interlocks with other devices
Distinguish earthing from fault clearing
Assess short-time withstand, peak withstand and making duties separately for an earthing switch. Fault interruption requires a device rated for that function. Match the earthing switch to the earthing circuit, operating shaft and position feedback.
- Earthing connections and contact layout
- Operating direction, travel and interlocks
- Separate evidence for each rated duty
Select accessories as part of a matched system
Mechanisms require matching torque, travel, output shafts and drive arrangements. Voltage indicators require compatible sensing or coupling interfaces. A mechanism is not a complete primary switch, and an unverified absence of indication is not proof of absence of voltage.
- Mechanism, motor or handle scope
- Indicator, coupling elements and wiring
- Position outputs and control requirements
Does an operating mechanism include the disconnector?
Confirm this separately. A mechanism supply may exclude primary contacts, insulating supports and earthing connections.
Does an unlit voltage indicator prove absence of voltage?
Do not rely on that alone. Confirm the detection system's function and conditions and follow the equipment's prescribed verification procedure.
Related selection resources
Discuss isolation, earthing or accessories
Provide circuit-position diagrams and interlock requirements. Identify whether you need the primary switch, drive mechanism or indication system and include the relevant interfaces.
Send project requirements
