1. Scope
This specification covers a full set of compatible accessories for standard moulded case circuit breaker series, including functional control accessories, operating accessories, wiring & mounting accessories, and supporting technical documentation. All accessories are designed to be mechanically and electrically matched with corresponding MCCB main units, complying with low-voltage switchgear standards.
2. Functional Accessories & Performance Description
2.1 Auxiliary Contacts
• Mechanical linkage synchronized with MCCB main contacts; contact status changes simultaneously with breaker closing / opening operation.
• Used for remote status indication, interlock control and signal feedback of normal switch-on/off states of the circuit breaker.
2.2 Tripping Signal Contacts (Alarm Contacts)
• Activates only when the MCCB trips electrically due to overload, short-circuit, undervoltage or shunt trip fault conditions.
• Provides independent fault alarm signal output to distinguish normal manual opening from protective tripping.
2.3 Shunt Trip Releases
• Remote electrical tripping accessory; triggers breaker opening upon energization of the coil.
• Enables remote emergency cut-off, automatic interlock cut-off and centralized power-off control.
2.4 Undervoltage Releases
• Performs protective tripping when supply voltage drops below specified threshold or loses power completely.
• Prevents automatic re-closing of the breaker after power recovery to avoid unsafe equipment startup.
2.5 Remote Motor Operators
• Motor-driven electric operating mechanism for remote automatic closing and opening of MCCB.
• Supports centralized automation control, remote on/off operation without manual on-site manipulation.
2.6 Rotary Handle Operating Mechanisms
• External rotary handle assembly for cabinet door mounting.
• Allows manual breaker operation from outside the electrical enclosure while maintaining enclosure protection integrity; supports lockable handle for safety isolation.
2.7 Connection Terminals & Terminal Covers
• Extended wiring terminals for flexible cable connection with large cross-section conductors.
• Insulated terminal protective covers to prevent accidental contact with live conductive parts, improving operation safety.
2.8 Mounting Depth Spacers & Adaptors
• Positioning spacers and conversion adaptors for standardized installation adjustment.
• Compensates mounting depth differences, realizes interchangeable installation of fixed, plug-in and draw-out MCCB structures.
2.9 Phase Barriers
• Insulating phase separation partitions installed between pole phases of the circuit breaker.
• Blocks arc flash propagation between phases, enhances dielectric safety under short-circuit conditions.
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