ABB vm4 mechanical interlock unit

Why Choose the ABB VM4 Mechanical Interlock Unit?

The ABB VM4 mechanical interlock unit is a compact and highly reliable contactor interlocking accessory designed for use with ABB AF, AFC and AFS contactors in industrial motor control and automation systems. Identified by part number 1SBN030105T1000, this accessory forms part of the trusted ABB VM interlock series, engineered to mechanically prevent simultaneous operation of adjacent contactors in reversing and changeover applications.

The VM4 is specifically designed for the side-by-side interlocking of two 3-pole or 4-pole ABB contactors without adding extra panel width. When mounted between two contactors, the unit mechanically prevents one contactor from closing while the other remains energised, improving operational safety and preventing damaging short circuits or parallel motor operation.

Featuring an ultra-compact design and supplied with 2 fixing clips (BB4), the VM4 delivers dependable interlocking performance in motor reversing starters, HVAC systems, machinery and industrial automation applications.

Key Advantages

• Reliable mechanical interlocking of adjacent contactors.
• Prevents simultaneous closure of contactors for improved safety.
• No additional installation width required.
• Compatible with ABB AF, AFC and AFS contactor ranges.
• Compact lightweight construction for control panels.
• Supplied with 2 fixing clips (BB4).
• Suitable for reversing starters and changeover circuits.

Key Features

• ABB VM4 mechanical interlock unit.
• Designed for side-by-side contactor interlocking.
• Prevents simultaneous contactor operation.
• Compatible with 3-pole and 4-pole ABB contactors.
• No auxiliary contacts included.
• Compact installation without added panel width.
• Includes 2 fixing clips (BB4).
• Mechanical switching frequency up to 1800 cycles/hour.
• Suitable for industrial motor control systems.
• High mechanical durability and long service life.

Technical Specifications

• Manufacturer: ABB
• Series: VM4
• Part number: 1SBN030105T1000
• Product type: Mechanical interlock unit
• Accessory type: Contactor interlock
• Mounting method: Side-by-side between contactors
• Compatible contactors: ABB AF09...AF38, AFC09...AFC38, AFS09...AFS38
• Compatible poles: 3-pole and 4-pole contactors
• Additional width required: None
• Included accessories: 2 × BB4 fixing clips
• Maximum mechanical switching frequency: 1800 cycles/hour
• Protection rating: IP20
• Standards: IEC/EN 60947-4-1, UL 60947-1, UL 60947-4-1, CSA C22.2
• Product width: approx. 20 mm
• Product height: approx. 19.8 mm
• Product depth: approx. 10 mm
• Weight: approx. 0.005 kg
• EAN: 3471523130609

Reliable Mechanical Interlocking for Motor Control Systems

Mechanical interlock units are widely used in reversing motor starters and changeover circuits to prevent two contactors from closing simultaneously. This protects motors, power circuits and connected equipment from electrical faults caused by opposing outputs or unintended parallel operation.

The ABB VM4 provides a compact and reliable solution for industrial automation engineers, machine builders and panel manufacturers requiring safe and dependable interlocking functionality inside modern control cabinets.

Typical Applications

• Reversing motor starters.
• Forward and reverse motor control systems.
• HVAC compressor and fan interlocking.
• Industrial machinery and automation systems.
• Conveyor and material handling systems.
• Changeover and transfer switching applications.

Trusted by Industrial Control Engineers Worldwide

ABB VM4 mechanical interlock units are widely used by automation engineers and panel builders to provide safe, dependable contactor interlocking in industrial motor control systems.