ABB VM4 1SBN030105T1000 Mechanical Interlock for AF Contactors

The ABB VM4 (article 1SBN030105T1000) is a mechanical interlock unit that fits between two contactors to enforce mutual exclusion - when one contactor is closed, the VM4 physically prevents the other from closing. It is compatible with 3-pole and 4-pole AF09 to AF38, AFC09 to AFC38, and AFS09 to AFS38 ABB contactors, and mounts side-by-side without consuming any additional panel width.

Technical specifications:

• Series: VM4
• ABB article number: 1SBN030105T1000
• EAN: 3471523130609
• Compatible contactor ranges: AF09...AF38, AFC09...AFC38, AFS09...AFS38
• Compatible pole configurations: 3-pole and 4-pole
• Mounting style: side-by-side between two contactors, no additional width required
• Included accessories: 2 fixing clips (BB4)

Features and benefits:

• Mechanical interlock action prevents both contactors from being closed simultaneously, eliminating the risk of phase short-circuit in reversing or changeover circuits.
• Side-by-side installation adds no extra width to the contactor assembly, keeping the panel footprint compact.
• Covers a broad range of ABB AF, AFC, and AFS series contactors from frame 09 through 38 in a single accessory.
• Supplied with two BB4 fixing clips so no additional hardware is needed for mounting.
• Purely mechanical operation means the interlock function is independent of control voltage or auxiliary supply.

Applications:

• Reversing motor starters where forward and reverse contactors must never close at the same time.
• Star-delta starters requiring interlocking between the star and delta contactors.
• Changeover and transfer circuits where two supply paths must be mutually exclusive.
• Any two-contactor panel assembly in the AF09-AF38 / AFC09-AFC38 / AFS09-AFS38 range that requires hardware-enforced interlock protection.

Also known as: ABB VM4, VM4 1SBN030105T1000, 1SBN030105T1000, mechanical interlock for AF contactors, contactor interlock unit.