Mersen USFMAC11 auxiliary microswitch for compatible UltraSafe three-pole USFM fuse modules, featuring early-break and late-make operation for contactor interlocking and safer fuse maintenance.
£22.29
The Mersen USFMAC11 is a compact auxiliary microswitch contact designed for use with Mersen UltraSafe™ three-pole fuse modules. It provides an early-break and late-make switching function that supports safer isolation and improved control integration in industrial motor circuits, machinery and automation panels.
When the USFMAC11 is installed in a compatible USFM fuse module and connected to an adjacent contactor, opening the fuse extractor handle operates the microswitch before the fuse is disconnected. This allows the contactor to drop out and remove the load, helping reduce the risk of opening the fuse module while the circuit is energised under load.
Its slim 9.1 mm-wide design integrates neatly with compact Mersen USFM assemblies and 45 mm IEC contactor arrangements. The accessory is suitable for both Midget and Class CC UltraSafe fuse modules, making it a practical choice for OEM machinery, motor control panels and industrial electrical systems requiring auxiliary status or interlocking functionality.
The Mersen USFMAC11 provides a mechanical-to-electrical interface between a compatible fuse module and an external control circuit. When the fuse extractor handle begins to open, the microswitch changes state early enough to signal or de-energise an associated contactor before the fuse contacts separate.
This operating sequence improves maintenance safety and helps protect connected equipment from switching under load. Its compact design also allows panel builders to add auxiliary control functionality without significantly increasing the footprint of the USFM motor protection assembly.
| Manufacturer | Mersen |
|---|---|
| Series | UltraSafe™ USFM |
| Model | USFMAC11 |
| Product type | Auxiliary contact microswitch |
| Contact operation | Early break / late make |
| Indication system | Yes |
| Indication system type | Microswitch |
| Short-circuit current rating | 200 kA |
| Compatible product range | Mersen UltraSafe three-pole fuse modules |
| Compatible fuse module types | Midget and Class CC |
| Product width | 9.1 mm |
| Product length | 44.7 mm |
| Product height | 24.4 mm |
| Product weight | 0.0168 kg |
| EAN / UPC | 782001356668 |
| Pack quantity | 1 |
The USFMAC11 is an auxiliary microswitch used with compatible Mersen USFM fuse modules to provide electrical interlocking, contactor control or status signalling when the fuse extractor handle is operated.
Early break means the auxiliary contact changes state before the fuse module opens, while late make means it returns to its normal state only after the fuse module has been fully closed.
Yes. It can be wired to an adjacent contactor so the contactor drops out before the fuse extractor disconnects the circuit.
The accessory is designed for compatible Mersen UltraSafe three-pole USFM modules for Midget and Class CC fuses.
No. The USFMAC11 is an auxiliary microswitch accessory and does not hold or provide overcurrent protection independently.
Mersen UltraSafe™ accessories are widely used by panel builders, OEMs and industrial maintenance teams to enhance fuse module safety, control integration and equipment reliability.
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2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...