Reliable power for a sustainable world
Current Range: 32 - 120 A

Static Transfer Switch


Master Switch Single-phase (MMS) is part of the Master Switch range and offers solutions suitable for protecting singlephase loads with different power ratings.
MMS is available in three sizes - 32, 63 and 120 A - and is, therefore, able to satisfy various requirements for the protection of single-phase loads.

Master Switch Monofase MMS


  • Operating flexibility

  • Load protection

  • Complete diagnostics

  • Hot Swap function

Brochures and data sheets

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Master Switch STS Single-phase

32-63-120 A Static Transfer Switch

Technical specifications of the model

Flexibility of use
All MMS versions are designed with criteria that facilitate on-site installation as well as diagnostics, control and maintenance operations. All models are equipped with a manual bypass and the hot-swap function allows for rapid corrective interventions by non-specialised personnel in the event of faults.

Load protection 
With MMS transfer switch loads are protected against critical environmental situations and mains power interference. Microprocessor control and the use of thyristor static switches ensure continuous monitoring of the power supply sources and reduced switching times between the two sources in the event of a fault.  
The constant monitoring of the output current allows for the rapid identification of any short circuit currents in the consumers, preventing short circuits from propagating to other loads.
MMS is equipped with thermal-magnetic protection for the two sources, ensuring rapid intervention in the event of faults and integrated back feed protection.  
MMS ensures switching times between the two power sources of less that a quarter of a cycle, both in the event of manual switching and in the event automatic switching triggered by a fault in the power source.

Complete diagnostics 
All MMS versions are equipped with 32-character LCD displays and control panels with multi-function keys.  
This allows for rapid and intuitive monitoring of supply readings, switch status and environmental conditions. MMS is equipped with three standard programmable dry contacts, an input for emergency shutdown, a RS232 serial connection and a slot for housing the expansion board, thus ensuring complete availability of interface solutions for remote control and monitoring.