Line Protection with EMU-1

Core function of the EMU-1 circuit breaker is to protect the line against a short circuit while being able to handle inrush currents to the load. For this purpose, different approaches are implemented in parallel and independent of each other in the EMU-1 module. The design is based on firmware dependent and independent sections to guarantee a highly reliable functionality.

Additionally, the EMU-1 module protects the load against the following faults:

  • Current: User settable nominal current flow ( from 0.1 to 16 Amperes)
  • Voltage: Over- & Under voltages ( configurable between  85 bis 250 Vac )
  • RCD: Line & Return path unbalanced current flow ( configurable amount and delay)


Firmware independent circuit-breaker

The instantaneous current (maximum value) to the load is compared to a fixed target value. Exceeding this target value will lead the EMU-1 module to automatically break the circuit in less than 0.2 milliseconds. This protection is not only independent of the firmware, but also independent of the AC line period. The maximum allowed current amount through the EMU-1 is determined by the maximum allowable current through the switching transistors within one millisecond and is usually between 60 to 100 amperes. Once triggered, the load will remain disconnected until the firmware handles the fault as per user configured settings automatically or a manual release by the user resets the fault condition.

In an emergency case an internal fuse guarantees the circuit breaking action, if all builtin electronic and firmware driven protections fail.

Firmware controlled actions

The EMU-1 circuit breaker firmware offers a number of adjustable monitoring options, which may lead into a circuit-breaking action or generating an event. Each of these monitored parameters can be individually specified as nominal or absolute values. Exceeding target values in any direction may trigger the defined protecting action. Events can trigger not only internal actions, but also external actions linked to the EMU-1 via any of the existing communication paths. Furthermore, any monitored fault can be bind to an individual duration before the specified action is executed. The amount of the duration starts at 10 milliseconds and in some cases the duration can be set up to several seconds.

Below you can find a list of adjustable parameters for monitoring:

  1. Current to the load: 0.1 to 16 Ampere
  2. Load current difference between line and return path: 10mA to 1000mA
  3. Line voltage: 85 Vac to 250 Vac
  4. Power (W, VA, VAR) 
  5. Energy (Wh, VAh, VARh)
  6. Cos φ (0 to 1)
  7. Frequency (45 to 60 Hz)

How to buy EMU-1

This module will be available for purchasing by the end of year.  If you are interested to get one early, you can register yourself below to be informed as soon as the product is available.