S16 Variant 5 is a dedicated motor protection relay. The relay measures the three-phase currents, the residual current component as well as the residual voltage.


Devices of the IED EP+ S16 series are designed to provide small-size, cost effective, simple solutions for feeder, motor and several kinds of back-up protection applications. These devices have predefined hardware arrangement and fixed standard configurations.


The relay is equipped with a USB 2.0 port on the front and a serial interface on the rear side. The front port is the engineering port where the user is able to change parameters etc. using the S16 Tool software. The rear port is only for SCADA connection.

General features

• Compact (16HP) housing
• Software-configurable secondary rated current for the phase and the residual currents
  (1-3CT channel rated current: 1 or 5A; 4th channel: 0.2;1;5A)
• Universal power supply (19.2 - 300 VDC; 80 - 255 VAC)
• Event recorder for up to 1000 events
• Free, user-friendly software tool
• High-speed, supervised TRIP contacts
• Built-in supervision
• Several mounting methods: Flush mounting; Semi-flush mounting; Din rail mounting
• Software-configurable rated voltage of the binary inputs
• Ready-to-use and straightforward handling
• Supported communication protocols: 
  
  • IEC 60870-5-101
  • IEC 60870-5-103
• 128x64 b/w LCD with white backlight
• 4x pushbuttons
• 8x three-color matrix programmable alarm LED indicators
• Three-color status LED

S16 Variant 5 is specifically designed to protect induction-type asynchronous motors.

The relay provides 4  current inputs and one voltage input for residual voltage measurement.

Despite the compact size the IED provides a wide range of protection functions which are based on current measurements: non-directional overcurrent , thermal overload , phase discontinuity, negative phase sequence protectiona, as well as breaker failure protection is available.

Based on the residaul current and voltage measuremnts the relay provides dicertional earth-fault protection. Moreover, the relay offers a number of other special motor protection and supervision functions that enable it to protect and run the motor more effectively and safely: motor thermal protection, motor startup supervision, asymmetry protection, loss of load protection, prolonged start locked rotor protection.