Contatti internazionali


Innovative motor-drive solutions
with integrated monitoring.

Your benefits at
a glance

  • Innovative drive for tap changers
  • Benefits during the manufacture and operation of power transformers
  • Smart monitoring and control as the basis for smart transformers
  • Modular scope of function, individual expansion possible
  • Condition-based maintenance
  • Easy to operate, intuitive graphics interface


Key improvements – maximum customer benefit

In the ETOS® TD drive for tap changers, the energy is made available precisely where it is needed – i.e. at the tap-changer cover. The drive commands generated in the control cabinet are transmitted via a cable connection to the motor installed above. This eliminates the need for a rigid drive shaft connection and the complex and time-intensive task of installing it. What's more, the precise motor torque delivered to the driven tap changer guarantees maximum safety when switching loads. This is because, in addition to the conventional drive function, the smart drive can check all key parameters using the OLTC PreCheck function (e.g. overcurrent, oil temperature and oil level) before a switching operation.

ETOS® TD – the integrated motor-drive solution

The ETOS® TD is factory-fitted with our very own ISM® technology (Integrated Smart Module). This electronic automation platform is particularly well suited to the special conditions of energy technology. As well as controlling the tap-changer drive, this platform lets you record and evaluate all relevant operating data / sensors from the power transformer. The simple connection of transformer sensors to the control system (SCADA) makes for fast commissioning and even the integrated visualization does not require the installation of any additional software.



This greatly reduces the amount of wiring needed during installation and significantly cuts costs compared to a conventional connection method. This allows you to plan how you operate, service, and replace your equipment in a more efficient and targeted manner. Providing you with intelligent operational management and optimized asset management.


Open system. ETOS® functions.

Efficient control and monitoring of transformers.

  • Innovative top drive or proven drive technology with mechanical drive linkage
  • Integrated motor current monitoring and monitoring of tap position
  • Conforms to IEC 60214-1:2014
Standard functions (contained in every ETOS® design)
  • Status monitoring of the protective devices (e.g. RS2001, Buchholz relay, PRD)
  • Monitoring the oil temperature
  • System voltage, load current, frequency, load factor, active power, reactive power, apparent power
  • Hot-spot calculation in accordance with IEC 60076-7 or ANSI/IEEE C57.91
  • Calculation of aging rate and loss-of-life
  • Tap position capture
Advanced functions
  • Capability of transformer to handle overload in the short or long term with live calculation and simulation of overload forecasts in accordance with IEC 60076-7 or ANSI/IEEE C57.91
  • Calculation of the bubbling temperature
  • Calculation of paper moisture content
Cooling system monitoring
  • Number of starts per cooling level
  • Operating time per cooling level
  • Monitoring of Rth and cooling efficiency
Cooling system control
  • Switching points, hysteresis and delay times adjustable to your needs
  • Various control algorithms (Periodic cooling group activation or predictive cooling)
  • Fail-safe mode
  • Optional as frequency-controlled cooling system control for increased performance and lower fan wear
Standard functions
  • Status monitoring of the motor-drive signals
  • Maintenance recommendations and maintenance interval calculation for OILTAP® and VACUTAP®
  • Calculation of contact wear for OILTAP®
  • Tap-position statistics for the OLTC (number of tap-change operations/tap, duration per tap)
  • Monitoring of OLTC oil temperature
Advanced functions
  • Motor current index in accordance with IEEE PC57.143
  • For ETOS® ED: OLTC torque monitoring
  • Online recording of up to ten corrosive gases, relative moisture in oil and relative overall gas content
  • Configurable limit value for each gas
  • Diagram of the measured values
  • Measured value memory
  • Universal 4…20mA or Modbus RTU Interface for capturing the DGA sensor signals
  • Standard evaluation methods in accordance with Duval, Rogers, Dörnenburg and IEC 60599
Standard functions
  • Measurement of system voltage and load current (single- or three-phase)
  • One desired value
  • Voltage regulation with linear delay time T1
  • Status of the motor-drive unit
Advanced functions
  • Various types of desired-value setting (three or fi ve desired values, TAPCON® Dynamic Setpoint Control, desired-value setting via analog value, raise/lower pulse, desired value via BCD)
  • Automatic voltage regulation with linear or integral time characteristics and two delay times T1 and T2
  • Parallel operation via CAN bus (up to 16 transformers)
  • Line drop compensation (RX or Z compensation)
  • Monitoring of bandwidth
  • Function monitoring
  • Limit-value monitoring
  • Monitoring of changes in C1 capacitance
  • Monitoring of the dissipation factor (tan δ)
  • System voltage
Additional functions
  • Freely programmable digital and analog inputs and outputs
  • Open programming with function blocks possible with TPLE function
  • Optional: Integration of functions in a motor-drive unit for the on-load tap-changer (side drive or innovative top drive)
  • Optional: Integration of the complete control including power unit of a conventional cooling system. Can also be combined with the advantages of intelligent cooling system control, such as predictive cooling (on request)
  • Visualization using web server (SVG and HTML 5) included as standard for various end devices
  • IEC61850 Ed. 1 and Ed 2. MMS, and GOOSE
  • IEC60870-5-101, -103, -104
  • DNP3
  • Modbus TCP, RTU, ASCII
  • Remote maintenance support