Superior technology. Compelling economics.


Product description

In distribution grids, non-voltage regulation transformers, which cannot respond to changes in voltage under load, are generally used. ECOTAP® VPD® turns these fixed distribution grid transformers into regulating transformers which keep voltage stable in public, industrial, and private distribution grids. They compensate for fluctuations in the medium voltage and respond dynamically to changes in feed-in and load at the low-voltage level.

This opens up new opportunities, not just for utilities but also for industrial companies or operators of wind turbines, all of whom stand to gain from distribution grid transformers regulated with ECOTAP® VPD®.


ECOTAP® VPD® combines the know-how that MR has accumulated over the decades in vacuum on-load tapchangers of the high-speed resistor-type technology with the experience in voltage regulation distribution transformers gained around the globe since 2012 through working with transformer manufacturers and operators. This experience was used as the basis for developing the next ECOTAP® VPD® generation with anywhere from 9 to 17 on-load tap changer positions, which ensures a large regulating range and fine tuning of tap changes.


Technical Data

On-load tap-changer ECOTAP® VPD® III 30 ECOTAP® VPD® III 100
Number of phases 3
Application At any point in the winding
Permitted transformer types Free-breathing with oil conservator
Totally oil-filled hermetic transformers (without gas cushion)
Free breathing with air cushion only in combination with a special
variant of the ECOTAP® VPD® (on request)
Max. rated through-current 30 A 100 A
Max. rated step voltage 825 V
Max. number of operating positions 9 operating positions without change-over selector
17 operating positions with change-over selector
Highest voltage for equipment 36 kV, 40,5 kV
Rated frequency 50/60 Hz
Max. number of tap-change operations 500.000
Permissible absolute pressure during operation 0,7…1,4 bar


Motor-drive unit
Runtime per tap-change operation approx. 420 ms
Shortest gap between tap-change operations 3 s
Permissible ambient temperature during operation -25 °C ... +70 °C
Protection class IP54
Installation site Indoors, outdoors


Control unit
Permitted voltage range 100...240 VAC, 50/60 Hz
Note: Measured voltage is supply voltage  
Power consumption Max. 345 VA
Internal fuse (F1) Micro-fuse, 6,3x32 mm, min. 250 V, T4A
Permissible ambient temperature during operation Continuous operation: -25 °C...+50 °C
Brieflly (maximum of 2 h per day): -25 °C...+70 °C
Protection class IP30
Installation site Indoors, also suited to outdoor use in separate housing