Electromechanical Voltage Stabilisers

Our electromechanical (EM) Voltage Stabilisers deliver the most cost effective and efficient way to ensure a stable, undistorted mains supply for most applications.

Here are some of the many benefits:

  • Custom made to suit any application, at any size and with any option required
  • Thousands of models ranging from 1kVA to 4mVA
  • Single or three-phase options available with input ranges from ±8% to ±40%
  • Supplied with a range of digital communications options
  • Optional bypass systems
  • Standard indoor IP20 range and outdoor IP54 range up to 4mVA


Light Industrial

Our Light Industrial EM stabiliser is built on 75 years of stabiliser manufacturing heritage and tens of thousands of installations world-wide. Complete with input MCCB, test points and metering, the EM system is compact and simple to install, offering reliable performance coupled with simple servicing and fully adjustable independent phase regulation.

Commercial Voltage Stabilisers

High powered product range of Electromechanical Voltage Stabilisers combining Watford Control's unique "Twin Track" Rotavolt technology, with wide correction ranges of up to ±40%, easy to maintain and simple to operate.

Our EMS stabilisers are available across the full power range up to 4000kVA in either single or three phase configurations. Available with standard correction ranges of ±40% and an output accuracy of 0.5%, the EMS range offers a reliable and cost effective solution to your power quality needs.

Introducing EnviroVolt

Introducing the EnviroVolt Voltage Stabiliser from Watford Control, a revolutionary range of power correction solutions designed to transform the way you control and stabilise electrical power. With its unparalleled reliability, exceptional performance, and attractive pricing, the EnviroVolt is set to redefine the industry standards within the 50kVA - 300kVA space.

One of the standout features of the EnviroVolt is its customer-selectable asymmetric correction range. With options up to 50% correction range (subject to power rating), giving you the flexibility to tailor the correction range to meet your specific needs. This adaptability ensures that the EnviroVolt can be adjusted to match everchanging site conditions, ensuring optimal power stability and efficiency.


Watford Control is widely regarded as the world leader in IP00 Voltage Stabiliser solutions for the specialist power industry. Our bespoke solutions are used by Europe's leading vendors to integrate into their systems as part of their customer offering, these include power conditioning systems with Isolation Transformers, all in either two, three or four wire systems.

Our EM system is the most compact stabiliser on the market. It is available in a standard single or 3 phase configuration, with ranges from 44kVA/±30% to 100kVA/±15%
  • Correction range up to ±30%
  • Output accuracy 0.5%
  • Adjustable Output Voltages 220V - 240V
  • Power Ratings up to 100kVA
  • Standard Warranty 2 Years
Our specialist stabilisers are available across the full power and correction range, with multiple configuration types from IP00 to IP54 or installed in a customer's own supplied enclosure . . .
  • Correction range up to ±40%
  • Output accuracy 0.5%
  • Adjustable Output Voltages up to 690V
  • Power Ratings up to 4000kVA
  • Standard Warranty 2 Years

Compare Our Solutions


Cost Option

Not Available

OptionLight IndustrialCommercialEnvirovoltSpecialist
Input Breaker
Output Breaker
Class I Surge Suppression
Class II Surge Suppression
M.O.V Transient Suppressors
Analogue Voltmeter
Analogue Ammeter
Digital Output Meter
Digital Output Meter with Current Monitoring
Bypass Switch
Under / Over Voltage Protection
Phase Failure / Sequence Monitoring Relay
Under / Over Frequency Relay
Soft Start *
Asymmetrical Input Range
Voltage Test Sockets
Three Wire Option
Isolation Transformer

* On ±15% Upwards