Voltage regulation
Voltage Stabilizers & Voltage Controllers
Tap-changing stabilizers and adjustable voltage controllers up to 500 kVA.
- Supply
- Single or three phase, 50 Hz
- Technology
- Tap-changing or variable transformer
- Control
- Automatic, manual or motorised
Have a different requirement? Share your application and preferred configuration.
Made for the application.
This class covers two non-servo products. Automatic voltage stabilizers switch between transformer taps with relays or thyristors to keep the output within a stated band, and suit dedicated loads and smaller supplies. Voltage controllers use a manual or motorised variable transformer to set an adjustable output voltage for heaters, test benches and process equipment, up to 500 kVA.
Typical application contexts
- Dedicated machines and equipment circuits
- Air-conditioning and refrigeration equipment
- Heater, oven and furnace power adjustment
- Test benches and laboratories needing adjustable AC
- Small commercial premises and residences
- Process equipment with a set voltage requirement
Tap-changing correction
Relay or thyristor switching moves the output between transformer taps, which keeps compact units simple to install and maintain.
Adjustable output
Voltage controllers set the output anywhere across their range, for heaters, test benches and process loads that need a chosen voltage.
Time-delayed restart
After a supply interruption the output returns only after a set delay, which protects compressors and motors from rapid restarts.
Manual or motorised adjustment
Controllers are offered with a handwheel or a motor drive; the motorised version can take raise and lower commands from a panel.
Formats by rating
Smaller units are wall mounted; larger units are floor standing with air or oil cooling selected for the site.
Technical specifications
Typical values for the product class. The ratings, options and operating conditions for your equipment are confirmed during engineering review and stated in the quotation.
| Parameter | Value | Condition |
|---|---|---|
| Rating range | Up to 500 kVA | Tap-changing stabilizers typically 1–100 kVA; voltage controllers up to 500 kVA |
| Input voltage window | 170–270 V AC single phase; 340–480 V AC three phase | Stabilizers; voltage controllers take a nominal 230 or 415 V AC input |
| Output voltage | 230 or 415 V AC fixed (stabilizers); adjustable, typically 0–270 V or 0–470 V AC (controllers) | Single phase and three phase respectively |
| Output accuracy | Typically ±2–5% of set voltage | Tap-changing stabilizers; depends on the number of taps |
| Correction time | Typically under 1 s per tap step | Tap-changing stabilizers |
| Frequency | 50 Hz | Operation typically within 47–53 Hz |
| Cooling | Air cooled; oil cooled for higher ratings | Selected against rating and ambient conditions |
| Efficiency | Typically 95–98% | At rated load and nominal input |
| Control | Automatic (stabilizers); manual handwheel or motorised (controllers) | Remote raise and lower for motorised controllers by assessment |
| Protection | Under-voltage and over-voltage cut-off; overload trip; time-delayed restart | Thresholds and delays stated for each unit |
| Ambient temperature | 0–45 °C | Derating above 45 °C |
| Enclosure and mounting | Powder-coated sheet steel, wall mounted or floor standing; IP20 or IP21 indoor | Mounting depends on rating |
| Metering and indication | Digital or analogue voltmeter; status lamps | Output ammeter by assessment |
Documents & next steps
PDFVoltage Stabilizers & Voltage Controllers datasheetTypical specifications · Up to 500 kVADrawings and documents for a specific order are agreed during engineering review.
For a useful first conversation
- Input supply range and required output voltage or adjustment range
- Load type, duty pattern and operating environment
- Control, protection, indication and interface expectations
- Installation, maintenance and access constraints
Common questions
A little context before you enquire.
Should I choose a tap-changing stabilizer or a servo stabilizer?
A tap-changing stabilizer corrects in steps and suits dedicated loads that tolerate a few per cent of variation. A servo stabilizer corrects continuously and holds a tighter output, which suits larger and more sensitive loads.
What is a voltage controller used for?
A voltage controller sets an adjustable output voltage rather than holding a fixed one. Typical duties are heater and furnace control, motor and lamp testing, and process equipment that needs a chosen voltage.
Can a voltage controller run continuously at full current?
Continuous current at low output settings depends on the variable transformer and brush rating. State the duty at each operating setting so the rating can be checked.
What information is needed for selection?
The connected load, the input voltage range or required output range, the duty pattern and the installation location. Recorded supply measurements help where they are available.
Where it is used
Application pathways that commonly start with this product class.
- IndustrialProduction facilities and process equipment
- Residential & architecturalHomes, buildings and integrated projects
