Wireless measurement. Greater installation flexibility.
SILENTVAR supports wireless measurement of electrical parameters, reducing the need for additional measurement wiring. This makes it easier to choose the compensator’s mounting location and adapt the system to existing installation conditions.
The solution is particularly useful where modifying the installation is difficult, costly or undesirable, including heritage buildings.
The system also supports wired measurement using a conventional current transformer or a split-core current transformer with a 5 A secondary output.
Silence is part of the technology
SILENTVAR operates without fans or the characteristic sounds of compensation step switching.
Quiet operation is particularly valuable in urban spaces, commercial facilities, offices and other locations where noise from technical equipment is undesirable
Compact controller. Flexible component positioning.
The SILENTVAR S controller measures 190 × 39 × 160 mm. Its slim enclosure and DIN rail mounting capability simplify installation in cabinets with limited space.
Separate mounting of the controller and reactor allows the components to be positioned to suit the cabinet layout, which is particularly useful when upgrading existing switchboards.
The reactor design enables multi-step reactive power regulation. Depending on the configuration, the system can work with additional reactors to extend the available compensation range
Automatic. Precise. Without ongoing user intervention.
SILENTVAR monitors installation parameters and continuously adjusts the compensation level as the load changes.
The system includes:
- automatic reactive power compensation,
- SMART operating mode,
- reactor self-calibration,
- single-step compensation tuning,
- adjustment of the tan φ factor,
- time hysteresis between regulation step changes,
- overcurrent protection,
- automatic thermal protection,
- reactor temperature and compensation status alarms.
During normal operation, the device requires no ongoing user intervention.
Ready for integration
SILENTVAR supports remote parameter reading, setting changes and integration with external automation and monitoring systems.
Available communication options include:
- Wi-Fi,
- Ethernet,
- Modbus,
- REST API.
A built-in display provides local access to network and compensation parameters.
The device can work with the ASTgsm LTE control and monitoring system from AST System, enabling reactive power compensation to be integrated with lighting infrastructure monitoring
Benefits
The SILENTVAR S system helps to:
- reduce reactive energy charges,
- automatically adjust compensation to the current load,
- reduce the need for manual adjustment,
- position the controller and reactor flexibly within the available space,
- simplify upgrades to existing cabinets and switchboards,
- reduce additional measurement wiring,
- provide quiet, fanless operation,
- remotely monitor parameters and change settings,
- expand the system with additional reactors,
- integrate compensation with infrastructure management systems.
Key features
- Operation in single-phase and three-phase installations, depending on the configuration.
- Automatic reactive power compensation.
- SMART operating mode.
- Wireless parameter measurement.
- Wired measurement using a current transformer with a 5 A secondary output.
- Up to 43 regulation steps, depending on the configuration.
- Compensation adjustment range of 12–100%.
- Reactor self-calibration.
- Single-step compensation tuning.
- Adjustment of the tan φ factor.
- Time hysteresis between regulation step changes.
- Support for additional reactors.
- Display of network and compensation parameters.
- Remote parameter reading and setting changes.
- Wi-Fi, Ethernet and Modbus communication.
- REST API.
- Overcurrent and thermal protection.
- Reactor temperature and compensation status alarms.
- Quiet, fanless operation.
- Separate controller and reactor design.
- Vertical or horizontal installation and DIN rail mounting.
- Compatibility with the ASTgsm LTE control and monitoring system from AST System, enabling reactive power compensation to be integrated with lighting infrastructure monitoring.
Technical specifications
Power supply
- Supply voltage: 230 V AC
- Voltage tolerance: −10% / +15%
Compensation and control
- Installation type: single-phase or three-phase, depending on the configuration
- System compensation output range: 35–7600 var, depending on the configuration and reactors used
- Number of regulation steps: 10–43, depending on the configuration
- Compensation adjustment range: 12–100%
- SMART operating mode
- Adjustment of the tan φ factor
- Reactor self-calibration
- Single-step compensation tuning
- Time hysteresis between regulation step changes
- Support for additional reactors
Measurement
- Wireless remote parameter measurement capability
- Wired measurement option
- Support for conventional or split-core current transformers with a 5 A secondary output
- Local parameter readings on the display
Communication
- Wi-Fi
- Ethernet
- Modbus
- REST API
- Remote parameter reading and setting changes
- Compatibility with the ASTgsm LTE system from AST System
Protection and alarms
- Overcurrent protection
- Automatic thermal protection
- Reactor temperature alarm
- Compensation status alarm
Mechanical specifications
- Design: separately mounted controller and reactor
- Protection rating: IP20
- Controller dimensions: 190 × 39 × 160 mm
- Reactor dimensions: depending on the selected configuration
Installation
- In control and lighting cabinets
- Controller suitable for DIN rail mounting
- Vertical or horizontal orientation
- Separate positioning of the controller and reactor
Operating conditions
- Operating temperature: −20°C to +60°C
Five versions. One system.
SILENTVAR S is available in five configurations with different compensation outputs and numbers of regulation steps.
| Model | Compensation output | Number of regulation steps | Controller dimensions |
| S 320/10 | 320 var | Up to 10 | 190 × 39 × 160 mm |
| S 720/10 | 720 var | Up to 10 | 190 × 39 × 160 mm |
| S 1600/10 | 1600 var | Up to 10 | 190 × 39 × 160 mm |
| S 1520/21 | 1520 var | Up to 21 | 190 × 39 × 160 mm |
| S 3600/21 | 3600 var | Up to 21 | 190 × 39 × 160 mm |
The dimensions shown apply to the controller only. The reactor is mounted separately and requires additional installation space.
Depending on the configuration, the system can work with additional reactors to extend the available compensation range. The maximum system compensation output is 7600 var with an appropriately selected configuration.
Custom versions with individually selected reactor designs, compensation outputs and numbers of regulation steps are also available, including configurations with up to 43 regulation steps.
Applications
- Street lighting control cabinets — reactive power compensation in new and existing lighting installations.
- Switchboard upgrades — flexible positioning of the controller and reactor, with reduced measurement wiring.
- Commercial facilities and public buildings — automatic reduction of reactive energy charges in installations with suitable load characteristics.
- Heritage buildings — reduced need for additional measurement wiring.
- Infrastructure requiring remote supervision — integration of compensation parameters with monitoring and automation systems.
Select the right compensator for your installation
The output and configuration of the SILENTVAR S system should be selected based on an analysis of the installation’s electrical parameters, load characteristics and reactive energy billing arrangements.


