GammaSit System
Gas Adaptive and High Modulation solutions for condensing appliances give always the maximum efficiency in the use of energy with a  clean combustion and an easier integration with Renewable Energy Sources.
The GammaSit is a new family of gas and combustion control systems specifically designed for boilers using premix burners. These kinds of appliances represent the state of the art in domestic heating and therefore the appliance manufacturers are deeply involved in research for higher performance, simpler assembly and installation techniques and design optimization.
The new GammaSit system consists of a multifunctional control device (gas valve) and an electronic device (electronic burner control system).  The burner control system is completed by the traditional “brushless” fan for the combustion air.
The common platform for the gas control consists of two automatic shut-off valves (double shut-off function) and a modulating servo pressure regulator, while the common platform for the electronic control includes the ignition and flame detection functions as well as the command of all appliance electrical devices in order to control the water temperature at the boiler’s output (sanitary and/or heating). The electronic control board structure and the components used allow a significant customization of the requested control functions and the connection of auxiliary interfaces. 

The GammaSit family includes 2 systems:
GammaSit GA “Gas Adaptive”
The 849 Sigma gas control is customized with adoption of a gas pressure modulator with electrical command.
In this system the flame detector (electrode) is additionally used as a combustion sensor for the burner. The electronic control device in combination with the combustion control function follow a controlling algorithm which regulates the gas valve electrical modulator and the fan.

GammaSit HMGA “High Modulation, Gas Adaptive”
The 849 Sigma gas control is customized with a gas pressure modulator with electrical command and an electronic differential pressure sensor.  These 2 devices connected to the electronic control assure the modulation function.
The electronic control is customized with a valve outlet pressure regulation “loop” made through the pressure sensor and the gas valve modulator, in order to get a wide modulation range of the appliance. The electronic control also uses a combustion sensor, which carries out the additional burner combustion control function by controlling the modulation and the fan at the same time, following a specific regulation algorithm.
The control system is completed by the usual air-gas mixer.

The 849 Sigma Benefits:
Wider range of product configurations:
- Electrical supply: AC/DC, low and mains voltage
- Gas Capacity: 60 kW
- Temperature Range: -15/70°C

Well Proven Reliability:
- More than 80% of components/functions have a 10 years field history inside Sigma Family
- Quicker customer validation of the gas control

MAIN FEATURES

GAS Adaptive
The GammaSit adapts automatically to every kind of gas.
The system offers the following features  when installed:
- Combustion always in optimal conditions with high efficiency and low emissions
- An easy installation
- Wide country application with the same system

HIGH Modulation
In low heat demand conditions, for instance during the night, GammaSit allows the boiler to function up to a tenth of its maximum power. When required, for example during the day when the sanitary water is needed, GammaSit brings the boiler quickly to the highest requested power.
Features:
- On-Off appliance cycles reduction with lower standby losses and increased  seasonal efficiency
- Longer lifetime for the components and the appliance
- Easy integration on heating installations using Renewable Energies Sources (solar, heat pumps)

HIGH Precision
Frictionless electromagnetic linear actuator with negligible hysteresis
Features:
- Electronic offset calibration
- Offset  dynamically adjustable depending on working conditions
- Preventive maintenance