In oil-immersed transformers and resin impregnation systems, controlling the temperature of the process fluid is first and foremost a safety function, as well as a process requirement. Industrial thermostats perform this task: they sense the temperature through direct contact with the fluid and control the system’s heating, cooling or alarm devices accordingly. In these applications, they are typically mounted on tanks, vessels and process circuits, with configurations tailored to the distinct needs of electrical transformers and resin processing equipment.
Industrial Thermostats: Operating Principle and Available Types
The Elettrotec range of industrial thermostats includes mechanical devices: bimetal thermostats and liquid-expansion immersion thermostats, available with fixed or adjustable set points according to the system’s calibration needs. In immersion models, the sensing element measures temperature through direct contact with the fluid at the point specified in the system design, avoiding the delay that may result from measuring the outer surface of the vessel. The installation point and materials in contact with the fluid depend on actual operating conditions, especially where the system works with resins, under vacuum or with indirectly heated circuits. For applications requiring an adjustable temperature threshold, our TER adjustable immersion thermostat is available.
Thermostats for Transformers: Controlling Dielectric Oil Temperature
Thermal Protection and Temperature Control in Transformers
In oil-immersed transformers, the dielectric fluid provides electrical insulation and carries the heat generated by the windings to the outside. A thermostat installed directly on the transformer tank continuously monitors the oil temperature and allows the system to respond before critical conditions affect insulation and the transformer’s service life. Dielectric oil temperature control is therefore part of transformer thermal protection: when the preset threshold is exceeded, the thermostat can activate a cooling system or trigger an alarm.
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Thermostats for Resin Impregnation Systems
Dosing and Distribution: Controlling Resin Temperature Throughout the Circuit
In impregnation systems, resin temperature is a key process parameter: it affects fluid viscosity and cycle repeatability, with consequences for the quality of the finished product. Thermal control may involve several parts of the machine. Vacuum and vacuum-pressure impregnation systems can use heated autoclaves, including those heated with thermal oil, alongside resin storage tanks with independent heating and cooling systems. When different resins are used, each tank may require independent temperature control, while the autoclave heating cycle follows the process recipe for the product being impregnated. Resin recirculation and thermal conditioning also matter along the route to the autoclave. At these points, a suitably configured thermostat can initiate an action when a specified threshold is reached or signal a temperature deviation, working with the system’s temperature control and, where applicable, PLC supervision. The mounting position must be chosen according to the fluid to be monitored: the resin in the tank, where installation conditions permit, or the fluid in the heating circuit.
Custom Industrial Thermostats: From Component to Connection
What distinguishes our industrial thermostats for these applications is the scope for complete customization, from the component itself to its electrical connection. For each application, we work with the customer to define the most suitable temperature range, probe length and threaded process connection for the tank or vessel, as well as the wiring and connector required by the machine’s electrical system. Connection options include Deutsch DT06-2S (plug) and DT04-2P (receptacle), Delphi Metri-Pack 280 and AMP Superseal. These connectors are widely used in industrial machinery automation and are already found in transformer and resin impregnation systems. Upon request, our custom thermostats can also carry the customer’s logo, an option particularly suited to OEMs integrating the component into their own branded machines.
Conclusion
Elettrotec industrial thermostats for transformers and resin impregnation systems follow the same design approach as the rest of our industrial temperature control range: direct measurement in contact with the fluid, mechanical robustness, and configurable set points, dimensions and connections. For manufacturers of transformers and resin processing machinery, this means having thermostats designed around their application, without having to adapt the system to the component. To identify the most suitable configuration for your machine, explore the complete range of Elettrotec industrial thermostats or contact our technical department.