Dehydrating breather
The principle of operation: simple and effective
Messko’s MTraB® maintenance-free dehydrating breather minimizes the ingress of moisture into the insulation liquid of transformers, on-load tap-changers and other electrical equipment filled with insulation liquids.
MTraB® is the ideal solution to the continuously increasing demands on quality and the reduction of life cycle costs of transformers and equipment.
Unlike conventional dehydrating breathers filled with silica gel or similar desiccants the silica gel in the silica gel chamber of Messko’s MTraB® is dehydrated by a sensor-controlled heater element that is installed. This minimizes the visual inspections, and the expensive, regular replacement of the drying agent is no longer necessary.
Many power companies have started retrofit programs and are replacing conventional dehydrating breathers with the Messko MTraB®. The MTraB® is the perfect solution for these retrofit projects, because it is available in many different flange designs.
During normal operation, the air flowing to the oil conservator is guided over the drying agent (silica gel) which then dehydrates the air. The degree of air moisture in the pipe is measured continuously with a moisture sensor and the results are forwarded to the electronic controller.
If the moisture content (% rF) of the air in the pipe exceeds a certain specified value, the self-regulating heater element in the silica gel chamber is activated. The water vapour escaping from the silica gel condenses on the specially designed bottom element and drips out of the stainless steel filter.
The temperature sensor is used by the controller to monitor the correct operation of the heating element. An additional heating system (optional) can also be used to prevent the filter system from freezing when outside temperatures are low.
The measured temperature value of the pipe line (dehydrating breather) is outputted by the controller as an analogue signal. Malfunctions of the controller or the heating system are indicated on a fail-safe, continuously powered contact.
All MTraB® highlights at a glance
With more than serveral tens of thousends installed units since its introduction to the market in 2003, the MTraB® dehydrating breather is contributing to the significant reduction of the life cycle costs for many customers around the world.
In addition, a transformer’s total operating reliability is increased since there is no more risk of moisture penetration if the conventional dehydrating breather is replaced too late.
Comparison
The right MTraB® type for every application
The following application table helps you to determine the appropriate MTraB® type with adjusted controller (α, β and γ) for use on your transformer.
α-controller: Recommended for use on on-load tap-changers, arc suppression coils and traction transformers. The dehydrating breather is only heated when needed (its state is monitored for hydration).
β-controller: Self-learning system which is recommended for use on transformers with cyclical loads (see table of applications). In addition to monitoring the hydration, a time window is determined during which the oil conservator exhales, and the dehydrating chambers are regenerated.
γ-controller: Recommended for special applications such as cavern transformers, furnace transformers and GSU transformers with non-periodical breathing behaviour.
If the moisture content of the air flowing in the direction of the transformer exceeds a specified value, the silica gel chambers are regenerated in sequence.