Dry-type transformer manufacturersThe safe operation and service life of dry-type transformers depend to a large extent on the safety and reliability of the insulation of the transformer wrapping components. The heat and cold of the package components exceed the heat and cold of the insulation and damage the insulation, which is one of the main reasons for the normal operation of the transformer. Therefore, it is very important to monitor and alarm the working cold and hot of the transformer.

⑴ Automatic fan control: The hot and cold signals are measured by a Pt100 thermistor embedded in the hottest part of the low-voltage wrapping member. When the transformer load increases, the working heat and cold rise. When the cold and heat of the wrapping member reaches 110 ℃, the system automatically starts the fan for cooling; when the cold and heat of the wrapping member drops to 90 ℃, the system automatically stops the fan.

(2) Overheat alarm and trip: Obtain the cold and heat signal of the wrapped member or iron core through the PTC nonlinear thermal resistance embedded in the low-voltage wrapped member. When the cold and heat of the wrapped components of the transformer continue to rise, if it reaches 155 ℃, the system will output an over-temperature alarm signal; if the cold and heat continue to rise to 170 ℃, the transformer will no longer be able to operate. The overtemperature trip signal must be sent to the secondary protection circuit to quickly trip the transformer.

(3) Cold and hot display system: The cold and hot change value is measured by the Pt100 thermistor embedded in the low-voltage wrapping component, and the cold and hot of each phase wrapping component are directly displayed (three-phase inspection and large value display can record historical high cold and hot). High cooling and heating can be output as 4 ~ 20mA analog quantity, if necessary, it can be transmitted to a remote computer (distance up to 1200m)

Protection mode:Dry-type transformer manufacturers said,Generally, IP20 protective enclosure is selected to prevent solid foreign bodies with a diameter of more than 12mm and small animals such as mice, snakes, cats, birds, etc. from entering, which may lead to short circuits, power outages and other malignant faults, and provide safety barriers for live parts. If the transformer must be installed outdoors, an IP23 protective enclosure can be selected. In addition to the above IP20 protection function, it can also prevent water from falling into the transformer at an angle of 60 ° to the vertical. However, the IP23 enclosure will reduce the cooling effect of the transformer, so you should pay attention to reduce its working effect when choosing.

Overpressure effect: the overpressure effect of dry-type transformer is related to the environmental cold and heat, the load conditions before overpressure (initial load), the insulation and heat dissipation of the transformer, and the heating time constant. If necessary, the overload curve of the dry-type transformer can be obtained from the manufacturer. How to use its overpressure effect?

   Dry-type transformer manufacturers said,The transformer capacity can be appropriately reduced during selection and calculation: fully consider the possibility of short-term impact overpressure of some steel rolling, welding and other equipment-try to use the strong overpressure effect of dry-type transformers to reduce the transformer capacity; For some places with uneven load, such as residential areas mainly used for night lighting, cultural and entertainment facilities, and shopping malls mainly used for air conditioning and day lighting, the overpressure effect can be fully used to appropriately reduce the transformer capacity, the main operating time is full load or short-term overpressure.