Standard accessories
- 4 bidirectional wheels
- 2 grounding terminals
- 1 identification plate
- 2 or 4 lifting lugs (according to the rating power)
- 4 connections for haulage
- No load tap changer
Accessories upon request
Safety devices
Oil temperature indicator
Where: All types of transformers
Description: Device used to measure the top oil temperature in the tank by a sensor. It can be provided with 2 or 4 SPDT switches.
Winding temperature indicator
Where: All types of transformers
Description: Device used to measure the winding temperature in the liquid immersed transformers by indirect way using thermal image tecnology. It can be provided with max 4 SPDT switches.
Buchholz relay
Where: Transformers with conservator
Description: This device intercepts and collects any gas bubble coming from the inner side of the transformer (indicating short circuit or other inner faults) and/or signals any oil leakage from the tank, giving an alarm signal or tripping one. There are different options according to the dimension of the pipe connecting flange. It is possible also to connect a gas sampling device with Buchholz relay to collect the gas for the analysis.
Air breather
Where: Transformers with conservator
Description: The aim of this device is absorbing the humidity air that the transformer sucks during the thermal contraction of the liquid in order to guarantee a better dielectric capacitance. There are different dimension and connections according to the oil contained in the conservator; when the salt becomes green means it is satured by humidity.
Oil level indicator
Where: Transformers with conservator
Description: This device gives a visual signal of the oil level in the conservator. There are different options according to the dimension and the type of conservator; it is also possible to signal the max and/or min oil level by switches.
Pressure relief device
Where: All types of transformers (smaller PRD without contacts can be available also for hermetic transformers)
Description: In case of sudden and violent internal short circuit the insulating liquid produces a large volume of gas that should be evacuated in order to avoid the explosion of the transformer. By means of PRD it is possible to evacuate the oil. There are different types with dimensions according to the oil quantity contained inside the tank of the transformer; it is also possible to signal the opening of the PRD by switches placed on its cover.
DGPT2 or RIS
Where: Hermetic transformers
Description: Device used for keeping under control pressure, temperature and level of the liquid inside the transformer tank.
Shutter valve
Where: Power transformers with conservator
Description: Device used to block the escape of oil coming from conservator in case of leakage in the transformer tank. It is interposed between the Buchholz relays and the conservator. It can be set with alarm and trip signals according to the flow valve setting.
Flow indicator
Where: Power transformers with conservator
Description: Device used to control of the oil flow out of the pumps on transformers with forced oil cooling equipment. It is used also in water cooled transformers. A small flow indicator is also available for distribution transformers.
Antivibrating pads
Where: Distribution transformers
Description: Accessories to be assembled under the wheels in order to reduce noise and structural resonances.
Marshalling box + Electrostatic screen
Where: Distribution transformers
Description: Marshalling box centralizes the auxiliary services and protects the terminal board.
Electrostatic screen allows a strong reduction of the capacitive coupling between MV and LV windings and also a reduction of overvoltages transferred among the same windings.
Overvoltage protection devices
Where is used: All type of transformers
Description: The aim is to protect the regulating winding. There are 2 possibilities: using surge arresters located close to the terminals as much as possible or using spark gaps on the bushings.
Electronic safety devices
To have an instant control on all essential parameters of the transformer SEA can provide part of the accessories with
Analog output 4÷20 mA or RS485 digital output Modbus protocol
Please contact our Sales department for additional informations
Bushings
Elastimold bushings
Where: Distribution transformers
Description: The plug connection allows a very rapid connection of the cable to the transformer and can be touched when the transformer is under voltage. They are manufactured according to the Standards EDF HN 52 S 61 - CENELEC EN-50181-50180 - IEEE 386-1995 - UTE C 66-555 - DIN 47636. Always specify in your request the type of rapid connection desired.
Busbars
Where: Distribution transformers
Description: Suitable for indoor and outdoor application with protective cap. They are manufactured according to the Standards EN 50387, ENEL DJ1107-1109 and BS 2562/1979.
Inner cone bushings
Where: Distribution transformers
Description: Suitable for indoor and outdoor application with protective cap. They are manufactured according to the Standards DIN 47637 - ENEL DJ1111 and DJ1108.
Porcelain bushings
Where: All type of transformers
Description: Oil to air bushings used to bring the connection from the transformer insulation medium to the external insulation medium. Suitable for voltages up to 45 kV.
Elbow bushings
Where: All type of transformers
Description: These connecting pieces are fitted instead of the porcelain bushings on the medium voltage side of distribution or power transformers.
Composite bushings
Where: All type of transformers
Description: Oil to air bushings used to increase general safety level; it is possible to use such bushings made of composite material instead of porcelain in order to guarantee no oil leakages, no risk of fire, possibility to be assembled horizzontally and control of partial disharges. They are interchangeable with porcelain bushings in compliance to EN 50180 and suitable for use according to C5 corrosiveness class with reference to ISO 12944. Remark: this bushing is not a condenser bushing but it can provide the voltage signal through a capacitive socket.
Condenser bushings
Where: Power transformers
Description: Bushings suitable for voltages from 25 to 52 kV or higher. It is possible to get an active control of voltage distribution between the central high voltage lead and the external flange.
High current bushings
Where: Power transformers
Description: Bushings up to 30 kA. Their aim is conducting heat by the central massive conductor.
Automatic voltage regulator
AVR
Where: Power transformers with OLTC
Description: This device is used to mantain a stable voltage on the load side of the power transformer when the network conditions are varying. AVR measures the control voltage of the transformer and regulates the on load tap changer consequently. 3 functions in 1 device: measuring, controlling and regulating.
Cable boxes
Where: Distribution transformers
Description: Boxes used to protect bushings according to the International Protection rating.
SEA can offer the following configurations:
Type A
Standard design: IP 41
Option 1: Cable box with rating IP 55 (for higher ratings please contact us)
Option 2: Internal busbars for cable incoming from below
Option 3: Cable glands
Type B
Standard design: IP 41
Option 1: Cable box with rating IP 55 (for higher ratings please contact us)
Option 2: Internal busbars for cable incoming from below
Option 3: Cable glands
Type C
Standard design: IP 41
Option 1: Cable box with rating IP 55 (for higher ratings please contact us)
Option 2: Not available
Option 3: Cable glands
Type D
Special design (upon request): IP 41
Option 1: Cable box with rating IP 55 (for higher ratings please contact us)
Option 2: Not available
Option 3: Cable glands