- The technical demonstration ce a transformer may be root by examining its spectry platter.
All transformers on the division and transmission nettoil enjoy a spectry platter. This platter has beneficial advice environing the transformer, e.g. – how it is cooled, its KVA rating, the year it was infuriated and its LV – HV preparation. The advice is stamped or expectationhed on so it is burning. 
Image 1 SSE GMT Dorset
- KVA – This is the transformers plain restraintce rating.
- Volts – This is the Leading and Promoteary voltages values of the transformer
- Amperes – This is the Max present rating ce the transformer
- Phases – The equality of edges on the HV and LV edges
- Diagram DWG No – Transformer schematic relation reckon
- Makers Serial No – This is the serial reckon from the transformers molding
- Polyedge KVA –
- Character of composure – The order the transformer is cooled
- Frequency – Reckon of cycles per promote in an alternating present
- Impedance – A affinity of the transformers regular generous attack present to the present conducive below incomprehensive circumference conditions
- Vector assemblage ref – indicates the windings configurations and the dissimilitude in edge disposition betwixt them
- Heart and windings – This is the burden of the heart and windings
- Burden of grease – This is the grease burden
- Total burden – this is the collectively burden of the grease, heart and windings
- Grease – This is the equality of grease in the transformer
- Year of molding – This is the year the transformer was infuriatede
- Owners No – This is where the possessor of the transformer can write there asset
With electrical machines it is very frequently the atmosphere loosen easy in the windings and insulation that determines the output, this applies distinctly to transformers.
Transformers are identified according to the composure balance employed and its prevalence order. The denominated learning are assigned.
Synthetic Insulating Liquid
The identification legislation used consists of 4 learning giving details of the composure balance and prevalence order ce twain leading and promoteary composure method.
1st missive – Order
2nd missive – Prevalence
3rd missive – Balance
4th missive – Prevalence
Composure balance in touch with winding
Composure balance in touch with superficial composure method
2. The restraintthcoming items are associated with restraintce transformers.
The grease warder is a uncompounded protecting artifice infuriatede of fencing steel, strong or referable to vacuum. It is
cylindrical and has brace fixing brackets. Usually, it is placed on a constituency agricultural on the transformer,
above the secure roll. In each edge of the warder there is individual recess allowing its cosmical washing during the exploitation. This recess is closed by resources of a platter, which can restrain (depending on the needs) an grease roll magnetic indicator.
The warder has sundry recesss to which are alike the identical piping. Each individual of
these piping has its local distillation (intercourse to the vital-force breather, to the transformer secure,
sampling, expectation.). If the transformer is equipped with on-attack tap changer, the warder is disconjoined by a septum. The larger allotment feeds the tank of the transformer and the smaller individual feeds the on-attack tap changer-breaking room. 
Every character of error which befalls in grease filed transformer gives loosen to the breed of fume which may be dull in the befallrence of less errors or furious in the befallrence of superior errors. The Buchholz reinforcement is inserted in the pipe intercourse betwixt the transformer tank and warder. The Buchholz reinforcement comprises of a mould strong housing which contains 2 elements. A mercury transport switch which discovers a gravitate in grease roll and a collectively deflector platter and transport switch mounted so that it conciliate discover any accelerated change-of-place of grease from the transformer to the warder.
The dull restraintmation of fume ascribable to a less error causes a tide of bubbles to by into the Buchholz room, resulting in a dull misplacement of the grease and threatening the excellent transport which when enough conciliate beget a “Buchholz Alarm”.
A grave error conciliate equality an explosive breed of fume which acceleratedly displaces the grease and causes a surge to by parallel the pipe towards the warder and in doing so displaces the falcation platter, unobstructed the inferior switch which equalitys a “Buchholz Taunt” which causes the transformer circumference breaker to taunt.
A leakage of grease from the transformer tank causes a unintermittent gravitate in the roll of grease which when enough conciliate be seen by the “Buchholz Alarm” transport switch.
The reinforcement is also disposed with a petcock which can be used to grasp grease samples ce partition of the error.
Image 3, SSE S/S Paisley Road, Southbourne, Buchholz reinforcement
Impartial Earsubject Resistor (NER)
Impartial earsubject resistors are a character of refuge artifice, protecting equipment when there is a error on the network. They toil by restricting the equality of voltage and present that flows through the impartial object of the transformer its alike to, to a roll that is sure preventing any detriment. Impartial earsubject resistors are generally alike betwixt reason and impartial of the transformer. 
Image 4, SSE S/S Paisley Road, Southbourne, NRE
Image 5, NER Diagram – 
3. Circulating presents can sometimes befall in a restraintce transformer, clear-up why this happens and whether it is a amiable subject ce restraintce transmission and division networks.
 Table from SSE Document Library Ref: TG-PS-445 33kV transformers