TMC TRANSFORMERS

The technical department of TMC provides the best solutions, both standard and customized, with the maximum guarantee of reliability found on the market today thanks to their expertise and the state-of-the-art technology available in the company.It is extremely important that a standard product be tested and verified in its first stages of design and that it is maintained under control during the production phases which are automated, for the most part. This is done not only for the sake of economies of scale but also to avoid human error that can happen during manual execution.

Below, briefly described, are the various classes and relative characteristics required of a product for certification.
All TMC products conform to E2, C2 and F1 classifications.

E0	E1		E2
No condensation, negligible pollution	Occasional condensation and moderate pollution		Consistent condensation and high-level pollution

E0 class requires no testing.
For class E1, the transformer is placed in a room with humidity at 93 % in presence of condensation. The equipment must stay in the room for at least six hours, after which an induced voltage test with value 1.1 Un for 15 minutes follows.
For class E2 the test is conducted in an analogous way but with an increase in conductibility and lasting 144 hours and is followed by induced voltage and applied voltage tests.

C1		C2
Functioning at minimum temperature of -5°C and storage up to -25°C.		Functioning, transport and storage up to the minimum temperature of -25°C.

For C1 class a thermal shock test is envisaged, during which the transformer is brought to an area and maintained at a temperature of - 5°C for a period of no less than 2 hours. Then current is applied equal to twice the nominal value in order to accelerate the heating of the conductor material. Following this verification takes place for the absence of any cracking phenoma of the insulation after which dielectric testing is performed.
Class C2 testing has an analogous procedure but varying the temperature to -25°C for 8 hours.

F0		F1
Risk of fire is not considered and no precautions are taken to limit the inflammibility.		The transformer is considered for risk of fire and a reduced level of inflammability is required. All related phenomena are subject to verification.

Class F0, analogous to class C0, requires no testing.
Testing is performed for class F1 on samples of material in order to verify the absence of toxic substances in percentages above the level envisaged by the standards. A combustion test is performed on the MV and LV coils assembled on a ficticious core column held together by a metalic cross bar. The combustion is obtained from burning alcohol and a radiant panel. Verifications and controls are made on the basis of pre established parameters of the extinction times of the fire, of the temperatures reached in the course of the combustion and of the opacity of the smokes.