It is built with thin grain-oriented silicon steel, cold-rolled, with high magnetic permeability, M0H-M3 quality, manufactured at low flow densities to provide low losses and a minimum excitation current.
Copper and/or aluminum sole plate sheet with a double insulating varnish, Kapton double fiberglass liner or electrostatic dust.
Each transformer is submitted to routine tests for assuring the compliance with the client requirements. A test report is delivered as well.
· Turns ratio and connections polarity.
· Core losses and excitation current under vacuum.
· Conductor losses (copper and/or aluminum) and impedance percentage calculation.
· Applied voltage to high voltage winding for 1 minute.
Insulations up to 220ºC class are placed between windings and layers. Depending on their type of insulation, these materials do not absorb humidity, do not spread flames and they permanently guarantee an insulation resistance between the windings and the core.
Windings temperature increase.
Impregnation of the assembled transformer with core and coils, in a 24-hour varnish bath, ensuring a silent operation; it improves the insulation among turns and layers and protects the magnetic core from humidity.
"Kulka" or "Clema" terminal blocks strips, brass screws or copper sole-plate depending on the capacity, placed on celaron or epoxy blocks and on the upper part of the transformer.
They can be supplied with cabinets type NEMA 1 interior service, NEMA 3 rain proof or NEMA12 metal sheet dust proof.
Insulation resistance with megohmmeter. Total guarantee.
IMEM provides a guarantee for dry-type transformers against manufacturing defects and materials for one year following the shipment date.
Dry-type transformers are insulated with "B", "H" and/or "F" class materials, and are prepared for works in closed environments. Due to their safe operation, especially in case of fire, they have compact designs and are free of maintenance. Compared to other alternatives, their advantage is the low percentage of insulating materials as the steel toxic gases emission decreases (CO mainly) and premier finishing and ANSI61 gray color acrylic painting, or without a cabinet if prefered.
The transformer is fixed with a data plate carved in a visible part, in plastic paper for the interior service and of STAINLESS STEEL carved for weather service, with a clear identification of terminals, windings, frequency, voltage and maximum kva that will allow a safe connection.