Schneider Electric 9070 manual Technical Data

Industrial Control Transformers

Application

Technical Data

50/60 Hertz

Transformers that are dual rated for 50/60 Hz are truly global units and no derating is required for voltages or VA. (Type T are 50/60 Hz; Type EO are 60 Hz with de-rating for 50 Hz).

Base Plates

The development of welded cores has allowed the incorporation of base plates on larger VA transformers. Base plates are usually welded to the core of the transformer for a solid connection to the transformer. They allow manufacturers to offer more standardized mounting for specific VA sizes by allowing multiple core stacks. Available for Type T transformers only.

Touch-Safe Terminals

Being able to offer touch-safe terminals is increasing in importance. Currently all equipment that must comply with EN 60-204 (Machine and Low Voltage Directives) must have some type of barrier for live parts. Besides the CE standard listed above, domestic customers are requiring barriers on live parts with voltages above 460 V. These customers allow Plexiglas™ covers to be installed for these barriers.

Type T transformers can be made Fingersafe® by using snap-on covers that are removable with a screwdriver or other flat tool. Covers are sold separately.

Formed Terminal Board

Formed terminal boards are used on multiple VA ranges and different voltage combinations. This allows the manufacturer to punch jumpers for customer interconnections and gives the customer the same basic layout for all units. The snap-on covers for touch-safe terminations also are available on units with formed terminal boards. Available for Type T transformers only.

Varnish Vacuum Impregnation

This is a manufacturing process for the core and coil of industrial control transformers. The transformer is put into a tank of varnish, then the varnish is put into a vacuum, causing the varnish to be forced throughout the coil and core. After being vacuum impregnated, the units are cured in an oven to seal the varnish. The varnish is absorbed by any paper insulation system and coats other insulation with another layer of electrical strength. The process causes the coil to have a very tight connection because it is completely bonded and mechanically very strong. The cores are also tightly bonded with the varnish, causing the units to have better heat transfer and less vibration noise.

Schneider Electric uses this process on all control transformers, using a clear varnish with optimum electrical characteristics.

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