Articles

ENCLOSED TRANSFORMER

 

Enclosed transformers or known as totally enclosed non-ventilated (TENV) transformers are fundamentally different and the most desirable choice for applications where standard enclosure openings are undesirable because of adverse atmospheric conditions.
These transformers are designed for indoor or protected outdoor applications where dust, dirt or lint is present with contaminants in the ambient air and moisture. They are also recommended in the industries where they are subject to sprays or controlled wash-down conditions.
Enclosed transformers ensure sufficient heat absolution which is a critical factor where the heat passes from the core and coil to the internal air and then from the internal air to the outside atmosphere through the walls of the enclosure.
To avert excessive heating of the core and coil, these transformers are structured to perceive low temperature rise as there is no ventilation for enclosures and the internal temperature is higher than normal. The enclosures are comprehensive to be larger than the standard ones to protect the system with additional cooling and ensure sufficient surface area for to arrest the heat exchange.
The enclosed transformers are outfitted with re-connectable windings, non-standard impedance, terminal throats and chambers, shock indicator, customer-specific controls and relays, fan rating for 33% additional kVA ,winding temperature monitor, VPI + epoxy end cap, self-cooling or automatic fan cooling options, arresters and tamper-resistant hardware, air terminal chambers and flexible connectors to external bus, SCADA interface, provisions for parallel operation, voltage signal, loss evaluated design, seismic zone application, vibration isolation for hospitals and laboratories and disk windings up to 200 kV BIL.
The enclosed transformers are principally used in industries having chemical and cement plants, textile and paper mills, foundry and surroundings with contaminants such as gases laden with chlorine and sulfur, solids such as coal and metal dust, textile fibers, fumes and vapors.