Dry VPI Distribution Substation

Overview

Dry VPI Distribution Substation transformers have voltage ratings of 600 V to 34.5kV and power ratings of 500kVA to 10,000kVA. Windings are Aluminum or Copper Windings and supported frequencies are 50/60/400 Hz; the insulation system is 220 °C and coils are Vacuum Pressure Impregnated. Standard features include DOE 2016 Efficiency Compliant, UL/CUL/CE/CSA listings, and conformance to IEEE C57.12.01, and units are Seismically Certified per ASCE/SEI 7-05 OSHPD OSP Pre Approval. Temperature Rise options listed are 150°, 115° or 80 °C Temperature Rise. Coils are vacuum pressure impregnated with solventless polyester resin for complete impregnation, and finished VPI coils are described as strong, readily dissipate heat and protected against moisture, dirt, and most industrial contaminants. Cores are constructed of non-aging, high grade, grain oriented silicon steel laminations with mitered construction and core clamping brackets that provide even distribution of clamping forces. The standard enclosure is NEMA 1, Category C construction with provisions for lifting, jacking, rolling or skidding, HV and LV ANSI ground pads, and a corrosion-resistant paint finish (ANSI 61 light gray); NEMA 3R outdoor enclosures are available. All units rated 750 kVA and higher can have added thermostatically controlled fans with control wiring, a thermal sensor and a fan controller to provide a forced air-cooled rating of 33% above the self-cooled rating. Each transformer receives standard production tests in accordance with IEEE C57.12.91: Resistance test; Polarity & phase relation test; Turns ratio test; No-load loss & exiting current test; Impedance and load-loss test; Applied potential test; Induced potential test. Dry substation transformers are explicitly described as being used in commercial buildings, industrial complexes, hospitals, data centers, airports, and indoor electrical substations. They are presented as suitable for indoor or environmentally sensitive installations, facilities with strict environmental standards, and areas where liquid-filled transformers are not permitted.