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Autotransformer

Product Overview & Application

autotransformers

Autotransformers are transformers which have a single winding per phase, part of which is common to both primary and secondary circuits. Using an Autotransformer is an economical and compact means of connecting electrical equipment to a power supply or a different voltage. Part of the winding is common to both primary and secondary circuits so there is no isolation between the two. This may be acceptable on some power systems that do not have a grounded neutral on the secondary side of the main power transformer. Typical applications include motor loads of industrial machinery, electric heating, air conditioners, etc. Designed for installation where a reliable power source is required for lighting and other low voltage equipment and machinery. Indoor and outdoor installation is possible depending on the enclosure.

Features & Benefits

  • Performs same function as an isolation transformer of same kVA and voltage rating without the isolation feature.
  • Generally radiates less noise than equivalent isolation transformer.
  • All terminals are clearly identified and easy to connect.
  • May be used in either step-up or step down configuration.
  • Low regulation; less than three percent.
  • Class 220 insulation used throughout range.
  • CSA certified, File No. LR 34493.
  • UL listed, File No. E108255.
  • General-purpose ventilated steel enclosure suitable for indoor location. After fabrication, all metal is finished in ASA 61 grey power coating suitable for most industrial and commercial installations.
  • Transformers in enclosures up to #7 may be readily hung on H-columns, walls, shelves or floor mounted to suit each installation. All units have lifting lugs, and removable top, front and rear panels for convenient access to the terminals.
  • Transformers in enclosure #8 or larger are suitable for floor or platform mounting and complete with integral lifting lugs, and removable top, front, and rear panels for convenient access to the terminals.

Product Specification

Capacity  3 to 333kVA Single Phase and 5 to 750kVA Three Phase
Voltage Class  1.2kV
Cooling  Self Cooled (ANN / AN)
Frequency  60Hz (50/60Hz Optional)
Conductors  Copper (Cu) or Aluminum (Al) Windings
Insulation System  220°C (150°C Rise) (Optional 115°C or 80°C Rise Available)
Impregnation  Polyseter Resin Dipped and Baked
Sound Level  Meets NEMA ST-20
Enclosure Type  Type 1 or 3R Indoor (Refer To Catalog)
Enclosure Finish  ANSI/ASA 61 Grey
Warranty  12 Months (See Warranty and Limitations)
Quality System  ISO 9001:2015 Quality Management System
Certifications
  • CSA Certified
  • UL Listed
Reference Standards
  • CSA C22.2 No 47
  • CSA C9
  • IEEE C57.12.01
  • IEEE C57.12.91
  • NEMA ST-20
Optional Features & Accessories
  • Suitable for 50Hz Nominal Frequency
  • 115°C or 80°C Temperature Rise
  • Neutral Brought Out To Terminal
  • Primary Voltage Taps
  • Thermal Sensing & Indication
  • Thermometers (Analog/Digital)
  • Thermostat Alarm / Trip (N.O. /N.C. contacts)
  • Electrostatic Shielding
  • K-Factor Rated To Handle Current Harmonics (K4, K9, K13, K20)
  • Anti-Condensation Strip Heaters
  • Surge Protection Devices
  • External Anti-Vibration Pads
  • Type 1, 2, 3R, 4, 4X or 12 Enclosures
  • 304 or 316L Stainless Steel Enclosure
  • Custom Enclosure Finish (Color)

Documentation

Drawings