MG-XX SERIES LIQUID FILLED SUBSTATION TRANSFORMERS

 Applications for Liquid-Filled Secondary Substation

Types of Transformers:

• • Multi-tapped
  • K-Factor Rated
  • Unit Substation
  • Auto Transformers
  • Scott-connected Transformer
  • Zig-Zag Grounding Transformer
  • Rectifier Duty (6, 12, 18 and 24 pulse)

Transformer Ratings:

• • Three Phase up to 34.5 kV
  • 112½ kVA to 10 MVA
  • 50 or 60 Hz

The highest-quality materials and manufacturing processes combined with skilled and flexible custom-engineered design enables L/C MAGNETICS Transformer Company to understand, design, manufacture and support to your exact specifications and requirements. We make certain that our world-renowned quality is exemplified by every product carrying our label.

L/C MAGNETICS’s three-phase liquid-filled secondary substation transformers are specifically designed to change distribution voltages to utilization voltages to meet any industrial or commercial application. All of our products are designed to meet or exceed applicable ANSI, NEMA and IEEE standards and can be supplied with many combinations of terminal arrangements. Our mission is to ensure operational excellence, be the leader in quality transformer product and attain the shortest cycle times in the industry.

Industrial

L/C MAGNETICS Transformer is known by its many industrial customers for providing reliable, custom-built transformers with faster turn-around times than any other manufacturer. Our transformers will meet and exceed both your and your customers’ expectations; whether needed for standard distribution loads or high-impact drives or process rectifiers.

Commercial

Contractors know they can depend on L/C MAGNETICS Transformer even when the job requires small footprints, low sound levels, non-standard documentation, matching dimensions or any other critical consideration. Reduced lead times are available as well through our “Bull Rush” program.

Harmonic Content

ANSI standards enable only 5% maximum harmonic content of load current for standard distribution transformers. If the distribution load consists of electronic power supplies, electronic ballasts and adjustable speed motor control, it would be prudent to investigate the harmonic content and, perhaps, specify a “K Rated” transformer. L/C MAGNETICS can help you determine required “K Factor” from the applicable harmonic current spectrum.

Other Typical Applications

• • Integrated Primary/Secondary Switchgear
  • Process I high-current rectification
  • Motor drive duty
  • Retrofit
  • Test

Liquid-Filled Features

Liquid-Filled Standard Features

• • Type I insulating mineral oil
  • 60 Hertz operation
  • 65°C average winding rise
  • Side-mounted bushings
  • HV /LV flange connections
  • Stainless steel nameplate
  • ANSI 61 paint finish, 5 mils thick
  • Pressure test valve
  • ANSI grounding pad
  • Pressure-vacuum gauge
  • Top filter press connections
  • Liquid level gauge
  • Liquid temperature gauge
  • Provisions for jacking and lifting
  • NEMA two-hole ground pads
  • Panel-type radiators as required.
  • Drain/filter valve with sampling device
  • Base suitable for rolling and skidding
  • Dial-type thermometer with maximum indicating hand
  • Externally operated de-energized tap changer providing (2) 2½% full-capacity taps above and below nominal

Optional Features Available

• • 55/65°C average winding rise
  • Forced air cooling
  • Future fan wiring and control
  • Removable radiators
  • Pressure relief device
  • Winding temperature indicator
  • Devices with alarm contacts
  • Top filter press valve
  • HV lightning arresters in ATC
  • Current transformers
  • Stress cones
  • Special impedances
  • Low loss
  • Special ambient
  • Special/low sound level
  • 50 Hertz
  • Retrofit to specific dimensions
  • Neutral grounding resistor
  • Rapid rise pressure relay, cover mounted
  • HV & LV air terminal compartments
  • Tertiary windings for Wye-Wye connections
  • 6, 12, 18 and 24 pulse drives applications
  • Non-standard loading conditions (i.e. Harmonics/K-factor)

Dielectric Coolant Choices for Liquid-Filled Units

Mineral Oil Filled:

The oil-filled unit is the least expensive transformer, and is suitable for mounting outdoors or indoors enclosed in a vault. The oil used in MGM transformers meets all the requirements of ANSI C57.106 and ASTM D-3487, has high dielectric strength, is free from impurities, is durable and has a high flash point These features make it an excellent insulating liquid.

Silicone Filled:

The silicone fluid selected for use in MGM transformers is a clear, liquid silicone polymer (polydimethyl-siloxane) that has been specially processed to meet exacting dielectric specifications. To obtain an optimum combination of heat transfer and fire-resistant properties, the transformer silicone fluid has a viscosity of 50 centistokes at 25°C. This fluid has a minimum fire point of 300°C and oxygen index of 21. The silicone fluid that we are using meets paragraph 450-23 (Less-Flammable LiquidInsulated Transformers) of the National Electrical Code. OSHA by its Program Directive 100-68 permits the use of silicone transformers as equivalent to askarel transformers in its enforcement of the National Electrical Code. Transformer silicone fluid has suitable dielectric characteristics, is compatible with other materials used in construction of transformers and has shown good thermal stability in accelerated aging tests with transformer materials.

Environmentally Friendly Dielectric Liquid FR3

A Fire-Resistant Hydrocarbon Fluid (FRHF) dielectric coolant formulated for use in distribution transformers is available when its unique electrical, thermal and safety properties are advantageous. It is non-toxic and readily biodegradable. It is also referred to as a High Fire Point Fluid, a High Molecular Weight Hydrocarbon or a LessFlammable Dielectric Liquid. The dielectric coolant is a listed less-flammable fluid meeting the requirements of National Electrical Code section 450-23, including a minimum fire point of 300°C and the requirements of the National Electrical Code (IEEE C2-1993). Section 15.

Tank Construction

MGM tanks are rugged, constructed from precision cut steel and braced to withstand the stresses of
shipping, rolling and jacking. They will withstand a pressure or vacuum of 7 psi without damage,
deterioration or leaking. All tank bases are designed to permit rolling in any direction perpendicular to
a tank wall. A bolted hand hole is provided in the cover, which is welded on. Leak tests are performed
before tanking and pressure tests prior to painting. Any combination of throat, flange or terminal chamber are available to match the requirement of a variety of high voltage switches and low voltage distribution sections. Custom design termination is also available for matching existing switch gear
in the case of PCB change-outs.

Quality Control — Test Procedures

All tests are performed in accordance with the latest revision of ANSI Standard Test Code for Transformers

• • Exciting current at rated voltage
  • Polarity and phase-relation tests on the rated voltage connection
  • Ratio tests on rated voltage connection and all tap connections
  • No-load loss at rated voltage
  • Resistance measurements of all windings
  • Insulation power factor test
  • Impedance and load loss
  • Applied potential tests
  • Induced potential test
  • Pressure leak test
  • Impulse tests