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Small kVA 3 Phase Transformers Guide



To Order Acme Transformers We Recommend TEMCo
Ph: 1-800-613-2290
Or 1-510-490-2187
Link: Acme Transformer


Acme Electric TransformersAcme Electric has manufacturer a full line of low voltage and dry type distribution transformers using both copper and aluminum conductor, offering an array of products between 0.250-1000 KVA. With Acme electric being in business over 80 years, they have always believe in offering there customers with superior service, quality and technical expertise in the transformer market. They supply transformers for industrial, commercial and OEM applications.

Acme Electric has over 170,000 square ft. of manufacturing facility with two plants. The main headquartered in Lumberton, North Caroline has 130,000 square ft. and  a 45,000 square ft. in Monterrey Mexico. The Lumberton, North Carolina facility serves as there headquarters and primary manufacturing location.

The Lumberton plant manufactures both air-cooled and encapsulated transformers. In 1997 Acme became certified in the Demand Flow Technology which allows them the ability to manufacture transformers in 2 to 3 days. The Monterrey Mexico plant manufactures smaller KVA and industrial control transformers. This modern facility serves as the central distribution center for the Mexican and Latin American marketplace.

Acme's product offers a full line of applications, from commercial general power distribution and high harmonic conditions to specific industrial motor drive/factory automation systems, to low voltage landscape lighting applications. All of Acme products are designed, constructed and rated in to meet or exceed the standards established UL, CSA CE, NEMA, ANSI and IEEE.

Acme electric also supply custom products to meet specific customer requirements. They offer an experienced design engineering department utilizing state of the art technology. With these technology, Acme provides rapid turnaround of designs and prototypes of custom products. Acme Electric has position it self to offer quality products match with superior customer service.

Acme Electric is a full line manufacturer of low voltage (600 V and below) dry type distribution transformers using both copper and aluminum conductor, offering an array of products between 0.250-1000 KVA.

Acme's product offering covers the full spectrum of applications, from commercial general power distribution and high harmonic conditions to specific industrial motor drive/factory automation systems, to low voltage landscape lighting applications. All Acme products are designed, constructed and rated to meet or exceed the standards established by UL, CSA, CE, NEMA, ANSI and IEEE.

Some of the Acme Products include:

Below are a few of Acme Transformers and there features:




Acme Dry-Type Distribution Transformers


  • Theaters

  • Hospitals
  • Education facilities
  • Office buildings
  • Industrial
  • Churches

Single Phase 37.5 to 250 KVA
Three Phase 25 to 1000 KVA


  • With weather shield, UL Type 3R enclosure type 2 enclosure without weather shield. UL listed and CSA certified.

  • UL Class 220 degrees C insulation system, 150 degrees C rise.

  • Extra large wiring compartment for easier installation and cooler case temperatures.

  • NEMA Standard bus bar terminals, no special tools needed to make clearly marked connections. Tap changing easily accomplished with jumpers.

  • Aluminum windings for increased insulation life, cooler operation, lower losses.

  • Noise and vibration isolating pads standard to assure quiet operation.

  • Large permanently legible nameplates on front.

  • Single phase units can be banked for 3 phase service.

  • All units have ground studs for use with non-metallic conduit.

  • Suitable for wall or "trapeze" mounting. Wall brackets are available for units up to 50 KVA Single and 75 KVA three phase.

  • Other models are available with class 220 degrees C insulation and either 115 degrees C or 80 degrees C rise operating temperature.

  • Termination-single phase 37.5 to 100 KVA, copper bus; 167 to 250 KVA, aluminum bus. Three phase 27 to 225 KVA, copper bus; 275 to 1000 KVA, aluminum bus.

  • Electrostatic shielding provided on all 60 Hz isolation transformers.

  • Electrostatic shielding not available on Groups DE and G1.





  • Theaters
  • Hospitals
  • Education facilities
  • Office buildings
  • Any application where transformers need to be installed in or near occupied areas
  • Churches
  • Libraries


  • 3 db below NEMA standard (LN3).
  • Encapsulated construction.
  • Three phase: 30-225 KVA, 480 Delta to 208Y/120
  • NEMA TP1 option available.
  • Aluminum windings standard.
  • Copper windings available.
  • NEMA 2 enclosures (3R with weather shield).
  • 220 Degrees C Insulation with 150 degrees C rise.
  • Electrostatic shielding.



Acme UL-3R Enclosure TransformersSingle Phase, .05 TO .150 KVA


  •  UL Listed, CSA certified and UL-3R enclosure meets or exceeds all listing criteria including NEMA, ANSI and OSHA standards.

  • Easy and convenient installation to meet your requirements, the transformer can be mounted in any position.

  • Long Life UL class 130 degrees C insulation system. Transformers cna be banked for three phase service.

  • Large wiring compartment, no conduit or pull boxes required. Front access for wiring ease. Wiring compartment remains cool.

  • Completely enclosed UL-3R enclosure for indoor/outdoor service. Rugged non-ventilated construction.

  • Plenty of knockouts for multi-directional entry.

  • All copper lead wire terminations.

  • Ground studs for use with non-metallic conduit.

Single Phase, .250 to 25 KVA


  • UL listed, CSA certified and UL-3R enclosures meets or exceeds all listing criteria including NEMA, ANSI and OSHA standards.
  • Shielded for cleaner power.
  • Encapsulated and completely enclosed design electrical grade silica and resin compounds completely enclose the core and coil to seal out all moisture and air. UL Type 3R enclosure for indoor or outdoor service. Encapsulation eliminates corrosion and insulation deterioration.
  • Quiet operation with sound levels well below NEMA standards.
  • Long life UL class 155 degrees C insulation system. 115 degrees rise thru .750 KVA: 180 degrees C insulation system, 115 degrees C rise, 1 KVA and above.


ACME Low Voltage Transformers


  • Landscaping

  • Indoor lighting


  • UL Listed, CSA Certified.

  • 100, 150, 300, 600, 750, 1000 VA.

  • 1 Phase, 60 Hz, 120 or 240 volt input.

  • 12 0r 24 volt output.

  • Input Auto-thermal reset switch.

  • Output circuit breaker

  • Fully encapsulated core and coil

  • Full fault current carrying Faraday Shield.

  • Flexible copper leadwire terminations.

  • UL class 180 degrees C insulation system 115 Degrees C. Rise.

  • UL Type 2 enclosure.

  • Keyhole slotted wall mounting brackets.

  • Black finish.

  • Bottom access.

  • Two 0.875 (2.2 cm) single knockouts each side.

  • Two dual 0.875 (2.2) and 1.125

  • (2.9 cm) knockouts on bottom cover


 Power Transformer Information:

Power Transformer HomeContact Power Transformer Co.

Power Transformer Types

Step Up and Step Down Transformers Step Up and Step Down Transformers to Power transformers to step-up ( raise) or step-down (lower) the electrical voltage.
Isolation Transformers Isolation Transformers allows signal or power to be taken from one device and fed into another without electrically connecting the two.
Toroidal Transformers Toroidal Transformers are devices that transfer electrical energy from one electric circuit to another, without changing the frequency, by electromagnetic induction.
Custom Transformers
Custom Transformers are designed to meet certain performance specifications and size requirement that you require. There is a wide range of custom transformer types.
Buck Boost Transformers
Buck Boost Transformers is a ideal solution for changing line voltage by small amounts. Often used to buck (lower), or boost (raise) the voltage from 208v to 240v for lighting applications.
Pole Mounted Transformers
Pole Mounted Transformers are mounted to poles for overhead electrical lines. Used in various applications. Are available in single phase or three phase transformers.
Medium Voltage Transformers
Medium Voltage Transformers are used with a medium range of voltages. They come in a full range from liquid-filled, convention dry type as well as cast coil.
Pad Mounted Transformers Pad Mounted Transformers are a excellent choice for commercial and industrial such as manufacturing facilities, refineries, office buildings, schools, hospitals, restaurants, and retail stores. They come in various sizes and can be used underground as well.
High Voltage Transformers High Voltage Transformers typically these voltage transformers are used in power transmission applications. High voltage transformers are also used in microwave.

 Power Transformer Manufacturer

  • ACME Transformers - With Acme Electric being in business over 80 years, they have always believed in offering there customers superior service, quality and technical expertise in the transformer market.
  • AMVECO Transformers - AMVECO designs and manufactures toroids transformers, current transformers, and auto transformers. Most AMVECO products are custom designed utilizing their state-of-art proprietary CAD programs.  The AMVECO engineers can quickly generate designs in a matter of hours, if needed.
  • Federal Pacific TransformersFederal Pacific is a division of Electro- Mechanical Corporation, a privately held, American owned company founded in 1958. Federal pacific offers dry-type transformers from .050 KVA through 10,000 KVA single and three phase, up to 34.5 KV, 150 KV BIL with UL approval through 15 KV.
  • Marcus Transformer - Ever since they opened their doors for business a half a century ago, they have been a leader in innovative transformer design. As a family-owned company they are proud of the reputation they have earned for making quality-built transformers that deliver exceptional performance and savings.
  • Hammond TransformersHammond Manufacturing was founded in 1917 in Guelph, Ontario, Canada. In the last 3 decades it has expanded to the US and the international markets offering many types of power transformers. 
  • TEMCo Transformers - TEMCo Transformer, a family-owned business which has been manufacturing and distributing electrical products since 1968. They focus on transformers that significantly reduce power consumption over 30 percent compared to competitive makes.
  • GE Transformers - GE has been a key player in the energy industry for more than a century.  Since the installation of their first steam turbine in 1901. They have become number one provider of high-technology power generation and distribution equipment.
  • Jefferson Electric Transformers - Jefferson Electric has been a pioneer and innovator of magnetic products since 1915. Jefferson broad line of dry-type transformers are backed by quality assurance systems so stringent that each and every unit gets thoroughly tested before it goes out there door.
  • More power transformer brands - Check out more companies by clinking this link.

 Power Transformer Types

  • Distribution Transformers - Distribution transformers are generally used in electrical power distribution and transmission power. This class of transformer has the highest power, or volt-ampere ratings. and the highest continuous  voltage rating.
  • Substation Transformers - Substation Transformers are large devices which usually weigh tens of thousands of pounds.   They are filled with tens of thousands of gallons of heat transfer fluid.  Although they are typically 99.8% efficient in the transforming of electricity from one voltage to another, processing hundreds of Mega Volts-Amps of electricity force the liberation of hundreds of BTUs per second.
  • Medical Grade Isolation
     Transformer -
    Medical Grade Transformers generally refer to the transformers used in medical devices as well as hospital, biomedical and patient care equipment. There are a number of strict safety rules, guidelines and laws governing the design, construction and the test of these transformers.
  • Drive Isolation Transformer - They are used to isolate a drive from a main power line to prevent the transmission of harmonics that the drives produce back into the power line.  They stop drive harmonics from disrupting computers and other sensitive equipment.
  • Toroidal Transformers - Toroidal Transformers are more efficient than the cheaper laminated EI types of similar power level. Some of the advantages are smaller size, lower weight, less mechanical hum, (making them superior in audio amplifier), low-off-load loss.
Capacitor for Motor Resources






  Power Transformer Types

  • Step-Up Transformers - A Step-Up Transformer is one whose secondary voltage is greater than its primary voltage.  This kind of transformer "steps up" the voltage applied to it. -
  • Step-Down Transformers - A Step-Down Transformer is  designed to reduce voltage from primary to secondary.  They can range from sizes from .05 KVA to 500 KVA
  • Isolation Transformers - An Isolation Transformer is a device that transfers energy from the alternating current (AC) supply to an electrical or electronic load.  It isolates the windings to prevent transmitting certain types of harmonics.
  • Buck Boost Transformers - Buck Boost Transformers make small adjustments to the incoming voltage. They are often used to change voltage from 208v to 240v for lighting applications.  Major advantages of Buck boost transformers include; low cost, compact size and light weight. 
  • High Voltage Transformer - There are many different types of voltage transformers. A High Voltage Transformer operates with high voltages. Typically, these voltage transformers are used in power transmission applications, where voltages are high enough to present a safety hazard.
  • Medium Voltage Transformers - A Medium Voltage Transformer can be connected directly to a primary distribution circuit and generally has the most load diversity. These voltage transformers have installation practices that are generally in accordance with application recommendations from the Institute of Electrical and Electronic Engineers (IEEE).
  • Low Voltage Transformers - A Low Voltage Transformer is an electrical device that transforms 120 volts (line voltage) into 12 volts or 24 volts (low voltage). Some uses for low voltage transformer are in landscaping lighting.
  • Single Phase Transformers - In electrical engineering, single-phase electric power refers to the distribution of electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors.
  • Three Phase Transformers - Three Phase Transformers must have 3 coils or windings connected in the proper sequence in order to match the incoming power and therefore transform the power company voltage to the level of voltage needed while maintaining the proper phasing or polarity.
  • Custom Transformers - Custom Transformers are designed for a certain performance specifications and size requirements.  The company works with your engineering specification. 
  • Industrial Control Transformers - Industrial Control Transformers are used to convert the available supply voltage to the required voltage to supply industrial control circuits and motor control loads.
  • Pad Mounted Transformers - Pad Mounted Transformers are usually single phase, or three phase, and used where safety is a main concern. Typical applications; restaurant, commercial building, shopping mall, institutional. 
  • Pole Mounted Transformers - Pole Mounted Transformers are used for distribution in areas with overhead primary lines. Outside a typical house one can see one of these devices mounted on the top of an electrical pole.
  • Oil Filled Transformers - Oil Filled Transformers are transformers that use insulating oil as insulating materials.  The oil helps cool the transformer. Because it also provides part of the electrical insulation between internal live parts, transformer oil must remain stable at high temperatures over an extended period.
  • Dry Type Transformers - Dry-Type Transformers are available for voltages up through 34.5 kV (although the most common upper limit is 15) and KVA ratings up through 10,000 (with 5000 as the usual limit). Dry-type use air as a coolant, lowering health and environmentally concerns.
  • Auto Transformers - An Autotransformer is an electrical transformer with only one winding. The winding has at least three electrical connection points called taps. Autotransformers are frequently used in power applications to interconnect systems operating at different voltage classes, for example 138 kV to 66 kV for transmission. Another application is in industry to adapt machinery built for 480 V supplies to operate on the local 600 V supply.
  • More power transformer types - Read further about additional transformer types and their uses.











  Power Transformer Term Definitions

  • Electrical Transformers - Electrical Transformers are devices used to raise or lower the voltage of alternating current. For instance, power is transported over long distance in high voltage power lines and then transformers lower the voltage so that the power can be used by a business or household.
  • Isolating Transformers - An Isolating Transformer is a transformer, often with symmetrical windings, which is used to decouple two circuits.  An Isolation transformer allows an AC signal or power to be taken from one device and fed into another without electrically connecting the two circuits. Isolation transformers block transmission of DC signals from one circuit to the other, but allow AC signals to pass. 
  • Transmission Power Lines - A Transmission Line is the material medium or structure that forms all or part of a path from one place to another for directing the transmission of energy, such as electromagnetic or acoustic waves as well as electric power transmission. Components of transmission lines include wires, coaxial cables,  dielectric slabs, option fibers, electric power lines, and waveguides.
  • Transformer Voltage - The measure of the amount of force on a unit charge because of the surrounding charge.
  • Transformer Phase - Most transformer are either single phase or three phase.
  • Transformer Frequency - The transformer cannot change the frequency of the supply. If the supply is 60 hertz, the output will also be 60 hertz.
  • Transformer K Factor - Some transformers are now being offered with a k-factor rating. This measure the transformer's ability to withstand the heating effects of non-sinusoidal harmonic currents produced by much of today's electronic equipment and certain electrical equipment.
  • Primary Voltage - The coil winding that is directly connected to the input power.
  • Secondary Voltage - The coil winding  supplying the output voltage.
  • Harmonic Cancellation - Harmonic cancellation is performed with harmonic canceling transformers also known as phase-shifting transformers. A harmonic canceling transformer is a relatively new power quality product for mitigating harmonic problems in electrical distribution systems. This type of transformer has patented built-in electromagnetic technology designed to remove high neutral current and the most harmful harmonics from the 3rd through 21st.
  • Weatherproof - Enclosed transformers come with a weatherproof standard set by NEMA.
  • Epoxy Encapsulated - A process in which a transformer or one of its components is completely sealed with epoxy or a similar material. This process is normally preferred when a unit might encounter harsh environmental conditions.
  • More power transformer terms - Such as inductor, ground fault, core saturation, current transformer, faraday shield, etc.

Related Transformer Products

  • Voltage Regulators - A Voltage Regulator is an electrical regulator designed to automatically maintain a constant voltage level.  It may use an electromechanical mechanism, or passive or active electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.
  • AC Line Reactor - AC Line Reactors is a three phase transformer used in conjunction with AC variable frequency and DC motor drive. They are a bi-directional protective filtering device.
  • Line Power Conditioners - Power or Line Conditioners regulate, filter, and suppress noise in AC power for sensitive computer and other solid state equipment.
  • DC Power Supplies - Conversion of one form of electrical power to another desired form and voltage. This typically involves converting 120 or 240 volt AC supplied by a utility company to a well-regulated lower voltage DC for electronic devices.
  • Rotary Phase Converters - Rotary Phase Converters are commonly used in home or small commercial or industrial settings. Rotary phase converters convert single-phase power into three-phase power. This is a very cost-effective way to power three-phase electric motors and other three phase equipment.
  • Frequency Converters - A Frequency Changer or Frequency Converter is an electronic device that converts alternating current (AC) of one frequency to alternating current of another frequency.
  • Voltage Converters - A Voltage Converter changes the voltage of an electrical power source and is usually combined with other components to create a power supply.
  • Magnetic Motor Starters - Magnetic Motor Starters are essentially heavy duty relays mounted in boxes, often equipped with heater/thermal overloads matched to the motor they start.
  • Motor Starting Auto Transformers - An Auto Transformer starter uses an auto transformer to reduce the voltage applied to a motor during start. The auto transformer may have a number of output taps and be set-up to provide a single stage starter, or a multistage starter.

For an additional resource the Best of Industry Web Directory : Electrical Power Transformer Directory section is quite useful.