Acme Non-Linear K-Rated Transformers

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 Corporation was founded in 1917 in Cleveland, Ohio. Since that time, Acme has been a leader in supplying power conversion equipment to the electrical and electronic markets. Dry type distribution transformers have been a central part of the Acme product line for over sixty years.

Many of today's electronic devices are non-linear loads generating high levels of harmonic currents that are then fed back onto your distribution system. This results in overheating of motors and transformers, increased neutral currents and malfunction or damage to other equipment on the line.

Non-linear loads generate high levels of harmonic currents. When supplying power to these loads, a special transformer design is necessary. Typical non-linear loads include desktop computers, AC variable speed drives, HID lighting, electronic ballasts, inverters and welders. Of these non-linear loads, the major source of harmonic currents is the switch mode power supply found in desktop computers, data processors and other office equipment. Acme non-linear load isolation transformers use special winding techniques to minimize eddy current losses generated by harmonic currents. A double-sized neutral conductor handles the excessive neutral current found in non-linear load applications. The amount of harmonics produced by a given load is represented by the term “K” factor. The larger the “K” factor, the more harmonics are present. Linear loads have a “K” factor of 1; switch mode power supplies typically have a “K” factor as high as 20. Acme non-linear load isolation transformers are shielded for cleaner power and carry the Acme exclusive 10-year limited warranty.

FEATURES

• Available in K-factors of 4, 13 and 20. Consult factory for other K-factors.
• 150°C, 115°C and 80°C temperature rise units.
• 10-year limited warranty.
• UL Listed and CSA Certified.
• Available in 480V and 600V primary,15 through 600 KVA.
• Primary taps: (2) 2 1/2% ANFC, (4) 21/2% BNFC.
• Aluminum and copper windings

The following guide will help you select the proper
transformer when the K-factor is unknown.*

K-Factor/Type of Load

K-1: Resistance heating,  Incandescent lighting,  Motors Transformers control/distribution

K-4: Welders, Induction heaters, HID lighting, Fluorescent lighting, Solid state controls

K-13: Telecommunications equipment, Branch Circuits in classrooms and health care facilities

K-20: Main frame computers, Variable speed drives, Branch circuits with exclusive loads of Data Processing equipment, Desktop computers

* These ratings are to be used as a guide only. They may vary from one load equipment manufacturer to
another. A Spectrum Analysis is the best source.
Note: Non-sinusoidal and non-linear are synonymous
terms relating to the same transformer type.

Definition of Terms

1. Linear loads
Loads where the current waveform conforms to the waveform of the applied voltage. Or loads where a change in current is directly proportional to a change in applied voltage.

 For example:
• Resistance heating
• Incandescent lighting
• Water heater

2. Non-linear loads
Loads where the current waveform does not conform to the waveform of the applied voltage. Or loads where a change in current is not proportional to a change in applied voltage.
Examples are:
• Computer power supplies
• Motor drives
• Fluorescent lighting
Non-linear loads produce non-sinusoidal current or voltage waveforms.

3. Sinusoidal current or voltage
This term refers to a periodic waveform that can be expressed as the sine of a linear function of time.

4. Non-linear currents or voltages
A waveform of current or voltage which cannot be expressed as the sine of a linear function of time. A non-linear load would result in a non-sinusoidal current or voltage.

5.Harmonic
A sinusoidal waveform with a frequency that is an integral multiple of the fundamental 60 Hz frequency.
120 Hz 2nd Harmonic
180 Hz 3rd Harmonic
240 Hz 4th Harmonic
etc.
Current waveforms from non-linear loads appear distorted because the non-linear waveform is the result of adding
harmonic components to the fundamental current.

6.Triplen harmonics
Odd multiples of the 3rd harmonic (3rd, 9th, 15th, 21st, etc.).

7. Harmonic distortion
Non-linear distortion of a system characterized by the appearance in the output of harmonic currents (voltages) when the input is sinusoidal.

8.Voltage harmonic distortion (VHD)
Voltage harmonic distortion is distortion caused by harmonic currents flowing through the system impedance. The utility power system has relatively low system impedance, and the VHD is very low. But, VHD on the distribution power system can be significant due to its relatively high system impedance.

9.Total harmonic distortion (THD)
The square root of the sum of the squares of all harmonic currents present in the load excluding the 60 Hz fundamental. It is usually expressed as a percent of the fundamental.

10. Root mean squared current (or voltage) RMS
1: The vector sum of the fundamental current and the total harmonic distortion.
2: Square root of the sum of the squared value of the fundamental current and the squared value of the total
harmonic distortion.

11. Eddy currents
Currents flowing in a conducting material in the presence of a time varying magnetic field. These currents are in addition to the current drawn by the load.

12. Eddy current losses
Power dissipated due to eddy currents. Includes eddy current losses in the core, windings, case and associated hardware of a transformer.

13. Stray losses
A term used to express the difference between the measured alternating current losses on a transformer
and the direct current (DC) losses (I2R). Stray losses include eddy losses. Stray losses are usually expressed as a
percent of the direct current (DC) losses.

14. Per unit value
1: Percent value divided by 100.
2: The ratio of two components of a system.

15. Harmonic spectrum “K” factor
The sum of the product of each harmonic current squared and that harmonic number squared for all harmonics from the fundamental (60 Hz) to the highest harmonic of any measurable consequence. When the “K” factor is multiplied by the stray losses of the transformer, the answer represents the losses in the transformer caused by harmonic currents. When these losses are added to the I2R losses of the transformer, the total load losses are known. The “K” factor for a linear load without harmonics is one (1).

SELECTION CHARTS
THREE PHASE

GROUP A, K FACTOR 20, 150 DEGREES C RISE
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP B, K FACTOR 13, 150 DEGREES C RISE
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP C, K FACTOR 4, 150 DEGREES RISE
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP G, K FACTOR 20, 115 DEGREES RISE
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP H, K FACTOR 13, 115 DEGREES RISE
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP I, K FACTOR 4, 115 DEGREES RISE
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

*consult factory for wiring diagrams

GROUP K, K FACTOR 13, 80 DEGREES RISE
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP L, K FACTOR 4, 80 DEGREES RISE
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP M, K FACTOR 13, 150 DEGREES RISE
208 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP N, K FACTOR 20, 150 DEGREES RISE
COPPER NON-LINEAR
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP O, K FACTOR 13, 150 DEGREES RISE
COPPER NON-LINEAR
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP P, K FACTOR 4, 150 DEGREES RISE
COPPER NON-LINEAR
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP Q, K FACTOR 20, 115 DEGREES RISE
COPPER NON-LINEAR
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP R, K FACTOR 13, 115 DEGREES RISE
COPPER NON-LINEAR
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

GROUP S, K FACTOR 4, 115 DEGREES RISE
COPPER NON-LINEAR
480 DELTA PRIMARY VOLTS-208Y/120 SECONDARY VOLTS-30, 60 Hz

 Power Transformer Information:

 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 Transformers -  Federal 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 Transformers -  Hammond 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.

 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.