Spec Tech Industrial
Back to Dongan

Buy Your Industrial Control Products Here!


K-Factor Transformer for Harmonic Loads

Domestic distribution systems and linear loads operate at the fundamental frequency of 60 Hz. Harmonic content in distribution systems means that there are integer multipliers of the fundamental 60 Hz frequency present. For instance, the second harmonic is 120 Hz, the third harmonic is 180 Hz, the fourth harmonic is 240 Hz, etc.

Transformers operating in a distribution system containing significant harmonics will exhibit potentially serious effects of increased operating temperature. Additionally, it is common to find overloaded neutral conductors resulting from the additive effect of third harmonic and succeeding odd multiple harmonic current flow (triplen harmonics) as well as circulating currents in the primary, eddy current losses, and skin effect losses.

Harmonic content of a distribution system is indicated by a number called K-Factor. Larger values of "K" indicate the presence of more harmonics in the load. Harmonic content of a load may be determined by measurement utilizing a recording analyzing meter. Linear loads have a K-Factor of 1. Switch mode power supplies have a K-Factor as high as K-20. Other nonlinear loads have a K-Factor which varies with the device.

Dongan K-Factor transformers are specifically engineered to operate at full load and full harmonic rating without exceeding the rated insulation system values - effectively neutralizing the dangerous effects of temperature and circulating currents. Windings and cores are designed to operate in the presence of triplen harmonics without overheating or forcing the core into saturation. These transformers will provide years of trouble free service to large office buildings, industrial plants, processing equipment and any load with a designated harmonic content.

UL Recognized Insulation System File E100887.
Three Phase: 15 - 150 kVA
Electrostatic shield between windings provides cleaner output voltage and helps to reduce spikes and transients.

Aluminum windings connect to bus bar style terminations equipped with NEMA standard holes for compression style terminals.

UL Class 220°C insulation system with 150°C temperature rise at full load and rated ambient.

NEMA-3R, ventilated, cabinet style, floor mount enclosure suitable for indoor or outdoor use. No extra rainshields required for outdoor use.

Vibration dampening pads provide quiet operation.

K - Factor Transformer Voltage Combinations
K-4 480 X 208 Y / 120
K - 13 480 X 208 Y / 120
K - 20 480 X 208 Y / 120
203 Vest Avenue
Valley Park, MO 63088
Toll Free: (888) SPECTECH
Phone: (636) 537-0202
Fax: (636) 537-1405
E:mail: sales@spectechind.com