K-Factor Ratings of K-4, K-13 and K-20. Three Phase. 15-500 kVA for K-4, 15-300 kVA for K-13 and K-20.
K-Factor transformers are
designed to reduce the heating effects of harmonic currents created by
loads like those shown in the chart below. The K-Factor rating is an
index of the transformer's ability to withstand harmonic content while
operating within the temperature limits of its insulating system.
K-Factor transformers have UL ratings of K-4, K-13 and K-20.
These specialized transformers
feature conductors capable of carrying the harmonic currents of
non-linear loads without exceeding the temperature rating of the
insulation system. The basic design takes 
into account the increase in
naturally occurring “stray” losses caused by non-linear loads that can
cause standard transformers to dramatically overheat and fail
prematurely. The core and coil design manages the DC flux caused by
triplen harmonics that can cause core saturation, voltage instability
and overheating in a standard transformer.
K Factor Ventilated Transformer Catalog Pages
Features
- Conductors carry the harmonics of a K-rated load without exceeding insulation temperature ratings
- UL 1561 Listed up to K-20 rated protection
- Rated temperature rise of 150°C/302°F, 220°C/428°F insulation
- Shielded for quality power
- Basic design takes “stray losses” into account, functioning within safe operating temperatures
- Core and coil design is engineered to manage the zero sequence flux caused by triplen harmonics
- Provides 100% rated current without overheating the windings or saturating the core
- Accessories and Optional Design Styles
- Wall mounting brackets (item WB1C, 500 lbs. maximum)
- Weather shields (UL-3R, order separately)
- Totally enclosed, non-ventilated designs (TENV, non-UL)
- Open core and coil designs (UL Recognized)
- Low temperature rise units available
- Copper-wound designs
- Alternate voltages
- Compliant to NEMA TP-1 standards
Selection Steps
Overcurrent Protection
Fuse Recommendations
Three Phase Fuse Recommendations
