HPS cores are manufactured from the highest quality non-aging, cold rolled, silicon steel laminations. Cores are precision cut to close tolerances to eliminate burrs and interleaved to improve performance. Full mitre stepped core construction is used for our very high efficiency transformers.
Coils are available in either aluminum or copper construction. Coils are precision wound with continuous copper or aluminum conductors and are electrically balanced to minimize axial short-circuit forces. The use of duct stick permits the flow of air, thus providing excellent cooling in addition to providing superior radial mechanical strength.
The insulation rating is the maximum allowable winding (hot spot) temperature of a transformer operating at an ambient temperature of 40°C. Insulation systems are classified by the temperature rating. HPS energy efficient distribution transformers utilize superior insulation materials which meet or exceed UL standards. Higher ambient temperatures and/or continuous overload characteristics can be achieved with low temperature rise design.
HPS transformers are provided (where applicable) with both high and low voltage terminal lug connectors suitable for both copper and aluminum cables. These connectors allow for easy field installation without the need to purchase connectors separately, saving the installer both time and money.
Vacuum Pressure Impregnation (VPI) Regardless of voltage class, our polyester resin impregnation system is preferred. This material is a blend of a vinyl-toluene polyester resin and exhibits much higher dielectric strength and bonding properties than most varnishes previously used, or other encapsulations including oil modified epoxies. The VPI process ensures that the insulating resin penetrates all voids completely, and provides a superior result compared to simple dip and bake operations.
HPS has testing facilities in all manufacturing locations to ensure product quality. These testing capabilities include: Heat Run, Ratio, Polarity, Partial Discharge, Induced Voltage Test, Sound Level, Transformer Losses under linear and nonlinear load conditions, Applied Power Frequency Voltage Test, EMF, BIL, Insulation Resistance, Inductance and Resistance. HPS has a state-of-the-art test bench that can test transformer efficiencies with non-linear load profile up to K-Factor 20.