What is temperature rise?
Temperature rise is the difference between the average temperature of the transformer windings and the ambient temperature.
What is hot spot?
The hot spot is an allowance selected to approximate the difference between the highest temperature inside the transformer
coil and the average temperature of the transformer coil.
Is one insulation system better than another?
One insulation system is not necessarily better than another. Each will typically provide a comparable life expectancy. The
choice of an insulation system depends upon application, performance and cost considerations.
Why is a control transformer needed?
A control transformer is required to supply voltage to a load which requires significantly more current when initially
energized than under normal steady state operating conditions. A control transformer is designed to provide secondary voltage
stability under a short period of specific overload referred to as inrush.
Are control transformers current limiting?
A control transformer is not current limiting and will allow as much current to pass through as is demanded by the load.
As such, a secondary overcurrent device should be utilized.
Will a control transformer regulate output voltage?
Control transformers are not voltage regulating. Because voltage changes are a function of the transformer's turns ratio,
variations in input voltage will be proportionally reflected to the output.
What is duty cycle?
Duty cycle is the period and duration when a transformer will be loaded. The transformer is designed to run continuously at full
load without exceeding the temperature limits. Transformers may also be operated for short time duty. Depending upon the time and
cycle of the maximum load, the transformer VA size may be smaller than for continuous duty.
What is the value of encapsulation in control transformers?
Encapsulating the coils of a control transformer will help to protect the unit from moisture, dust, dirt and industrial contaminants.
Encapsulation helps provide maximum protection in hostile environments while allowing the unit to run cooler than a
What effect does a control transformer have on electrical disturbances found on the line?
Because a control transformer has isolated primary and secondary windings, it will provide some degree of "clean-up" with regard to
electrical noise, spikes, surges and transients. It will not, however, provide the same degree of power conditioning found in
products designed for that purpose.