What is a Control Transformer?

A control transformer is an isolation transformer designed to provide a high degree of secondary voltage stability (regulation during a brief period of overload condition (also referred to as “inrush current” ). Control transformers are also known as Machine Tool Transformers, Industrial Control Transformers or Control Power Transformers.
When you calculate the VA requirement of a Transformer, do you use the Primary or the Secondary Voltage?
When selecting the VA requirement, you use the Secondary Voltage.
Can you use a Control Transformer connected in reverse?
Yes, a control transformer can be connected in reverse. However, keep in mind the output voltage will be less than its rating, due to the compensation factor of the windings.
Can a Control Transformer regulate the output voltage?
A control transformer will not regulate the voltage. Output voltage is a function of the coil’s turn ratio only, times the input voltage.
What is the benefit of “Vacuum Impregnation” on a Transformer?
All HPS Control Transformers are vacuum impregnated with “VT Polyester Resin” and oven cured which seals the surface and
eliminates moisture. Impregnating the entire unit provides a strong mechanical bond and offers protection from environmental conditions.
Explain the “VA” or “Volt Ampere Output” Rating?
The VA or volt ampere output rating designates the output which a transformer can deliver for a specified time at its rated secondary voltage and rated frequency, without exceeding its specified temperature rise.
Insulating Materials; what are they made of and what is their purpose?
Hammond Power Solutions utilizes Mylar, Nomex and other high quality insulating materials. Insulation is used to electrically insulate turn-to-turn windings, layer-to-layer windings, primary to secondary windings and ground.
What is the effect of “Overload”?
When a transformer is continually overloaded, excessive heat develops and the insulation system will begin to breakdown. As a result, the life expectancy of the transformer is shortened due to the heat exceeding the rating of the insulation system.