Industrial Control Transformers
Category: TransformersIndustrial Control Transformers are intended for industrial applications where higher single-phase voltages need to be converted down to usable AC line voltages. Even before selecting an Industrial Control Transformer, various specifications must be kept in mind like load, minimum voltage required for operation, inrush load power factor etc.
Industrial Control Transformers are designed with very low temperature rise, exceptional voltage regulation and great overload capacity of high momentary in-rush current demand by the contactors, relays and solenoids. The voltage drop under high transitory in-rush current is also very low, which guarantees satisfactory operation of contactors, relays and solenoids.
Features of an Industrial Control Transformer
An Industrial Control Transformer is usually,
- Encapsulated in epoxy which seals the transformer coils against moisture, dust, dirt and industrial contaminants for maximum protection in hostile and industrial environments
- Fuse clips for most models. Factory mounted for integral fusing on the secondary side to save panel space, save wiring time and save the cost of buying an add-on fuse block or kit
- Integrally molded barriers between terminals and transformer protects against electrical creepage. Up to 30% greater terminal contact area permits low-loss connections. Extra-deep barriers reduce the chance of shorts from frayed leads or careless wiring
- Terminals molded into the transformer are difficult to break during wiring. A full quarter-inch of thread on the 10-32 terminal screws prevents stripping and pull out
- Two jumper links are standard with all transformers which can be jumped
Operation of an Industrial Control Transformer
Industrial control circuits and motor control loads typically require more current when they are initially energized than under normal operating conditions. This period of high current demand, referred to as an inrush, may be as great as ten times the current required under steady state or normal operating conditions, and can last up to 40 milliseconds. A transformer in a circuit subject to inrush will typically attempt to provide the load with the required current during the inrush period. However, it will be at the expense of the secondary voltage stability by allowing the voltage of the load to decrease as the current increases. This period of secondary voltage instability, resulting from increased current, can be of such magnitude that the transformer is unable to supply sufficient voltage to energize the load. The transformer must therefore be designed and constructed to accommodate the high inrush current, while maintaining secondary voltage stability. According to NEMA standards, the secondary voltage would typically be 85% of the rated voltage.
Selecting an Industrial Control Transformer
Should your organization be looking to invest in a industrial control circuit transformer, the following is what you need to understand:
Inrush VA – is the product load voltage (V) multiplied by the current (A) that is required during circuit start-up. It is calculated by adding the inrush VA requirements of all devices, which will be energized together.
Seated VA – is the product of load voltage (V) multiplied by the current (A) that is required to operate the circuit after initial start-up or under normal operating conditions. It is calculated by adding the sealed VA requirements of al electrical components of the circuit that will be energized at any given time.
Primary Voltage – is the voltage available from the electrical distribution system and its operational frequency, which is connected to the transformer supply voltage terminal.
Secondary Voltage – is the voltage required for load operation which is connected to the transformer load voltage terminals.
Primary Fuse Kit – this kit includes a 2-pole class CC fuse block, instructions and all associated mounting and wiring hardware.
Industrial control transformers from Pacific Crest Transformers
Pacific Crest Transformers builds industrial transformers specifically designed to meet client needs to provide feeder voltages to the single phase control transformers described in this article. We also offer Custom Design Transformers to meet the most demanding industrial situations without compromising on quality and performance levels. Custom designed transformers are manufactured keeping in mind specifications given by the clients and industry standards. Our transformers are built to handle the roughest industrial situations. |
