Many control transformers are designed to provide 12V or 24V power from the secondary. However, some control transformers provide 120V power. For example, a control transformer with a 10:1 turns ratio can have the two primary coils wired in parallel.
Control transformers are available in a variety of primary and secondary voltage combinations from 120/240 primary voltage, 24 secondary voltage at 50/60Hz through 480 primary voltage, 240 secondary voltage at 50/60Hz up to 5000 VA rating. Typical Control Transformer applications may include: Hospitals. Office
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.
Transformers are rated in units called Volt-Amperes (VA). The NEC requires that for an output voltage higher than 50 VAC one side of a control transformer secondary be connected to ground or both sides of the secondary must be fused.
The term AC to DC transformer refers to a transformer that is connected to an AC rectification circuit. After increasing or decreasing the AC voltage, the rectification circuit converts the AC voltage to DC voltage. An AC to DC transformer is a simple solution for powering up electronics from the AC mains.
For proper control transformer specification, three characteristics of the load circuit must be determined in addition to the minimum voltage required to operate the circuit. These are total steady-state (sealed) VA, total inrush VA, and inrush load power factor.
A current transformer is designed to maintain an accurate ratio between the currents in its primary and secondary circuits over a defined range. The alternating current in the primary produces an alternating magnetic field in the core, which then induces an alternating current in the secondary.
The CVT (ferro) uses the unique principle of ferroresonance: operation of a transformer in the region of magnetic saturation. In the saturation region of the curve (red), a large change in input voltage results in a small change in output voltage.
Current transformers are used for protection, measurement and control in high-voltage electrical substations and the electrical grid. Current transformers may be installed inside switchgear or in apparatus bushings, but very often free-standing outdoor current transformers are used.
A current transformer is a device used to produce an alternating current in its secondary, which is proportional to the AC current in its primary. This is primarily used when a current or voltage is too high to measure directly.
Do you need to ground a motor?
Electrical motor windings are normally insulated from all mechanical parts of the motor. However, if the insulation system should fail, then the motor frame could become energized at line voltage. Grounding the motor frame prevents this possibility.