What is mean CT in electrical?

Answer 1

It could mean several things, depending on context:

• Center Tap, as in a transformer winding with a center tap
• Current Transformer, as used in kWHr meter to measure electricity use
• Contact Time, of a relay
• CounTer, an electrical/electronic counter
• Control Techniques
• Cellular Telephone
• Cycle Time, as in memory cycle time, etc.
• Charge Transfer
• Cross Talk, a type of signal interference
• Cable Tray, a tray used to suspend cables and wiring above a ceiling
• Cordless Telephone
• Crimp Tool, a device to crimp connectors on the ends of cables/wires
• Control Transformer
• Color Television
• Cable Television
• Clear Trunk, idle telephone trunkline
• etc.

Another Answer

The abbreviation, 'CT', is most-widely used to describe a current transformer. Together with the 'VT' ('voltage transformer') [known as a 'PT' or 'potential transformer' in North America], these Transformers are collectively-known as 'instrument transformers'.

A CT is most-commonly found in high-voltage substations where it is used to (a) step down the heavy transmission/distribution currents to values (typically around 5 A) that can be handled by an ammeter or protective relay, and (b) to isolate that ammeter or relay from the high-voltage system for reasons of safety.