Block CT

Variant in Current Transformer: Block CT

A control transformer is a transformer that is used to step down the voltage to power the control devices of a circuit or machine. The reduced voltage provides a much safer environment for technicians working on the equipment. Residential heating, ventilating, air conditioning systems, and other machines use reduced voltage for the controls, thermostats, relays, and contactors.

Control transformers are often referred to as power supplies. Control transformers with two primary coils and one secondary coil are the most common. A control transformer's primary coils are crossed so that metal links can be used to connect the primaries for 240 V or 480 V operation.

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Features
Technical Specifications
Dimension
Test Report

Standard Features:

Designed for LT epoxy moulded metering class current transformer applications.
Suitable for three-phase four-wire energy measuring systems.
Can be installed for outdoor applications.
Supplied with all necessary parts and accessories for efficient operation.
Manufactured as per relevant Indian and IEC standards.
Undergoes stage testing, inspection, and pre-dispatch testing.
Built following good engineering and quality manufacturing practices.
Properly packed to ensure safe supply and delivery.
Dimensional tolerances maintained as per standard specifications.
Ensures accurate and reliable energy measurement performance.

Feature	Value
Type	3-Phase, Resin Cast Block CT
Standards	IS: 2705 (Part I-IV) / IEC 61869-2
System Voltage	3 kV (LT Application)
Ratio	60/5 A, 100/5 A, 150/5 A, 200/5 A
Core	Single core per phase
Accuracy Class	Class 1
Burden	5 VA
Window / Inner Diameter	25 mm
Frequency	50 Hz ± 5%
Continuous Thermal Current	1.2 × rated current
Short Time Current	As per IS: 2705 (e.g., 25 × rated current for 1 sec)
Instrument Security Factor (ISF)	≤ 5
Construction	Resin / Epoxy encapsulated, flame-retardant block housing
Terminals	Electrolytic copper, screw-type with protective cover
Mounting	Optional mounting clamp / Busbar / Cable pass-through
Insulation	Class E / Class B
Ambient Temperature	-10°C to +55°C
Service Conditions	Indoor, suitable for tropical climate
Markings	As per IS: 2705 (Ratio, VA, Class, Serial No., Year, IS marking)
Routine & Type Tests	As per IS: 2705 (Polarity, Ratio, Burden, Accuracy, Dielectric, etc.)