Custom Current Transformers (CT)

We supply a comprehensive range of custom built current transformers (CTs) designed for metering, protection, and specialised monitoring applications. Our CTs are engineered for high accuracy, reliability, and durability, making them suitable for switchboards, substations, industrial facilities, utilities, and power monitoring systems.

Available constructions include solid core, split core, tape wound, busbar type, and resin cast designs, allowing flexible installation across a wide range of electrical systems.

Metering Current Transformers (Metering CT)

Metering CTs are designed to accurately measure primary current in electrical feeders and provide a proportional 1A or 5A secondary output to power meters, energy management systems, and power quality analysers.

These CTs ensure precise current measurement for energy monitoring, billing, and system performance analysis.

Metering CTs are available in split core or solid core designs depending on installation requirements.

Available types include:

1. PVC tape insulated CTs
2. Busbar type CTs
3. Resin cast CTs
4. Ring type CTs
5. Custom built CTs for specific applications

Summation Current Transformers (Summation CT)

Summation CTs are used when multiple feeder currents need to be combined and measured by a single meter or monitoring device.

These CTs contain two or more primary windings, each connected to different feeders. The internal design sums the currents and delivers a single secondary output proportional to the combined current.

Example ratio

5 + 5 + 5 / 5A

This indicates that three 5A primary inputs are summed to produce a single 5A secondary output for a single meter.

Summation CTs can be designed with multiple combinations of 1A or 5A inputs depending on system requirements.

Customisable parameters include

1. Current Ratio
2. Class Accuracy
3. Number of feeder inputs
4. Burden (VA rating)
5. Maximum system voltage
6. Frequency

Interposing Current Transformers (Interposing CT)

Interposing CTs are used to match or convert current signals between devices with different current ratings or burden requirements. They are commonly installed when the existing CT output does not match the input requirements of meters, relays, or monitoring equipment.

These CTs provide accurate signal transformation and electrical isolation, ensuring compatibility between different measurement and protection devices.

Key Features

1. High accuracy Class 0.5
2. Designed for AC current transformation
3. 1A secondary output
4. Capable of accepting 5A input signals
5. Durable resin cast construction
6. Supplied with L brackets for easy panel mounting
7. Custom ratios and configurations available
8. Higher accuracy classes available on request

Protection Current Transformers (Protection CT)

Protection CTs are specifically designed for protective relay systems and circuit breaker tripping applications. These CTs are built to accurately reproduce current during fault conditions, ensuring protection relays operate correctly.

Unlike metering CTs, protection CTs must handle very high fault currents without saturating, allowing protection systems to detect abnormal conditions and isolate the fault quickly.

Key Features

1. Available in a wide range of protection accuracy classes
2. Tape wound or resin cast ring-type construction
3. 5A secondary output (1A available on request)
4. M6 or M8 secondary terminal studs for secure connections
5. Designed for high fault current withstand capability
6. Can be customised to required burden ratings and dimensions

Protection CTs are commonly used in:

1. Feeder protection
2. Transformer protection
3. Generator protection
4. Switchgear protection systems

Customisable CT Parameters

All CTs can be manufactured to suit your project requirements with configurable parameters including:

• Current Ratio
• Accuracy Class
• Burden (VA rating)
• Number of feeder inputs
• Maximum system voltage
• Frequency (50 Hz / 60 Hz)
• Core type (split core or solid core)
• Mounting configuration
• Insulation and enclosure design