In modern low-voltage power distribution systems, protective current transformers play a crucial role in ensuring electrical safety, relay accuracy, and reliable fault detection.

For electrical equipment manufacturers, control panel builders, and industrial automation engineers, selecting the right protective current transformer is critical to the stable operation of protective relays, motor control centers (MCCs), and distribution bus systems.

The HPT series of protective current transformers is designed for use in low-voltage protection systems that require accurate short-circuit current detection and reliable relay operation.

What is a protective current transformer?

A protective current transformer (CT) is a type of current transformer used primarily for the following purposes:

relay protection

The Palace of the Circle revealed

Overcurrent monitoring

Incorrect insulation

Protection of electrical systems

Unlike standard current transformers, which ensure measurement accuracy under normal operating conditions, protective current transformers are designed to maintain accuracy even in the event of faults and high currents.

This is extremely important in the following aspects:

• Low voltage switches
• MCC Committee
• Electrical distribution cabinet
• Industrial motor control system
• Tire protection system

 

Why are protective current transformers so important in low-voltage switching equipment?

In modern switching systems, protective relays rely on stable and accurate current signals.

If the current transformer becomes saturated prematurely due to a fault, the relay may not function correctly:

• The Palace of the Circle revealed
• The circuit breaker failed.
• Rear equipment protection

This may lead to the following:

• Device malfunction
• electrical fire
• Unexpected closure
• relay malfunction
• HPT series current transformer protection devices ensure reliable power transmission even under high short-circuit currents.

Features of the HPT Protective Current Converter

The HPT series has been optimized for switching and protection devices that require a compact design, stable operation, and ease of installation.

Key Features

• Specifically designed for low-voltage protection systems.
• Suitable for use in phased protection systems.
• High short-circuit resistance
• Stable operation under short-circuit current
• Small window design
• It can be easily installed in a distribution cabinet.
• Suitable for busbar systems and multi-cable systems.
• Reliable thermal insulation properties.

 

Typical applications of high-voltage current transformers

HPT series products are widely used in the following fields:

• Low voltage switches
• It is used to detect the current in the protective relays of low-voltage distribution panels.
• MCC Committee

Suitable for motor control centers that require protection against overload and short circuits.

Tire protection system

The wide window design allows for flexible mounting options around copper busbars or multi-conductor busbars.

Industrial automation

It is used in factories, process control systems, and for monitoring industrial energy consumption.

Energy and infrastructure projects

Target audience:

• Solar power generation system
• Electric vehicle charging system
• commercial building
• Data processing center
• Smart power distribution system

 

Preventive computed tomography and dose computed tomography

Many engineers ask themselves the following question:

What is the difference between protective current transformers and standard current transformers?

The answer lies in its practical use.

Jobs	Protection of computed tomography (CT) scans	Standard computed tomography
Main objective	relay protection	Energy measurement
Controlling short-circuit current	great	end
Saturation requirements	Delay saturation	Feeling full too early
precise focus	strong current	Normal operating conditions
A typical classroom	5P10 / 10P10	Difficulty level 0.5 / 1.0

HPT series protective current transformers are specifically designed to maintain reliable relay signals even under abnormal current conditions.

What does the abbreviation 5P10 mean in the context of preventive computed tomography (CT) scanners?

One of the most frequently asked questions by engineers online:

What does the code 5P10 on a power adapter mean?

The explanation is as follows:

5P = Protection accuracy level

10 = Height Limit Factor (ALF)

This means that the current transformer can maintain protection accuracy within a range of ten times the rated current without excessive errors.

Commonly used shielded computed tomography (CT) scanners include:

• 5P10
• 5P20
• 10P10
• 10P20

The appropriate classification depends on the following:

• relay type
• Short-circuit current level
• Download requirements
• Designing a security system

 

How to choose the right CT scanner

Choosing the right protective current transformer is crucial to ensuring the reliability of the relay.

Key selection criteria

1.Liquidity ratio

example:

100/5 A

200/5A

400/5 A

This ratio must be adjusted to match the system load and the input requirements of the relay.

 

2.Degree of accuracy

Common types of security systems include:

5P10

5P20

10P10

More stringent protection requirements typically require a higher Auto-Activation Factor (ALF).

 

3.Window dimensions

The following conditions must be met before operating the computed tomography (CT) scanner:

• Bar bus
• power cable
• Several cables
• The HPT series is suitable for integrated control cabinets and busbars.

 

4.Load-bearing capacity

The total price includes the following:

• relay consumption
• cable resistance
• The connection was lost.
• Choosing the wrong shipment may compromise the accuracy of the protection.

 

Why do electrical appliance manufacturers prefer to use protective current transformers in window manufacturing?

Window-type protective current transformers are frequently used in low-voltage electrical distribution panels due to the following advantages:

• Compact installation
• Easy-to-install frames
• Simplify the process of connecting cables.
• More efficient use of space
• Rapid assembly during panel manufacturing

The HPT series is particularly suitable for original equipment manufacturers (OEMs) and control cabinet manufacturers looking for reliable protection solutions.

 

Common problems that arise from choosing the wrong computed tomography (CT) scan method.

Using an inappropriate scanner could pose a serious security risk.

Frequently Asked Questions

CT scan saturation in the presence of defects

relay malfunction

imaginary trip

Inaccurate error detection

High temperature inside the control cabinet.

Choosing the right scanner security system can help improve the following:

• System reliability
• Protection accuracy
• Device lifespan
• Electrical safety

 

High voltage protection transformer in modern power distribution systems

As modern electrical systems become more intelligent and smaller, protective current transformers must ensure the following:

Stable protective effect

small size

Flexible installation

Long-term reliability

The HPT series of protective current transformers is designed to meet the requirements of modern applications:

Electrical equipment manufacturers

Record production companies

Industrial Automation Systems Integrator

Energy infrastructure projects

 

In conclusion

Protective current transformers are essential components of modern low-voltage protection systems.

For manufacturers and engineers of electrical equipment, choosing the right protective current transformer has direct implications for the following aspects:

• Reliability of retransmission
• Accuracy in fault detection
• Electrical safety
• System stability in general

The HPT series of protective current transformers provides reliable solutions for protecting low-voltage relays, electrical switchgear, and industrial power distribution systems.

If you need a compact and reliable protective current transformer for use in electrical distribution boxes or busbars, the HPT series is ideal for modern electrical protection systems.

Compay：HEYI Electrical Co., Ltd.
Brand: HEYI/ASCT
Contact: Bethy
E-mail: heyi@heyiele.com             
Tel: 86-13968747975

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