PT Handcart for 12kV KYN28 Switchgear | Voltage Transformer Unit

The mid-mounted PT handcart, also known as a withdrawable voltage transformer unit, is a critical component of 12kV metal-clad switchgear like KYN28A-12 and HXGN-12. It allows safe and reliable metering, relay protection, and voltage detection by integrating a voltage transformer (VT) in a plug-in, withdrawable structure.

🔧 Product Overview

This unit is designed to accommodate standard voltage transformers such as JDZX10-12 or JDZXF12-YH, commonly used in power systems for 12kV voltage measurement. The handcart enables tool-free maintenance and quick replacement without de-energizing the entire switchgear panel.

Key Features:

• Mid-mounted, fully withdrawable structure

• Equipped with 1-phase or 3-phase PT (voltage transformer)

• Compatible with JDZX10-12, JDZXF12-YH types

• Manual racking mechanism with interlock

• Suitable for KYN28A-12, HXGN-12, and OEM cabinets

• Clear disconnection point for maintenance safety

📐 Technical Specifications

🧰 Typical Applications

• Installed in KYN28A-12 switchgear compartments

• HV substations for voltage metering and relay input

• Medium-voltage control rooms in industrial plants

• OEM panels used by Schneider, ABB, Siemens (with adjustment)

📊 Real Case: PT Handcart Retrofit in Vietnam Textile Mill (2022)

A medium-voltage distribution system in Bắc Giang Province, Vietnam, upgraded its fixed-type voltage transformers to withdrawable PT handcarts in 2022. The project used over 30 mid-mounted PT units with JDZX10-12 VTs to improve safety and enable fast inspection.

Results:

• Reduced maintenance downtime by 60%

• Improved system insulation reliability

• Allowed live-line visual disconnection for technician safety

Source: Vietnam National Grid Technical Bulletin, 2022

🛠 Installation Tips

• Ensure rail size matches cabinet guide slots (210mm or 275mm)

• Always ground VT shield before energization

• Insert the handcart fully before engaging secondary connections

• Use the interlock test procedure to avoid hot insertion

• Clean plug-in contacts annually to prevent oxidation

❓ Frequently Asked Questions (FAQ)

1. What’s the difference between a PT handcart and a metering drawer?
The PT handcart includes a voltage transformer and insulation mechanism, while a metering drawer only contains instruments or wiring.

2. Can this be used in Schneider RMU cabinets?
With adapter rails or OEM modification, yes. Many Schneider and Siemens switchgear systems use similar VT modules.

3. Is this unit arc-proof?
No, but it can be used in arc-proof cabinets. The handcart itself is not arc-resistant.

4. How do I select the correct PT model for this cart?
Common types are JDZX10-12 and JDZXF12-YH, selected based on voltage class and output ratio.

5. Can I customize this unit with SCADA or FTU?
Yes, we offer options for FTU installation and Modbus/IEC61850 communication interface.

📞 Request Layout, Price, or Technical Drawing

We offer technical drawings, OEM services, and retrofit support for global clients.

• Engineer: Thor

• Company: Wei Shoe Elec

• Phone: +86-0577-62788197

• WhatsApp: +86 159 5777 0984

• Email: [email protected]