HXGN17-12 Ring Main Unit Product Introduction

1. Product Brief Introduction

The HXGN17-12 type fixed AC metal-enclosed switchgear (referred to as ring main unit) is an AC high-voltage switchgear assembly with a rated voltage of 12kV and a rated frequency of 50Hz. It is mainly used in three-phase AC ring networks, terminal distribution networks and industrial and mining electrical equipment for receiving, distributing electrical energy, and it is also suitable for being installed in box-type substations.

2. Model Meaning & Explanation

The coding of the product model contains the core structural characteristics and parameter information of the ring main unit. The specific meaning of each part of the model is as follows:

HXGN□-12(□·R)/□
├─□: Rated current (A)
├─/: Fuse
├─R: SF6 load switch
├─Z: Vacuum load switch
├─No mark: Pneumatic load switch
├─12: Rated voltage (kV)
├─□: Design serial number
├─N: Indoor use
├─G: Box-type structure
└─HX: Ring main unit

3. Operating Environmental Conditions

• Ambient air temperature: -15℃ ~ +40℃;
• Altitude: 1000m and below;
• Humidity conditions: Daily average value not more than 95%, average value of water vapor pressure not more than 2.2kPa; Monthly average value not more than 90%, average value of water vapor pressure not more than 1.8kPa.
• Seismic intensity: Not exceeding 8 degrees;
• No places with obvious pollution of corrosive or flammable gases, etc.
• If used beyond the above normal conditions, users can negotiate with our company.

4. Main Technical Parameters of Vacuum Circuit Breaker

5. Main Technical Parameters

6. Installation, Storage, Transportation and Acceptance

  6.1 Packaging, Storage and Transportation

• The ring main unit is packaged in single wooden cases when leaving the factory. It is not allowed to be tilted, inverted or subjected to severe vibration during transportation; it is not allowed to be directly pushed and pulled on the ground during moving; when there is no lifting device, round logs can be placed under the packaging wooden case to slide it to the installation position.
• Prevent the cabinet from being exposed to rain and damp.
• The ring main unit should be placed in a well-ventilated place where various harmful gases can be prevented from entering. It is strictly prohibited to store it in the same warehouse with chemicals, acids, alkalis, etc.

  6.2 Acceptance

• Check whether the packaging is damaged before unpacking, and pay attention to protecting the product when unpacking.
• Conduct external inspection on the cabinet body; at the same time, check whether all components in the cabinet are damaged and whether the accessories are consistent with the packing list.
• Check whether the random documents are complete:
  • a. Product instruction manual and instruction manuals of each internal component;
  • b. Factory test report;
  • c. Product qualification certificate;
  • d. Packing list;
  • e. Secondary wiring diagram.

  6.3 Installation and Commissioning

• During installation, first place the ring main unit on the installation foundation, arrange and debug it neatly, then fix it with fasteners.
• When installing the main busbar, open the busbar chamber cover, connect the busbars with flat and clean contact surfaces without dirt.
• The earthing of the ring main unit should be reliably earthed, and the earthing circuit should be checked.
• Commissioning should be carried out in accordance with the instruction manual of the ring main unit and each internal component.
• After installation and commissioning, perform 5 operations on each switch element and anti-misoperation mechanism of the switchgear. If no abnormal phenomenon is found, the mechanical operation of the switchgear is considered normal.

  6.4 Use and Fault Handling

        6.4.1 Pre-operation Inspection

Before putting into operation, comprehensively check the electrical performance, insulation level and wiring correctness of all components in the ring main unit cabinet. Only when everything is normal can it be put into operation.

        6.4.2 Normal Operation Status

During normal operation, the load switch should be in the closed position, the earthing switch should be in the open position, and the cabinet body should be in the closed and locked state regardless of incoming or outgoing lines.

       6.4.3 Fault Handling

• When overhauling due to faults in the incoming line cabinet, first cut off the incoming power supply, open and close the load switch, check the live display on the cabinet at the same time, confirm there is no error, then close the earthing switch and open the front door for overhaul.
• When overhauling due to faults in the outgoing line cabinet, first open the load switch in the cabinet, close the earthing switch, open the front door for overhaul. At this time, the main busbar is in a live state.

        6.4.4 Maintenance and Inspection

The ring main unit needs maintenance and inspection under the following circumstances:

• a. Check the insulation level of the product after 5 years of operation;
• b. After the load switch is opened and closed 100 times, check the main circuit resistance, the opening and closing contacts, static contacts and auxiliary contacts of the load switch;
• c. Generally, maintenance and inspection of the ring main unit should be carried out after power failure.