GCS Low Voltage Draw-Out Switchgear

GCS type low-voltage withdrawable switchgear is suitable for power plant, petroleum, chemical, metallurgy, textile, high-rise building and other industries of power distribution system. In large power plants, petrochemical systems and other high degree of automation, requiring the interface with the computer, as a three-phase AC frequency of 50(60)Hz, rated operating voltage of 400V, 660V, rated current of 5000A and below the power supply system in the distribution, motor centralized control, reactive power compensation of the use of low-voltage complete sets of distribution devices. The design of the device meets the following standards: IEC439-1 “Low-voltage Switchgear and control equipment” GB7251 “Low-voltage switchgear”

Application

GCS type low – voltage draw – out switchgear is applicable to the power distribution systems of industries such as power plants, petroleum, chemical industry, metallurgy, textiles, and high – rise buildings. In places with a high degree of automation like large – scale power plants and petrochemical systems, where interface with computers is required, it is used as a low – voltage complete power distribution device for power distribution, centralized motor control, and reactive power compensation in the power generation and supply systems with a three – phase AC frequency of 50(60)Hz, rated operating voltages of 400V and 660V, and a rated current of 5000A and below.

The design of the device complies with the following standards: IEC439 – 1 “Low – voltage switchgear and controlgear assemblies” and GB7251 “Low – voltage switchgear assemblies”.

Model Meaning

Main circuit scheme number, system draw – out enclosed switchgear

Normal Operating Conditions

• The ambient air temperature is not higher than +40°C and not lower than – 5°C, and the average temperature within 24 hours shall not be higher than +35°C. If exceeded, derating operation is required according to the actual situation.
• It is used indoors, and the altitude of the installation site shall not exceed 2000m.
• The relative humidity of the ambient air does not exceed 50% when the temperature is +40°C. At lower temperatures, a higher relative humidity is allowed. For example, it is 90% at +20°C. The possible occasional condensation due to temperature changes should be considered.
• The inclination of the device from the vertical plane during installation does not exceed 5°, and the entire set of switchgear is relatively flat (in line with the GBJ232 – 82 standard).
• The device should be installed in a place without severe vibration, impact, and where there is no corrosion that could damage the electrical components.
• When users have special requirements, they can negotiate with the manufacturer to solve them.

Main Technical Parameters

Main Circuit Schemes

The GCS switchgear has a total of 32 groups and 118 specifications for the main circuit, excluding the schemes and specifications derived from changes in the control and protection of the auxiliary circuit. It meets the needs of power generation, power supply, and other power users. With a rated operating current of 5000A, it is suitable for power distribution transformers of 2500kVA and below. In addition, a capacitor compensation cabinet is designed to meet the need of power supply users to improve power factor, and a reactor cabinet is designed considering the need for comprehensive investment.

Auxiliary Circuit Schemes

The GCS auxiliary circuit atlas contains 120 auxiliary circuit schemes, divided into two volumes. The upper volume, “AC Operation Part”, has 63 schemes, and the lower volume, “DC Operation Part”, has 57 schemes. The auxiliary circuit schemes in the DC operation part are mainly used in the low – voltage station (substation) systems of power plants and substations. They are applicable to the low – voltage station service systems of units with capacities of 200MW and below and 300MW and above, as well as the general control modes of working (standby) power incoming lines, power feeders, and motor feeders.

The auxiliary schemes in the AC operation part are mainly used in the low – voltage systems of substations in factories, mines, enterprises, and high – rise buildings. There are 6 combined schemes suitable for dual – power operation control. Control circuits such as electrical interlock for operation, standby power automatic switching, and self – restoration are set up, which can be directly adopted in engineering design.

The DC control power is 220V or 110V DC, and the AC control power is 380V or 220V AC. The complete switchgear is composed of drawer units. The 220V control power is supplied from the dedicated control transformer in the switchgear for the common control power. The common control power uses an ungrounded control transformer, and a 24V power supply is reserved for use when weak – current signal lamps are needed.

For details of the installation location of the watt – hour meter, the method of introducing voltage signals, and other installation and usage requirements, please refer to the “Compilation Instructions” of the auxiliary circuit diagram.

Main Busbar

To improve the dynamic and thermal stability of the busbar and reduce the temperature rise at the contact surface, all equipment uses the TMY – T2 series of hard copper busbars. The copper busbars are tin – plated along the entire length, and silver – plated copper busbars along the entire length can also be selected.

The horizontal busbar and vertical busbar are installed in the busbar isolation compartments inside the switchgear respectively. The neutral grounding busbar uses a hard copper busbar. The horizontal neutral grounding conductor (PEN) or the grounding + neutral conductor (PE + N) runs through.

Selection of Electrical Components

The GCS switchgear mainly selects electrical components with stable performance and high indicator values, and those that can be mass – produced in China using imported technologies.

Main Switch

• For power incoming and feeder switches of 630A and above, the DW45 series is the primary choice. The DW48 series, AE series, 3WE or ME series can also be selected. When necessary, the imported M series or F series can be chosen.
• For feeder and motor control switches below 630A, plastic – case switches such as the TG series, CM1 series, NM series, CDM series, and TG30 series are mainly selected.

To improve the dynamic stability of the main circuit, a special combined busbar clamp and insulating support for the GCS series are designed. They are thermoplastically formed from high – strength, flame – retardant synthetic materials, with high insulation strength, good self – extinguishing performance, and a unique structure.

To reduce the temperature rise of the partition boards, connectors, and cable terminals of the functional units, a special adapter for the GCS switchgear is designed. The adapter has a large capacity and can reduce the temperature rise. If the design department selects new electrical components with better performance and more advanced technology according to user needs, due to the good versatility of the GCS series switchgear, the renewal of electrical components will not cause difficulties in manufacturing and installation.