Product Introduction
GCS low-voltage draw-out switchgear is applicable to power distribution systems in power plants, petroleum, chemical, metallurgy, textile, high-rise buildings and other industries. In places with high degree of automation, such as large power plants and petrochemical systems, where computer interface is required, it is a low-voltage complete power distribution device used for power distribution, motor centralized control and reactive power compensation in power generation and power supply systems with three-phase AC frequency of 50 (60) Hz, rated working voltage of 400V, 660V and rated current of 5000A and below.
The design of the device complies with the following standards: IEC439-1 Low-voltage Switchgear and Control Equipment and GB7251 Low-voltage Switchgear.
Working conditions
◇ The ambient air temperature shall not be higher than+40 ℃, not lower than - 5 ℃, and the average temperature within 24 hours shall not be higher than+35 ℃. In case of exceeding, the capacity shall be reduced according to the actual situation;
◇ For indoor use, the altitude of the place of use shall not exceed 2000m;
◇ The relative humidity of the surrounding air shall not exceed 50% when the upper limit temperature is+40 ℃. A relatively high relative humidity is allowed at a lower temperature, such as 90% at+20 ℃. The influence of condensation may occur occasionally due to temperature changes shall be considered;
◇ When the device is installed, the inclination from the vertical plane shall not exceed 5 °, and the whole set of cabinet columns shall be relatively flat (in accordance with GBJ232-82 standard);
◇ The device shall be installed in a place without severe vibration and impact and not enough to make electrical components subject to corrosion;
◇ When users have special requirements, they can negotiate with the manufacturer.
Main technical parameters
See Table 1 for basic technical parameters
◆ Main circuit scheme
The main circuit scheme of GCS cabinet has 32 groups and 118 specifications, excluding the scheme and specification derived from the change of control and protection of auxiliary circuit. It covers the needs of power generation, power supply and other power users. The rated working current is 5000A, which is applicable to the selection of distribution transformers of 2500kVA and below. In addition, the capacitor compensation cabinet is designed to meet the need of power supply and consumption to improve power factor, and the reactor cabinet is designed considering the need of comprehensive investment.
◆ Auxiliary circuit scheme
There are 120 auxiliary circuit schemes in GCS auxiliary circuit atlas, which are divided into two volumes. The first volume of AC Operation Part is divided into 63 schemes, and the second volume of DC Operation Part is divided into 57 schemes.
The auxiliary circuit scheme of the DC operation part is mainly used for the low-voltage plant (substation) system of the power plant substation. It is applicable to the general control mode of low voltage auxiliary system, working (standby) power incoming line, power feeder and motor feeder of units with capacity of 200MW and below and 300MW and above.
The auxiliary scheme of the AC operation part is mainly used for the low-voltage system of substations in factories, mines, enterprises and high-rise buildings. There are 6 combination schemes suitable for dual power operation control. It is also equipped with control circuits such as operation electrical interlocking standby automatic switch and automatic reset, which can be directly used in engineering design.
The DC control power supply is DC 220V or 110V, and the AC control power supply is AC 380V or 220V, which is a complete cabinet composed of drawer units. The 220V control power supply is from the public control power supply supplied by the special control transformer in the cabinet. The public control power supply uses the ungrounded control transformer, and the 24V power supply is reserved for use when the weak current signal lamp is needed.
For the installation location of the watt-hour meter, the introduction method of voltage signal and other installation and use requirements, see the Preparation Instructions of the auxiliary circuit diagram.
◆ Main bus
In order to improve the dynamic and thermal stability of the bus and improve the temperature rise of the contact surface, the equipment adopts TMY-T2 series hard copper bar, the copper bar adopts full-length tinning, or full-length silver-plated copper bus.
◇ Horizontal bus and vertical bus are installed in the bus isolation room in the cabinet.
◇ The neutral grounding bus adopts hard copper bar. Through horizontal neutral grounding wire (PEN) or grounding+neutral wire (PE+N).
◆ Selection of electrical components
The GCS cabinet mainly selects electrical components with high technical performance stability index value and imported technology that can be produced in batches in China.
◇ Main switch
For power incoming and feeder switches of 630A and above, DW45 series is the main choice, DW48 series, AE series, 3WE or ME series can also be selected, and M series or F series can also be selected if necessary.
◇ For feeder and motor control switches below 630A, TG series, CM1 series, NM series, CDM series, TG30 series and other molded case switches are mainly selected.
◇ In order to improve the dynamic stability of the main circuit, the GCS series special combined bus clamp and insulation support are designed, which are made of high-strength and flame-retardant synthetic material thermoplastic molding, with high insulation strength, good self-extinguishing performance and special structure.
◇ In order to reduce the temperature rise of the spacer plate, connector and cable head of the functional unit, a special adapter for GCS cabinet is designed, with large capacity and low temperature rise.
◇ If the design department selects new electrical components with better performance and more specialized technology according to the needs of users, the GCS series cabinet has good versatility and will not cause difficulties in manufacturing and installation due to the renewal of electrical components.
Installation and use
After the product arrives at the receiving place, it is necessary to check whether the package is intact. If any problem is found, it is necessary to notify the relevant departments of the contract in time to make business records, analyze the causes together, and make evidence collection and aftermath treatment. For products that are not installed immediately, they should be placed in a proper place and properly stored according to normal use conditions and temporary storage regulations for electrical equipment.
◆ The installation of products should be carried out according to the installation diagram. The foundation channel steel and the bolts used for bolt fixation shall be prepared by the user. When the main bus is connected, if the surface is uneven due to transportation, storage and other reasons, it should be leveled before connecting and fastening.
◆ When the equipment is installed separately or in rows, its perpendicularity and the deviation of the cabinet surface unevenness and the gap between cabinets shall comply with the provisions of Table 3.
◆ Inspection and test after installation and before operation
◇ Check whether the cabinet surface paint or other covering materials (such as plastic spraying) are damaged and whether the cabinet is dry and clean.
◇ Whether the operating mechanism of electrical components is flexible and free from jamming or excessive operating force.
◇ Whether the main electrical appliances are reliable and accurate.
◇ The drawer or draw-out mechanism shall be flexible, portable and free from jamming and collision.
◇ The center line of the dynamic and static contacts of the drawer or draw-out structure should be consistent, and the contact should be tight. The insertion depth of main and auxiliary contacts shall meet the requirements. The mechanical interlocking or electrical interlocking device shall act correctly, and the locking or unlocking shall be reliable.
◇ Drawers with the same primary scheme, secondary principle and drawer size shall be easily interchangeable without jamming and collision.
◇ When replacing the fuse core of the fuse, it should meet the requirements of the engineering design.
◇ The setting value of protection shall be set correctly according to the actual load.
◇ The insulation resistance measured with a 1000V megger shall not be less than 10M Ω.
◇ The connection of each bus shall be good, and the insulation support, installation parts and other accessories shall be installed firmly and reliably.
◆ Precautions for use
◇ The equipment is a low-voltage distribution cabinet that is not installed against the wall, operated in front and maintained on both sides. Only qualified personnel can enter or open the maintenance access and door of the cabinet for operation, inspection and maintenance.
◇ The air circuit breaker and molded case circuit breaker will be partially burned and produce carbon substances after many times of opening and closing, especially after short circuit opening and closing, which will increase the contact resistance. Maintenance and repair should be carried out according to the circuit breaker operating instructions.
◇ After installation and maintenance, the isolation between compartments and functional units must be strictly checked to ensure the good functional separation of the device and prevent the expansion of fault.
◆ Operation of drawer
◇ 1/2 drawer operation
The operating mechanism of the drawer is composed of a rotating part, a rotating shaft, a lock catch, etc., and has the functions of opening and closing, testing, isolation and locking of the switch. The operating mechanism is also equipped with a microswitch for electrical locking.
Factory data and accessories
◆ The manufacturer shall provide the following documents and accessories when supplying
◇ Delivery list
◇ Product certificate and delivery test report
◇ Operation instructions
◇ Relevant electrical drawings
◇ Description of main components
◇ Cabinet door key, operating handle and spare parts specified in the contract
Ordering instructions
◆ When ordering, users should provide:
◇ Main circuit distribution system diagram and layout plan, rated working voltage, rated working current, protective device setting current and necessary technical parameters.
◇ Indicate the specifications of incoming and outgoing cables.
◇ Model, specification and quantity of main electrical components in the switch cabinet.
◇ If bus bridge or bus duct is required between switch cabinets or incoming cabinet, specific data such as span, height from ground, etc. shall be indicated.
◇ When the switch cabinet is used under special environmental conditions, it shall be explained in detail when ordering.
◇ Surface color of switch cabinet and other specific requirements.
