◎Foreword

GCS type low-voltage withdrawable switchgear (hereinafter referred to as the device) is the Ministry of Power Industry and Machinery Industry to promote the technological progress of China's low-voltage power distribution industry, accelerate the upgrading of low-voltage power distribution switchgear, and protect and promote China's national industry. In 1995, Senyuan Electric Co., Ltd. was entrusted to organize two GCS-type low-voltage withdrawable switchgear joint design groups (hereinafter referred to as the two joint groups) to complete the design and development, which has been initially affirmed nationwide. Selection, in order to facilitate the design and use of the unit application, write this manual.

 

◎Scope of application

The device is suitable for power conversion, distribution and control of power, power distribution and motor control centers, capacitor compensation, etc. of low-voltage power distribution systems such as power plants, substations, petrochemical departments, factories and mines, and high-rise buildings.

It can meet the special needs of computer interfaces in power applications such as low-voltage power control centers and motor control centers in large single-unit power plants and large-scale petrochemical industries.

The device is based on the requirements of the supervisors of the Ministry of Electric Power, the majority of power users and the design department. In order to meet the needs of the power market that is not afraid of development, such as capacity expansion, computer interface, centralized power control, convenient installation and maintenance, and shortened accident handling time, The new low-voltage withdrawable switchgear designed with economic, reasonable and reliable principle has the advantages of high breaking, high connection, good thermal stability, flexible electrical scheme, convenient combination, strong seriality, novel structure and high protection level. Features, can be used as a replacement for low-voltage withdrawable switchgear.

The device complies with IEC439 "Low-voltage switchgear and control equipment", GB7251 "Low-voltage switchgear" and other equipment.

 

◎Product model and meaning

 

 

◎Conditions of Use

The ambient air temperature is not higher than +40 °C, not lower than -5 °C, and the average temperature within 24 hours shall not be higher than +35 °C. When it exceeds, it shall be derated according to actual conditions.

For indoor use, the altitude of the place of use shall not exceed 2000m.

The relative humidity of the surrounding air does not exceed 50% at the maximum temperature of +40 ° C, and allows a relatively large relative humidity at a lower temperature, such as 90% at +20 ° C. It should be considered that the temperature may change by chance. The effect of condensation.

When the device is installed, the inclination of the vertical surface is not more than 5 degrees, and the whole set of cabinets is relatively flat (in accordance with GBJ232-82 standard).

The device shall be installed in a location where there is no violent vibration and shock and insufficient to subject the electrical components to undue corrosion.

When the user has special requirements, it can be resolved in consultation with the manufacturer.

 

◎Electrical parameter

Basic electrical parameters

a. rated insulation voltage AC 690/1000V

b. Rated working voltage AC 400690230/400V

c. rated frequency 50 (60) Hz

d. The maximum working current of the main bus is 4000A

e. Vertical busbar maximum working current 1000A

f. Main bus short-time (1S) withstand current (RMS) 100KA

g. Main bus short-time withstand peak current (maximum) 250KA

h. Vertical busbar short-time withstand current 50KA

i. Vertical busbar short-time withstand peak current (maximum) 125KA

j. Protection grade IP30, |P40, P54 (when ordering P54 protection grade, you must contact the manufacturer in time)

 

Main circuit scheme

The main circuit solution was selected from the opinions of the design, manufacturing, testing and use departments, including power generation, power supply and other power users. The maximum rated working current is 4000A, suitable for 2500K∨A and below. Electric transformer selection.

In addition, a capacitor compensation cabinet is designed to meet the needs of power supply to improve the power factor.

 

Auxiliary circuit scheme

The auxiliary circuit scheme of the DC operation part is mainly used for the low-voltage plant (station) system of the power plant substation; it has been considered to be suitable for the low-voltage factory system of 200MWW and below and 300MW and above capacity units, working (standby) power supply line, General control of power feeders and motor feeders.

The auxiliary scheme of the AC operation part is mainly used for low-voltage systems of substations in factories and mines and high-rise buildings. There are 6 combinations suitable for operation control of variable power supply lines. It also has control circuits for operating electrical interlocking, self-injection, self-recovery, etc., which can be directly used in engineering design.

The DC control power supply is DC 220V and 110V, the AC control power supply is AC 380V or 220V, and the complete set of cabinets consisting of drawer units 220∨ control power is taken from the common control power supply of the special control transformer power supply in the cabinet. The common control power supply is not grounded. The transformer is controlled and a 24V power supply is reserved for use when a weak electric signal lamp is required.

 

Bus bar

A. horizontal bus

The horizontal busbar is placed in the busbar compartment at the rear of the cabinet. The 3150A and above are double-layered, and the 2500A and below are single-layer layout.

b. Vertical bus

The vertical busbar for the chest of drawers uses an "L" shaped hard copper bismuth busbar.

L type busbar specification (mm)

(height x thickness) + (bottom x thickness) = (50 x 6) + (30 x 6), rated current 1000A.

 

◎Structural features

The main frame of the device is made of 8MF steel, and the frame is assembled and partially welded.

The main frame is equipped with a modulus hole E=20mm.

The functional rooms of the device are strictly separated, and the compartments are mainly divided into functional unit rooms, busbar rooms and cable rooms, and the functions of the units are relatively independent.

The horizontal main busbar is placed at the rear of the cabinet, so that the cable compartment has an outlet passage above and below, which solves the problem that the old product cannot be taken out.

The size series of the round cabinet is as follows

 

 

Functional unit

a. A drawer is an independent functional unit.

b. The drawer is divided into two series of one-half unit, one unit, two unit and three units. The rated current of the circuit is 630A or below.

The size of a unit drawer is: 160 (height) × 560 (width) × 470 (deep), the width of one-half unit drawer is 280, and the two-unit and three-unit are only doubled and tripled in height. The remaining dimensions are all in the same unit.

c. The drawer of the functional unit can be easily interchanged

d. Each unit of the device can be equipped with 11 one-unit drawers or 22 one-half unit drawers.

e.Drawer in and out line adopts the same specification chip connector with different number of pieces according to the loop current. Generally, one piece of connector is ≤200A

f. One-half drawer and cable room transfer, using a backplane-type adapter, and the unit drawer and cable compartment are transferred using a rod-shaped adapter.

g. The drawer panel has obvious signs of joint, break, test and extraction, etc. The drawer is provided with mechanical interlocking device, as shown in Figure 1 and Figure 2.

The feeder cabinet and the motor control cabinet are provided with a dedicated cable compartment, and the connection between the functional unit room and the cable compartment cable is realized by the adapter or the copper busbar, which improves the reliability of the cable and is extremely convenient. User installation and maintenance of the cable. The cable compartment is available in two width sizes (240mm and 440mm) depending on the number of cables, the cross section and the user's ease of installation and maintenance.

The functional unit auxiliary contact pairs of the device are 32 pairs for one unit and above, and 20 pairs for 1/2 units, which can meet the needs of automation users and interfaces with computers.

Considering the generality and safety of dry-type transformers and the economics of oil-immersed transformers, the device can be conveniently combined with dry-type transformers or with low-voltage busbars of oil-immersed transformers.

The main body of the drawer is of the pull-out type and the fixed type, and can be mixed and combined, and can be selected as a fixed partition.

The device is designed according to three-phase five-wire system and three-phase four-wire system. The design department and users can conveniently select PE+N or PEN mode.

The degree of protection of the cabinet is |P3X, P4X, and can also be customized according to user needs.

 

 

◎Installation and use

After the product arrives at the receiving location, it should first check whether the packaging is intact. If problems are found, the relevant departments of the contract should be notified in time to make business records, analyze the reasons together, and make visas and aftercare.

For products that are not installed immediately, they should be placed in an appropriate place according to normal use conditions or electrical equipment temporary storage regulations, and kept in a safe place.

 

Product installation

The installation of the product shall be carried out according to the installation diagram (see Figure 3). The bolts for the basic channel steel and the bolt fixing method shall be provided by the user. When the main busbar is connected, if the surface is uneven due to transportation, storage, etc., it shall be added. After the flatness, connect and fasten.

 

Inspection and test before commissioning of the product after installation

a. Check the cabinet finish or other covering materials (such as spray) for damage, and whether the cabinet is dry and clean.

b. Whether the operating mechanism of electrical components is flexible, there should be no stuck or excessive operating force

c. Whether the main and auxiliary contacts of the main electrical equipment are reliable and accurate.

d. Drawers or draw-out mechanisms should be flexible, lightweight, free of jams and collisions.

e. The center line of the moving and static contacts of the drawer or withdrawable structure shall be consistent, the contact of the contacts shall be tight, the insertion depth of the main and auxiliary contacts shall meet the requirements, and the mechanical interlock or electrical interlocking device shall operate correctly, and the locking shall be performed. Or release should be reliable.

f. Drawers of the same size should be easily interchangeable without jamming or collision.

g. The grounding contact between the drawer and the cabinet should be in close contact. When the drawer is pushed in, the grounding contact of the drawer should be in contact with the main contact first. When the drawer is pulled out, the procedure is reversed.

h. The scale setting of the meter, the ratio of the transformer and the polarity are correct.

i. The fuse core specifications shall comply with the engineering design requirements.

j. The setting and setting of relay protection should be correct and the action is reliable.

k. Use a 1000V megger to measure the insulation resistance value not less than 1MΩ.

l. The connection of each busbar should be good, and the installation of insulating supports, mounting parts and other accessories should be firm and reliable.

 

Precautions for use

a. GCS series cabinets are low-voltage power distribution cabinets that are not installed by wall, frontal operation, double-sided maintenance, maintenance passages and cabinet doors of the cabinets, which must be qualified professionals to enter or open for operation, inspection and maintenance.

b. The air circuit breaker and the molded case circuit breaker are divided and combined many times, especially after short-circuiting and closing, which will cause partial burns of the contacts and carbon materials, so that the contact resistance increases, and the circuit breaker should be used. Carry out maintenance and overhaul.

C. After installation and maintenance, the compartments must be strictly inspected. The isolation between the functional units has indeed been restored to ensure good functional separation of the unit and to prevent fault expansion.

 

◎Product set

The following documents and accessories should be provided at the time of manufacture.

Packing List

Product certification

user's manual

Factory test report

Related electrical drawings

Door key, operating handle and contracted spare parts

Installation and operation instructions for main components

 

◎ Ordering Information

The user provides the following information:

1. Main circuit scheme and combination arrangement

2. Auxiliary circuit control and wiring principle

3. The layout of the switchgear in the distribution room

4. Incoming and outgoing lines and interface requirements

5. Detailed models and specifications of components installed in the cabinet

6. Switch cabinet surface treatment and color

7. Other special requirements (if any).