Low-voltage distribution panel
Products for converting and configuring electrical power
The low-voltage distribution cabinet is equipped with a power distribution system rated for alternating current at 50Hz and a rated voltage of 380V, used for power, lighting, and electrical energy conversion and control. This product features strong breaking capacity, good thermal and mechanical stability, flexible electrical design, ease of assembly, strong series and practicality, and a novel structure.
Current Development Status
1: Low-voltage complete switchgear and control equipment, commonly known as low-voltage switch cabinets, or low-voltage distribution cabinets, refers to a complete set of electrical equipment with alternating and direct current voltages below 1000V.
2: The low-voltage distribution cabinet market in our country has been maintaining a rapid growth trend with the construction of smart grids, infrastructure, investment in the manufacturing sector, and development of the new energy industry.
3: Monitoring data shows that in 2010, the total sales of China's low-voltage distribution box market reached 106.33 billion yuan, with a year-on-year increase of 11.2%; in 2011, the total sales of the low-voltage distribution box market in our country reached 119.60 billion yuan, with a year-on-year increase of 12.5%.
4: With a strong demand for low-voltage distribution cabinets in our country, internal industry competition will intensify. Suppliers offering the latest low-voltage equipment and system solutions will gain a competitive edge in the future market. Only products with the aforementioned features can secure a certain advantage in future competition, thereby occupying the commanding heights of the fourth-generation low-voltage electrical products.
Product Variety
GCS Container
Primary Structure
The main structure is made of 8MF type open steel sections, with mounting holes of 9.2mm diameter on the side of the steel sections, respectively at 20mm and 100mm module.
2: The functional compartments of the equipment are isolated from each other, with the compartments divided into functional unit rooms, busbar rooms, and cable rooms. The functions of each room are independent of one another.
3: The horizontal main busbar is arranged in a flat placement behind the cabinet to enhance its resistance to electromagnetic forces.
The design of the cable compartment facilitates the easy up and down entry and exit of cables.
Functional Unit
Drawer height modular 160mm, unit circuit rated current 400A and below
GCK Container: (MCC)
Primary Structure
GCK(L) Type Low-Voltage Distribution Box
GCK(L) Low-Voltage Distribution Box
The cabinet's basic structure is a modular assembly. Bolted connections isolate individual function rooms with 20mm modular mounting holes. The primary feature of the GCK cabinet is that the busbars are located at the top of the cabinet, with its compartments divided into functional unit rooms (in front of the cabinet), busbar rooms (at the top of the cabinet), and cable rooms (at the back of the cabinet). It can also be mounted against a wall, in which case, the right side of the cabinet is widened by 200mm to accommodate the cable room, making it similar in busbar style to the top of an MNS cabinet.
Function Unit
Drawer height modular 200mm
MNS Container: (MCC)
Primary Structure
MNS Type Distribution Cabinet
MNS Type Distribution Box
1: The basic structure of the cabinet is assembled from C-shaped profiles. The C-shaped profiles are bent from steel plates with mounting holes in a module of E=25mm.
2: The pull-out MCC cabinet is divided into three compartments, which are the function unit compartment (left front of the cabinet), busbar room (rear of the cabinet), and cable room (right front of the cabinet). As the horizontal busbar compartment is located at the rear, it can also be designed as a double-sided cabinet.
3: Designed to reduce the width of switchgear arrangement, the rear outlet design of the switchgear has the main busbar horizontally installed at the top of the switchgear, with the rear half serving as the cable room. At this point, it resembles the busbar style of the GCK cabinet.
GGD Container: (ESS)
Electrical Performance:
1) Basic Electrical Parameters
GGD type low-voltage distribution box
GGD Type Low-Voltage Distribution Box
A) Rated Insulation Voltage: AC 660V (1000V) B) Rated Working Voltage: Main Circuit: AC 380V (660V); Auxiliary Circuit: AC 380V (220V) DC 220V (110V)
C) Rated Frequency: 50Hz
D) Rated Current: ≤4000A
E) Rated Peak Current Tolerance (0.1s) 105KA
F) Rated Short-Time Current Tolerance (1s) 50KA
The GCK series AC low-voltage distribution boxes are recognized as a new energy-saving product by the state. They feature an advanced control center structure, attractive appearance, high electrical performance, high protection level, safety, reliability, and easy maintenance, making them an ideal power distribution unit for low-voltage power supply systems in industries such as metallurgy, petrochemicals, chemical engineering, electrical machinery, and light industry textiles.
Primary Technical Performance
b) Rated Working Voltage: 380V, 660V
c) Frequency of Use: 50Hz
d) Rated Current: Horizontal Busbar System 1600-3150A, Vertical Busbar System 400-800A
e) Rated Short-Time Current Withstand: Horizontal Bus 80KA RMS/1 second, Vertical Bus 50KA RMS/1 second
f) Rated Peak Current: Horizontal Bus 175KA, Vertical Bus 110KA
g) Functional Unit Breaking Capacity: 50KA
h) Peripherals Protection Grade: IP40
PGL cabinet:
The PGL type AC low-voltage distribution cabinet is suitable for power users such as power plants, sub-stations, and industrial and mining enterprises in distribution systems for AC 50Hz, rated working voltage 380V, and rated current up to 2500A, where it is used for power conversion, distribution, and control of power, lighting, and distribution equipment. This product has a high breaking capacity, with a rated short-time withstand current of up to 50kA.
This product complies with standards IEC439 for Low-voltage switchgear and controlgear, GB7251 for Low-voltage switchgear and controlgear, etc.
The PGL electrical distribution cabinet is designed for indoor installation, featuring an open, double-sided maintenance low-voltage distribution unit. The basic structure of the cabinet is composed of steel plates and angle iron welded together. The front of the cabinet has a door, and above the cabinet there is a control panel, which is a removable small door to accommodate indicator instruments. Parallelly assembled cabinets are equipped with partitions between them, reducing the possibility of an accident expanding due to a fault within a single cabinet. Above the rear frame of the cabinet, the main busbars are installed on sub-insulating frames, and a busbar protective cover is provided to prevent metal objects from falling above and causing a catastrophic short circuit in the main busbars. The neutral busbar is mounted on insulators below the cabinet, and the main grounding point of the grounding system is welded below the frame. The instrument door also has a grounding point connected to the housing.
PGL type AC low-voltage distribution panels are divided into: low-voltage metering cabinets, low-voltage incoming line cabinets, capacitor compensation cabinets, on-grid-to-off-grid conversion cabinets, bus connection cabinets, and low-voltage outgoing line cabinets.
Main Technical Parameters:
Rated Voltage: AC 380V
Rated Breaking Capacity:
PGL1：15KV
PGL2: 30KV (all are RMS values)
Rated voltage of auxiliary circuit:
AC220V、380V
DC110V、220V
Rated Current:
2000A，2500A
Maintenance Instructions
Maintenance of low-voltage distribution cabinets primarily ensures their normal and safe operation. A comprehensive annual inspection and maintenance should be carried out for low-voltage distribution cabinets. Repairs should be completed with minimal power outages, generally scheduling the owner's downtime in advance.
Maintenance Content and Steps for Low-Voltage Distribution Panels:
1: Start the inspection from the low-voltage side of the transformer. After the distribution cabinet is de-energized, clean the dust inside the cabinet, check if the busbars and down leads are well connected, if there is any overheating or discoloration at the joints, ensure the cable ends and terminal connections are secure and reliable, inspect for rust on the grounding wires, and make sure the terminal connections are tight. All secondary circuit wiring connections should be reliable and the insulation should meet requirements.
2: When inspecting the drawer-type switch, the drawer cabinet should operate smoothly upon pushing in or pulling out, with a reliable mechanical lock. Check if the operating mechanism of the automatic air switch on the drawer cabinet is in place and if the wiring screws are tight. Clean the surface and surroundings of the contactor contacts, inspect the contactor contacts for proper contact. If the contacts are not making good contact, lightly file the contact surface if necessary. If the contacts are severely burned (worn down to 1/3 of the original thickness), they should be replaced. The power indicator gauge and indicator lights are in good condition.
3: When overhauling the capacitor cabinet, first disconnect the main switch of the capacitor cabinet, discharge each capacitor to ground using a wire with a cross-sectional area of 10mm² or more. After visual inspection, ensure the casing is in good condition with no oil leakage. If the capacitor casing swells, handle it promptly by replacing the discharge device, the wiring screws of the control circuit, and the grounding device. After closing the circuit, adjust the indicator section and the automatic compensation section.
4: Maintenance of circuit breakers in power and control cabinets: First, disconnect all loads and then manually withdraw the circuit breaker using the handle. Re-tighten the wiring screws and check if the spring force of the blade is within specification. Inspect for any cracks or damage in the arc quenching grid. Manually adjust the mechanical interlock to ensure proper opening and closing, check for good contact between the contacts, and if necessary, file the contact surface. Inspect the internal springs, washers, and screws for looseness, deformation, or detachment.
Transformer cabinet maintenance:
1: Prior to operation, follow these steps: disconnect the load on the low-voltage side one by one, disconnect the circuit breaker on the high-voltage side, close the grounding switch, and securely lock the high-voltage switchgear. Place a "Do Not Close, Personnel Working" sign on the switchgear handle. Then, use a 10mm2 or thicker wire to short-circuit the busbars and hang a grounding wire, tightening the busbar screws.
2: Maintenance Operation Steps: Clean the busbar contact area thoroughly and apply electrical composite grease. Secure it with new spring washers and screws. Check for any abnormalities in the insulators and spacing connections between busbars. Verify the reliability of the connections at the secondary winding terminals of the current, voltage, and transformer.
3: Pre-power-on Inspection and Testing: Remove all grounding wires and jumper cables, check for any tools left at the work site, confirm there are no issues, close the isolating switch, disconnect the high-voltage side grounding switch, close the high-voltage side circuit breaker of the operating transformer, remove the signage, power on the transformer, then close the low-voltage side circuit breaker of the receiving cabinet, power on the busbar, and finally close the relevant interconnection cabinets and each branch's automatic air switch.
Cautionary Notes:
1: A designated person must supervise during the maintenance process.
2: Power must be tested before work.
3: The maintenance personnel should be familiar with and operate the electrical mechanical interlock system of the entire distribution cabinet.
4: During maintenance, be sure to identify which lines are dual-powered.
When inspecting busbars, ensure that the residual charge in the circuit is fully discharged.
Inspection Process
The inspection process for low-voltage distribution cabinets is divided into two parts:
Firstly, it's the inspection of the structural part, specifically the inspection of the box dimensions. For standard cabinets, a random inspection is sufficient.
Secondly, electrical inspection is required. Firstly, according to the technical drawings, check the component models, verify the torque of the connection points, and make markings (this task is quite labor-intensive and requires a thorough check). At the same time, pay attention to the creepage distance and the inter-phase distance to ensure they meet the standards, and whether the wiring complies with the company's process requirements. Then, check if the main circuit and control circuit are correct, using a multimeter to measure the lines. Next, perform an electrical function test to see if it meets the drawing requirements. Whether it passes or fails, a test report must be issued. The qualified items are labeled and shipped, and the不合格 items are returned for correction.
Cabling
One, Location: To ensure the normal and safe operation of low-voltage distribution cabinets, the location of the low-voltage distribution room should be close to the load center. The placement area should be free of dust and corrosive substances; otherwise, they should be cleaned promptly. For safety reasons, the environment should be relatively dry, and the placement should minimize vibration.
2. Distribution Equipment Arrangement: Distribution equipment in low-voltage distribution rooms must be arranged with safety, reliability, suitability, and economy in mind, and should also be easy to install, operate, transport, maintain, test, and monitor. There must be adequate spacing and exit points for the doorways of the high and low-voltage electrical equipment rooms and the arranged rows of distribution cabinets within the same room. Necessary safety measures should be taken when arranging distribution equipment, such as shielding or placing live conductors with hazardous potentials out of reach. If it's difficult to use shields and outer covers, protective barriers can be used instead.
III. The layout of the distribution lines should comply with the following conditions: meet the environmental characteristics of the placement location, match the characteristics of the building, consider the moderate distance between people and the lines, account for mechanical and electrical stresses that may occur due to short circuits, and consider other stresses the wiring may face during installation and use, as well as the weight of the wires.
Four: Factors Affecting the Layout of Distribution Lines: Preventing external heat from affecting use, preventing water entry from affecting use, preventing external mechanical damage from affecting use, preventing dust accumulation on wiring from affecting use, and preventing strong radiation from affecting use.
