One-unit electrical: Steps and precautions for installing and wiring a distribution box cabinet

With the power grid, infrastructure, manufacturing investment and the development and implementation of the new energy industry, the importance of the power distribution cabinet is getting higher and higher for the enterprise.

For many companies, this is essential electrical equipment.

The power distribution cabinet is not something everyone knows about in our lives, but it is closely related to People's Daily electricity consumption.

Low-voltage switchgear equipment is used in manufacturing industries such as power stations, the energy industry, textiles and multi-storey buildings in the metallurgical industry.

It is used for transmission, scheduling and conversion of electric power engineering.

The more important the electrical equipment, the more clearly we understand its installation and wiring steps and precautions.

1. Install the PDC

1. Production and installation of bottom seat of distribution box

The bottom of the distribution box is usually made of steel, and its steel specifications are determined according to the size and weight of the distribution box.

Section steel is levelled and straightened before cutting.

2. Unpack the PDC

Before installing the PDC, you need to open the packing case to check the certificates and product manuals. Secondly, check whether the power distribution cabinet is in good condition, and then fill in the main inspection contents in the equipment unpacking inspection record.

3. Install the PDC

Install the power distribution box firmly on the base channel steel, tighten the cabinet with bolts, level the cabinet, align the bolts, and weld the cabinet to the base channel steel. The panel cabinet should use 6mm soft copper wire and grounding backbone necklace as protective grounding.

2. Install the hard bus

1. Fixing the bus bar on the support insulator

The low voltage bus is secured by low voltage porcelain bottles or plastic supports.

Before installing the bus, you must install the bus support frame and support insulators.

2. Busbar expansion joints

Expansion joints shall be installed on the bus bar according to the design regulations. If there is no provision, one should be installed at an interval of about 20m.

The expansion joints are made of copper or aluminum plates between 02 and 05mm thick.

3. Bus layout and painting

The sequence of bus layout should conform to the design regulations. If the design does not have clear requirements for bus layout, the following provisions can be referred to:

When the bus is vertically arranged, the arrangement of AC L1, L2 and L3 phases should be from top to bottom, and the positive electrode of the DC bus is at the top and the negative electrode is at the bottom;

When the bus bar is placed horizontally, the arrangement of AC L1, L2 and L3 phases should be arranged from the inside out, and the positive and negative terminals of the DC bus should be arranged from the inside out;

The AC bus bars arranged horizontally on the switchboard are divided into L1, L2 and L phases. L3 from the back of the panel to the surface of the panel;

(4) When the lead line is arranged, AC L1, L2 and L3 are arranged correspondingly from left to right, and DC positive and negative poles are arranged from left to right;

The distribution equipment of different voltage levels in the whole plant should be consistent with each other;

The uniform arrangement of the bus phase sequence is stipulated, which helps the safety of the operator.

Third, the installation and wiring of the circuit in the distribution cabinet

1. Draw and install voltage circuit wiring diagram in PGL1 low-voltage distribution cabinet

1 Voltage circuit wiring diagram drawn by conventional diagram method;

2. Numbering method of voltage circuit wiring diagram drawn relative to the diagram;

3 Press P

GL1 Low voltage distribution cabinet voltage circuit wiring diagram for installation and wiring.

2. Draw and install the wiring diagram of the current loop in the PGL1 low-voltage distribution cabinet

1. Current loop wiring diagram using conventional drawing method;

2. Current circuit wiring diagram drawn by relative numbering method;

3 Install cables based on the current loop wiring diagram of the PGL1 low-voltage PDC.

4. Prepare materials and documents for calibration and engineering acceptance of voltmeter and ammeter in advance

1. Calibration, operation and linkage test of voltmeter and ammeter.

2. Materials and documents prepared in advance for project acceptance:

1 Specific construction drawings that are part of the modified design concept;

2. Proof materials of the revised design concept; Technical documentation provided by the manufacturer, such as product manuals, test records, certificates of qualification and installation drawings;

4 Construction records of electrical equipment installation projects;

5 Adjust test records.

Five, check after installation

1. Check whether the installation quality of the electrical equipment, electrical components, and distribution cabinet meets the installation regulations and standards.

2. Check the cable connections according to the phase sequence of the UL1 yellow, VL2 green, and WL3 red switching power supplies.

3. Check whether the cables to each wiring terminal meet the installation standards, and tighten the screws.

4. Check whether any connection error or loss occurs based on the wiring diagram.

5. Check the quality of route installation.

6. Cable connections to the low-voltage PDC

1. When wiring cables, the low-voltage open power distribution cabinet cannot be placed near the copper sheet. When the entire vehicle wiring harness passes through the carbon steel plate hole, protective measures should be taken.

Each terminal must be connected to a maximum of two cables.

When selecting the vehicle's wiring harness, the fixed vehicle wiring harness should be arranged horizontally and vertically, and should be tied and fixed.

The binding interval shall not exceed 90mm, the fixed and constant interval of the horizontal vehicle wiring harness shall not exceed 300mm, and the fixed and constant interval of the two equipartition wiring harness shall not exceed 400mm...

2. The wiring harness of the low-voltage PDC is based on metal holes, doors, and corners. Please wrap the entire vehicle harness with tape.

The tape used for turning the door should be 2-3 layers, the length is about 60mm, and other positions should be set according to the situation.

Ensure that the maximum capacity of the tape on both sides of the hole is 22mm.

When the harness of the suspension system is not fixed and exceeds 300mmi, it should be fixed, and the electrical system should be constant. The distance between the harness of the entire vehicle and the induction electrical system bus, power cord plug or induction electrical bare wire exceeds the distance in Table 1. The specified interval.

3. For the low-voltage PDC, check whether the protective grounding components are securely connected and in good contact.

According to the secondary wiring diagram for building construction, whether the wiring is appropriate.

The wiring should be neat and unique, and the power cable sheath should be of high quality and not damaged.

Each crimping terminal can only be connected to one cable, and the number of cables must not exceed two. Two electrical wires can only be connected if the terminal or terminal's technical specialized program is designed to connect two cables.

4. The reactive load compensation control board installed in the low power distribution cabinet is selected as PHILIP

S Core technology uses reactive power loads as physical properties that can operate reliably in large pulse currents, non-positive flows, strong impacts, and other extreme grid natural environments. PHILIPS kernel, pseudo-random effect value sampling and intelligence

By lonely, high-precision, price-sensitive control: Intelligent long queue storage capacity function and automatic elimination of defective capacitor banks.

7. Precautions for installing a PDC:

1. If the PDC is installed in a vibration place, take anti-vibration measures.

2. The cabinet itself, the mechanical devices in the cabinet, and the prefabricated components must be securely connected. The main control box, relay protection cabinet and protection cabinet are not suitable for immediate welding with the base channel steel.

3. When installed separately or on the display, the flatness, flatness, bank roughness and the allowable error of the cabinet indirect joint should be installed according to the project construction regulations.

4. The junction box should be firmly installed and sealed, and the installation position should be easy to check;

5. The ground device of the cabinet must be secure.