1.2mm Carbon Steel Electrical 300 x 400 x 200 mm Enclosure Box IP66 Wall Mount

User Manual for Distribution Boxes

I. Basic Understanding of Distribution Boxes

II. Installation Precautions

1. Location Selection
   • It should be installed in a dry, well-ventilated place that is convenient for operation and maintenance, avoiding damp, water-prone, corrosive gas-containing, or dusty environments to prevent the electrical components inside the distribution box from being affected by moisture, corrosion, etc., which could impact normal use and service life.
   • It should be installed in a conspicuous and easily accessible location for personnel, while also preventing unauthorized access by irrelevant people. Generally, the installation height needs to comply with relevant safety specifications. For example, the bottom surface of a floor-standing distribution box should be raised a certain distance above the ground (usually 50 – 100 millimeters), and the center height of a wall-mounted distribution box from the ground should be about 1.5 meters.
2. Installation and Fixing
   • It must be firmly installed on the wall or a dedicated support structure using appropriate expansion bolts or other fasteners to ensure that it will not become loose or fall off under normal use or when subjected to certain external forces, thus ensuring the safety of use and the stability of line connections.
   • For outdoor distribution boxes, consideration should also be given to having certain protective measures against rain and sunlight. A rain shelter can be installed for protection to avoid rainwater directly entering the box and causing electrical faults.

III. Operation Precautions

1. Qualifications of Operators
   • Only qualified electricians who have received professional training, are familiar with the operation procedures of the distribution box, and possess relevant electrical safety knowledge can operate the distribution box. Unauthorized personnel are strictly prohibited from operating it at will to avoid electrical safety accidents such as electric shock and short circuits.
2. Preparations Before Operation
   • Before operating the switches and other components inside the distribution box, it is necessary to wear necessary personal protective equipment, such as insulating gloves and insulating shoes, to ensure personal safety.
   • Carefully check the appearance of the distribution box for any abnormalities, such as whether the box body is deformed or there is a burning smell. If any abnormal situation is found, the cause of the fault needs to be investigated first, and operation should not be carried out rashly.
   • Clearly define the purpose of the operation and know exactly which specific switches and buttons correspond to which lines and electrical equipment to avoid misoperation.
3. Switch Operation
   • When closing the switch, slowly push the switch handle to ensure good contact of the switch contacts. After the switch is closed in place, check whether the corresponding indicator light (if any) lights up normally to confirm that the line has been powered on normally.
   • When opening the switch, the operation should also be carried out smoothly without excessive force. After the operation, check whether the electrical equipment has stopped running. If necessary, use tools such as a test pen to check whether the line is indeed de-energized to ensure the safety of subsequent maintenance and other work.
   • For switches with interlocking devices, the operation must be carried out strictly in accordance with the interlocking requirements, and it is prohibited to forcibly break the interlocking for illegal operations.

IV. Daily Maintenance Precautions

1. Exterior Cleaning
   • Regularly (it is recommended to do it at least once a month) clean the exterior of the distribution box. Use a clean, dry cloth to wipe the dust on the surface of the box body to keep the box body clean, which is convenient for observing whether there are any abnormal changes in the appearance of the box body and is also beneficial for heat dissipation (which is important for some distribution boxes that rely on natural heat dissipation).
2. Internal Inspection
   • Arrange for professional electricians to open the door of the distribution box every quarter or half a year (the cycle can be adjusted appropriately according to the actual use environment and frequency) to inspect the internal electrical components. Check whether the contacts of each switch are burned, deformed, whether the connecting wires are loose or show signs of overheating and discoloration, and whether the fuse element is intact.
   • Check whether the readings of various instruments (such as voltmeters, ammeters, etc.) are normal and whether the pointers are flexible. If the instrument display is abnormal, it should be calibrated or replaced in a timely manner to ensure that it can accurately reflect the operating parameters of the line.
   • Organize the wiring inside the distribution box to avoid messy wires and prevent short-circuit faults caused by friction and squeezing between wires.
3. Grounding Inspection
   • Regularly check whether the grounding system of the distribution box is in good condition, whether the grounding connection is firm, and whether the grounding resistance meets the safety requirements (generally, the grounding resistance is required to be no more than 4 ohms). If there is a problem with the grounding, it may lead to the inability to effectively conduct current to the ground in case of leakage and other faults, bringing serious safety hazards.

V. Safety Warning Signs

1. Obvious safety warning signs should be posted on the box body of the distribution box, such as “Danger! Electric Shock Hazard”, “Do Not Close the Switch, People Are Working”, “Stop! High Voltage Danger” (if high-voltage parts are involved). The signs should be clear and conspicuous to remind operators and people around at all times to pay attention to safety.
2. For a distribution box that is undergoing maintenance or other operations and has been de-energized, a sign reading “Do Not Close the Switch, People Are Working” should be hung on the corresponding switch operating handle, and appropriate safety barriers should be set up to prevent others from closing the switch by mistake and sending power.

VI. Fault Handling

1. Common Faults and Their Manifestations
   • Short-circuit Fault: It is often manifested as the switch in the distribution box tripping, a distinct burning smell, and smoke from the line. Generally, it is caused by damaged wire insulation, internal short circuits of electrical components, etc.
   • Overload Fault: There may be frequent tripping of the switch, but there is no obvious burning smell or smoke in the distribution box. This is mostly due to the total power of electrical equipment exceeding the rated carrying capacity of the line or switch.
   • Leakage Fault: Some distribution boxes are equipped with leakage protection functions. When leakage occurs, the leakage protector will trip, and there may be a feeling of electric shock if a person touches the leaking part. The reason is usually that the insulation of electrical equipment is damaged or the line is affected by moisture, resulting in the enclosure being electrified.
2. Fault Handling Principles and Steps
   • Once a fault is found in the distribution box, unauthorized personnel should not handle it on their own. Professional electricians should be notified immediately to carry out repairs.
   • After the professional electricians arrive, first cut off the power of the previous level (under the premise of ensuring safety) to prevent the fault from expanding and to ensure the safety of the maintenance personnel.
   • Based on the manifestations of the fault, preliminarily judge the type of fault, and then use professional electrical testing tools (such as multimeters, megohmmeters, etc.) to check the relevant lines and electrical components one by one to find the root cause of the fault and carry out repairs. After the repair, a trial power-on operation should be carried out to confirm that the fault has been eliminated and the distribution box can operate normally before normal power supply can be restored.

VII. Emergency Situation Handling

1. In case of an electrical fire or other emergency situations, immediately cut off the main power supply of the distribution box (if it can be operated safely), and use appropriate fire extinguishing equipment (such as dry powder fire extinguishers. It is strictly prohibited to use water to extinguish electrical fires) to put out the fire. At the same time, quickly evacuate people around and call the fire alarm number.
2. If someone is electrocuted, do not directly pull the electrocuted person with your hands. Instead, turn off the relevant power switch of the distribution box as soon as possible or use an insulating object (such as a dry wooden stick, plastic rod, etc.) to separate the electrocuted person from the live body, and then immediately carry out first aid on the electrocuted person (such as performing cardiopulmonary resuscitation, etc., and call the emergency number in time to send the person to the hospital).