Requirements for the specifications of power cables during air conditioner installation

This post was last edited by hjztbwg on 2016-3-7 at 14:39. I. Pipe processing: (1) Pipe cutting; (2) Flaring. Special tools should be used. When expanding the pipe end, first smooth out the pipe opening, place the pipe into the clamping slots of the pipe expander, secure the copper pipe, and then slowly turn the pressing screw to apply gradual force. Generally, turn it 3/4 of a turn forward and then 1/4 of a turn backward, repeating this process until the pipe end is expanded to fit against the bevel surface of the fixture. When the active tip cannot rotate, remove the tube from the fixture. When connecting the piping of split-air conditioners to the compressor valves, a flared connection is generally used; therefore, the flared end must be round and smooth, without any eccentricity or burrs. (3) Straightening the mouth: When using a tube expander to straighten the mouth, replace the expander with the movable ejector pin for straightening, and then proceed as per the method for straightening flared mouths. The pipe should be annealed before flaring, and flaring should be carried out after natural cooling. The flare joint is used for socket welding connections of the same pipe diameter, that is, by the flare insertion method. The length of the flared portion must not be less than the diameter of the insertion tube. For example, if the outer diameter d of the insertion tube is 6 mm, the flaring length should be greater than 6 mm. The diameter of the pipe flare should not be too large, otherwise fractures and leaks may occur due to the excessively thin wall thickness and low strength at the flare area. For pipes with a diameter of 6 mm or less, the maximum flared diameter should generally be about 0.5 mm larger than the pipe’s own diameter ； If the pipe diameter is greater than 8 mm, it can be increased slightly. (4) Bending pipes: When copper pipes need to be bent, a pipe bender can be used. The tubes bent using a pipe bender have a smooth and even surface, without any wrinkling or flattening. In the installation of air conditioners, where certain pipe sections cannot be bent using tools and must be bent by hand, a screwdriver handle or some other cylindrical object should be placed at the point of bending; then the pipe should be bent slowly to prevent it from becoming dented or broken. Additionally, bent pipes should first be annealed using gas welding to soften them, making them easier to work with. (5) Welding at pipe connections: The sealing performance of an air conditioner’s refrigeration system is subject to very strict requirements; therefore, when welding pipes, it is essential to ensure high-quality welds and to follow the welding procedures strictly. The connection pipes in air-conditioning systems are all made of red copper, and red copper welding rods are generally used as solder at the pipe connection points. Welding at the pipe connection points is carried out according to the following steps. 1) Fill with nitrogen gas. Filling the copper tube with nitrogen before welding ensures that its inner wall remains smooth and clean, free of oxide layers, thereby effectively preventing the occurrence of \"dirty blockages\". 2) The joint should be polished before welding to remove oil films, paint films, and oxide layers from the welding area. During welding, the insertion depth of the two tubes should not be less than the diameter of the inserted tube, and the gap between the two tubes should be kept between 0.07 and 0.25 mm. This allows the solder to penetrate evenly into the gap without causing blockages in the tubes. To prevent solder from flowing into the tube through the gap, the weld joint must be in a horizontal position during welding; it is best to have the joint facing downward, and under no circumstances should the joint be welded with it facing upward, especially when welding capillaries. Special attention must be paid to this point. 3) Control the welding temperature properly. A neutral flame should be used during welding, with the center of the flame (i.e., the inner flame) being transparent being ideal. The flame should be directed at the end of the sleeve, not at the insertion tube. To avoid an excessive heating area, the welding flame should be at an angle of 60°–80° to the copper tube. When heating, the solder should not be heated directly; instead, it should be melted by the parts that are heated to a red temperature. Once the entire area around the joint is filled with solder, the welding torch should be removed promptly. If heating continues, the melted solder will drip from the joint or solidify at the bottom of the welded parts into teardrop-shaped solder beads. This not only leads to waste of solder but, more seriously, may affect the welding quality. 4) After the pipeline welding is completed, the weld area must be cleaned thoroughly; no residual oxides, slag, or similar substances should remain. To determine whether the weld is of satisfactory quality and free from blockages or leaks, it is necessary to use ammonia or a refrigerant to fill the pipe and conduct an inspection. II. Pipe Connection: The methods for connecting the indoor and outdoor pipes of split-air conditioners include flared connection, nut connection, quick-connect fitting connection, etc. (1) Flared connection: The flared connection is the most commonly used method of connection. The method of flaring both ends of the indoor/outdoor connecting pipes into bell-mouth shapes, thereby directly connecting the indoor unit’s pipe fittings to the outdoor unit’s valves, is known as bell-mouth flaring connection, or simply flared connection. When connecting, apply refrigerant oil to the fittings and flanges, then bend the piping to the appropriate position for connection. When connecting, be sure to align the pipe ends properly; first tighten the nut by hand, and then secure it with a wrench. (2) Nut connection: The nut connection is a method in which two copper pipes are joined together using nuts and double-ended connectors; it is simple to operate, but its sealing performance is poor, so it should be used only after leak testing shows no defects. (3) Quick connector connection 1) Quick one-time connector connection: The quick one-time connector is also known as a tool diaphragm connector. One end of the body has a cutting tool, while the other end is a thin metal sheet that can be used only once. 2) Multiple spring-type joint connections: Multiple spring-type joints are also known as detachable self-sealing joints. It takes the form of a spring diaphragm; it pushes open the pipeline diaphragm to establish connection when assembled, and it seals automatically when disassembled. During installation, it is essential to align the two bodies concentrically, then use two wrenches – one to hold firm and the other to turn – until it is tightened. III. Wire Connection: When connecting the wires, ensure that the colors of the terminals match. It is best to wire them according to the colors specified in the circuit diagram to avoid confusion. For some units, the terminal connections are made by matching A with A, B with B, and C with C; the connecting wires must be secured using clamps. For future maintenance purposes, the wires should be left slightly longer than necessary. After connection, they must be carefully inspected; if needed, verify them using a multimeter. Under no circumstances should the air conditioner be operated if there is any uncertainty. 1) Terminal block connection. During installation, follow the electrical wiring diagram, identify the terminal numbers and wire colors, and connect the wires to the terminal block correctly. When making the connection, the length of the wire inserted into the terminal block should be around 7 mm. When using connection rings, special washers should be used, and the screws provided with the device should be employed to secure the connection firmly. 2) Connection of single-strand wires: The connection of single-strand wires is usually done using a flat joint method, which includes self-wrapping and tying with binding wire. The connection is tight and reliable. 3) When connecting an air conditioner with an extended cable, it is generally necessary to use a cable of the full length to connect the unit. However, sometimes due to the relatively long distance between the indoor and outdoor units, the length of the original wiring is insufficient, necessitating the extension of the connecting wires. 4) Connection of multiple parallel single-strand wires. The branching connection method for multiple parallel single-strand wires is the same as that for a single-strand wire, but the contacts used for each branch must be spaced 30 mm apart. After connecting multiple single-strand wires, they should remain parallel and not twist around each other. 5) Wrap the wire joint: Wrap the wire joint with insulating tape. Common insulating tapes include rubber tape, yellow paraffin cloth tape, and black adhesive tape. When wrapping, first wrap a certain length around the insulating layer, and then tightly wrap the exposed portion. The wire connections also need to be wrapped with waterproof tape to prevent moisture from seeping in, which could lead to insulation failure and accidents. IV. Using a core drill to drill holes in the wall: When installing split-air conditioners, it is often necessary to drill holes in the exterior walls of the building, and core drill bits are generally used for this purpose. Core drills can be divided into rotary and vibratory core drills, as well as hammer-type core drills. Wall holes created using core drills have a neat and attractive appearance; they do not damage the interior walls, and the work can be carried out quickly. (1) Rotary and vibratory core drills. Its structure is shown in Figure 2.9. The specific assembly method for core drills is as follows. http://bbs.eszhileng.com/data/attachment/forum/201405/02/212724kvmu4r7b74ubcetm.png http://bbs.eszhileng.com/data/attachment/forum/201405/02/212733gezmrmbpeqgppymt.png http://bbs.eszhileng.com/data/attachment/forum/201405/02/212739yzemv3d7xqq8s376.png http://bbs.eszhileng.com/data/attachment/forum/201405/02/212746hb93ion2w2zgrs4s.png 1) Screw the handle in from behind the fixing plate, and assemble it with the ring and the moving plate to form an expansion connector, as shown in Figure 2.10. 2) Install the expansion connector into the housing and tighten it with two special wrenches, as shown in Figure 2.11. 3) Insert the center drill bit into the recess inside the handle, and use a hex wrench to tighten the fixing screw in order to secure the center drill bit, as shown in Figure 2.12. 4) Insert the shank into the drill chuck of the impact drill, and tighten the core drill bit using the chuck key. Once the core drill bit is assembled, hole-drilling can be carried out on the wall where holes are to be made. (2) Core drill bits for hammer drilling. The specific assembly method for core drill bits is as follows. 1) Screw the handle in from the back of the housing. 2) Insert the center pin into the guide plate. 3) Insert the assembled center pin and guide plate into the housing, and align the recess at the end of the guide plate with the protrusion on the housing. Insert the shank into the chuck of the rotary hammer (hammer drill) and secure it firmly in the retainer. Once the core drill bit for hammer drilling has been assembled, drilling can be carried out on the wall where holes are to be made. The specific steps are as follows: first, use a guide wrench and a center pin to drill guide ring holes in the wall. After the guide ring hole is drilled. Remove the guide plate and center pin. Then drill through the wall holes.