Share: Construction skills of integrated wiring system

In the process of implementing the integrated wiring project, the placement of cables requires certain skills and must not be sloppy, otherwise the cables will have to be repaired later.

***, Cables suspended in the air: First we must consider the sag and pressure of the cables. After testing, we will decide which bundling method to use, and then solve the problem of whether the cables are directly exposed to sunlight.

Second, cables laid on the exterior walls: For cables laid on the exterior walls, the early stages will take into consideration issues such as wind and rain, but the main thing to solve is to avoid direct sunlight on the wall and human damage.

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Third, in pipes (plastic or metal pipes): the temperature, humidity, thermal conductivity, etc. in pipes of different materials are different, so pay attention to the damage of plastic pipes and the thermal conductivity of metal pipes.

Fourth, lay under the eaves: As long as the cable is not directly exposed to sunlight or ultra-high temperature, standard LAN cable can be used, and it is recommended to use pipes.

Fifth, laying directly in underground cable trenches: This environment has the smallest control range, and the cable trench installation must be regularly checked for dryness or humidity.

Sixth, underground pipeline: To facilitate future upgrades, cable replacement and isolation from surface pressure and surrounding environment, auxiliary pipelines are isolated. Auxiliary pipelines are a better method. But don't expect the pipeline to remain dry forever, which will affect the choice of cable type.

***Partly mark the cables, saving time and effort

1. Problem

Cables that are connected to workstations are not labeled or poorly labeled, which can lead to increased labor costs during and after the installation process. For example, improper labeling means that tradesmen must use a tone generator and induction pole to identify the cables after they are pulled. On a recent job, more than 1,000 cables were installed, and a project evaluation showed that each workstation took about an hour to complete. Proper labeling would have saved nearly 45 minutes of installation time per jack.

2. Solution

Using a widely used marking system before installation simplifies the task of identifying cables in case of doubt. By dividing the building into sections and assigning codes to each section, the tradesman can identify each cable, so tone generators and induction wands are not needed. Also, if the tradesman uses a logical marking system, it is very easy to correct or improve the drawings after construction when the end user remodels the facility.

3. Procedure

• Divide the installation into sections, giving each floor, orientation, room and socket a unique identifier, and in the case of a university, each building as well.
• All workstations and all equipment rooms and equipment boxes, such as connection blocks and face plates, must be reflected on the blueprint. These tasks must be completed before installation.
• Use labels that can be made on the spot to mark the wiring. Permanent or printer-made labels that can be written on will do.
• Finish the wiring as per the blueprint.
• After tying the cable, re-mark the cable within 6 inches of the knot. Use flags instead of wrapping the markers around the cable as you would when routing the cable. This will make it easier to tell at a glance.
• To improve the blueprint, mark changes and modifications in the wiring connections.

Part 2 Color coding speeds up cable identification

1. Problem

Cable identification is a nightmare for maintenance. Wire number tags, rope tags, and marking tapes dry out and eventually fall off. Number tags can be used, but they are difficult to locate because the tag is always facing the other way and close to the knot. Making a sound above the cable can sometimes help locate it, but it doesn't work in a noisy electrical environment. Therefore, maintenance departments often prefer to re-pull the wires rather than locate the cables.

Custom label manufacturers have good products, but they are expensive and once they fall off they don't stick so you never have enough labels when you need them.

2. Solution

Color-coded labels can solve this problem. Color-coded labels make it easier to locate from a distance. Such labels are inexpensive, and electricians generally have the basic colors on hand.

Using two of the 10 basic colors gives you 100 combinations (10*10); using three colors gives you 1,000 combinations (10*10*10)? Another benefit is that you can use different colors to represent different functions and departments. For example, the first color on the line (closest to the end) represents the function, the second represents the floor, the third represents the department, and the rest represent the wire identification.

For example, the first position has blue for voice and red for data. The second position has ten colors representing the 10 bits that distinguish the floors of a building. The third and fourth positions are obvious, but consider the wire colors when designing a color-coding system.

3. Procedure

• Design the color-coding system to be used and include it in the original data or expanded section of the file about the cable.
• Using a box to store identification tapes is convenient and clean.
• You can also cut a section and stick it on the vinyl sheet protector for easy carrying. The vinyl sheet can be easily placed in a notepad or tool box.
• Cut a length of marking tape and wrap it around the cable. Make sure it is at least two strips long.
• If the cable is in a location susceptible to physical or chemical corrosion, cover the tape with a transparent red sleeve before terminating or connecting.

Be careful not to put color markings close to the edge of the cable in case you have to cut it and re-end the wiring.

Part 3: Cable management before cable pulling

1. Problem

When pulling cables vertically or along a wall, it saves time and effort to pull as many cables as possible at the same time. However, a large number of cable bundles will get tangled in the conduit, get caught or coupled together at bends. Untangling or snagging can damage or even break the cables, especially the thin No. 5 cables.

2. Solution

To prevent this from happening when pulling the cables, it is important to carefully prepare the heads of the cable bundles. Shake the cables to knock them into a streamlined configuration, lubricate the heads, and carefully insert the cables into the conduit or pipe to prevent snagging and tangling.

3. Procedure

• Plan the number and type of wires you will be pulling together. Do you want to pack them tightly? For example, recently we pulled a coaxial line and three twisted-pair cables in a half-foot electrical metal tube, which is what packing tightly means.
• Arrange the spools and boxes so that the individual cables fit into the planned configuration. Choose a cable to use as the header. (If pulling several different types of cables at once, the most solid one is the best choice.)
• Select two or three cables---because they will be in the same working environment--and place them about an inch from the head. Wrap the head and the first group of wires in a spiral with an electrical loop, wrapping it tightly to protect the cables below.
• Arrange the second group of two or three cables about 6 feet behind the first group and wrap them with electrical loops. Where possible, place the cables in the depressions of the cable bundle so that they are as streamlined as possible. There should be no depressions when hanging during the pulling process.
• Do this until you have completed your plan. The number will depend on whether you are doing it by hand or with a crank, the gauge, length and routing of the cables, and how many work areas you are servicing. It is not impractical to run 10 to 15 cables at a time.
• Attach the head to the pull line with a slipknot, or to a mechanical snake. If appropriate, use lubricant while routing the wire. Make sure the lubricant is specifically for the tapered wire head, as this part is most susceptible to friction during routing.
• One installer goes to one end of the wiring work area and pulls the wires by hand or with a crank. The second person gently inserts the cable bundle into the pipe, conduit or switch, making sure there are no kinks, snags, or other damage to the cable. The two installers should be able to communicate, either by voice or radio.
• Once the cable bundle is pulled out at the other end, remove the guy wire or mechanical snake and knock the configuration off. Cut off a foot of the head as this part is likely corroded or damaged in the guy wire.

Part 4: Link distance measurement

1. Problem

In high-speed local networks, Category 5 cable links must be tested before use. The draft Electronic Industries Association/Telecommunications Industries Association 586A standard for commercial building cabling specifies a minimum horizontal cable link distance of 100 meters. To demonstrate compliance with the standard and reduce specific regulations, the handheld tester specifies the length of the link based on the nominal propagation rate of the Category 5 cable link to be tested.

Since the chain is mainly horizontal cables, this requirement is appropriate in most cases; however, there are some special cases, such as color plates, cross-links or cable positions that may change the propagation rate. When this happens, the measured length is inaccurate and the chain length is not standard.

2. Solution

Using a horizontal cable product with a continuous footer simplifies the task of rechecking the bond length. To obtain a secondary value for the chain length, add the horizontal cable length and the estimated length of all color plates and jumper wires used for the junction.

3. Procedure

Record the length in the package

• When installing, assign numbers and record the continuous footer of horizontal cables.
• After the chain is finished and the final junction is completed, add the horizontal cable length and the estimated length of the color plate and jumper wire to get the total horizontal cable chain length.

Handheld tester for measuring length

(1) Establish the appropriate nominal propagation velocity based on whether the cable is adequate (refer to the "Nominal Propagation Velocity" table).

• The nominal propagation rate is determined primarily by the insulation material used. Most manufacturers use polyethylene for unfilled Category 5 cable and fluorinated propylene for filled cable.
• Color plates are generally made of acrylic insulation and have a nominal propagation velocity close to that of a non-inflated No. 5 cable, slightly less - 68 to 69. The nominal propagation velocity of the jumper depends on the cable location.

(2) Use a short color bridge (usually provided by the manufacturer) to connect the tester to the chain. If the horizontal cable length is not significantly longer than the total length of the jumper/color bridge on the chain (2:1 or greater ratio), it is recommended that the tester be connected directly to the horizontal cable.

(3) Perform a self-test and compare the measured length with the recorded length. The two lengths should be within approximately 10 feet of each other.

Resolution of the difference between the two readings

• Re-determine the correct nominal propagation rate for the test, and re-test if the measurement is missing.
• Measure from the other end to determine the length. If the second end is closer to the recorded value, the connection point at the jack may be bad and the reading is inaccurate.