The new acceptance specifications greatly enhance engineering requirements

After three years of long wait, the acceptance specification for Integrated Wiring of version 2007 was finally promulgated. After seeing the new specification and comparing it with the specification of version 2000, the general impression is that the acceptance requirements of Integrated Wiring have been significantly improved based on the past. This is of great significance for further improving the quality of Integrated Wiring System Engineering.

As we all know, the Integrated Wiring System performs the foundation function in the intelligent building project. It is almost invisible and cannot be touched. It can not be absent in the intelligent building, its quality directly determines the quality of smart buildings. Even in the eyes of computer network administrators, once a fault occurs in the Integrated Wiring System, the maintenance difficulty will be greatly improved, because it can only be repaired on site, it is impossible to "Never get new" like a network device ".

In the new acceptance specification, the acceptance requirements for the following aspects are mainly strengthened:

1) Promote lightning protection to mandatory provisions

The new specification adds a surge protection requirement for outdoor copper cables, which requires that all copper cables must be protected when entering the building. This point is written into the Integrated Wiring Specification and promoted to the mandatory terms, which helps to protect the safety of life and equipment and greatly reduce the damage caused by lightning strikes.

2) added requirements for the cabling

In the design specification, it is clear that the entrance is listed as one of the seven major parts, which is consistent with the horizontal distribution subsystem, vertical trunk subsystem, and complex trunk subsystem. In the acceptance specification, clear requirements are put forward for the pipeline, cable, and room to be introduced.

3) imported equipment and materials shall have a certificate of ownership and a commercial inspection certificate

A considerable number of integrated wiring products come from abroad, which plays a major role in improving the level of Integrated Wiring in China. However, in the past, there were no clear requirements for imported products, making it difficult to grasp the quality of products used in the project. This time, in the inspection of equipment, the requirements for imported products are put forward separately. The ultimate goal is to control the quality of imported products.

4) requirements for regular measurement of testing instruments and tools

According to the characteristics of the instrument and meter, most of the instrument and meter have the drift time), that is, due to the passage of time, the error of the instrument and meter has increased. Therefore, all Metering Instruments require regular metering to ensure that the test data is accurate and valid. In the performance tester of the Integrated Wiring System, measurement is usually required once a year.

In the new specification, the requirements for Regular metering are clearly stated, which meets the relevant national metering standards and helps improve the reliability of the test results.

5) "separate laying of Integrated cabling cables" is required"

The Integrated Wiring System is a part of the Weak Current System of buildings. During the pipeline design of construction projects, it is generally considered as a whole with the subsystems of other weak current systems. When the space is limited, most of them are laid in a hybrid manner. Therefore, in the cable tray of the Integrated Wiring System, the cables of other weak current subsystems, including the ground wires, are sometimes seen ).

In the new specification, it is clearly required that the integrated cabling cable be laid separately, and that the cable spacing with the other subsystems of the weak current system should comply with the design requirements and can be added with a metal partition ). This will help improve the engineering quality and long-term reliability of the Integrated Wiring System.

By the way, for some cabling projects that use plastic separator groove for the sake of appearance, if the power cords and twisted pair wires are laid separately in the upper and lower troughs, it may violate the acceptance specifications, as a result, the power cord applies electromagnetic interference to the twisted pair, which may affect the transmission rate of the twisted pair and the error rate of the network system.

6) puts forward the requirements for the Integrated Wiring System in the classified project

With the popularization of integrated wiring systems and the increasing importance of security and confidentiality, integrated wiring systems have been widely used in projects with security and confidentiality requirements. Therefore, in the new specification, the requirements for integrated cabling systems in classified projects are put forward, including the Gap Between cables and other cables and separate laying requirements.

According to the relevant national standards, cables for classified projects explicitly require shielded twisted pair wires or optical cables. If unshielded twisted pair wires are used, the distance between cables must be at least 1 MB.

7) both the 568A and 568B cabling modes can be used.

In the acceptance specification of version 2000, The 568A connection mode is the primary requirement. The main reason is: when the Integrated Wiring System transmits 2-to-2 lines of telephone mainly refers to digital phones, such as rarely seen Call Center dedicated telephone switches and digital telephones, if the distribution frame used for end-to-end horizontal twisted pair is a 110-type distribution frame, you can use one pair of duck tongue jumpers in the 568A connection mode, the 568B connection method uses two one-to-one duck tongue jumper or one four-to-four duck tongue jumper. From the perspective of cost, one two-to-one duck tongue jumper is the cheapest. Therefore, there are two Connection Methods in TIA/EIA 568-1990.

Today, two pairs of digital phones are rarely used in daily work, while most of the horizontal distribution subsystems use RJ45 patch cord distribution frames, instead of using the 110-type cabling rack that is inconvenient to maintain. In this way, the effect of the two connection methods is exactly the same, and naturally the connection method does not need to be optimized.

8) the performance test should not only adopt the typical value, but also conform to the fitting curve.

In the past Integrated Wiring Specification, only the data provided to the tester is the data at a typical frequency point. In this way, a technical parameter is only a partition parameter.

In the current wiring test, a technical parameter such as NEXT usually needs to measure data of thousands of frequency points. The data of each frequency point meets the requirements, in order to pass the technical parameter. These data uses frequency as the abscissa to form a high and low curve. In the testing instrument, an ideal curve is used as the demarcation line to check whether the data is qualified.

In the new specification, the fitting curve formula identical to ISO 11801-2002 is used as the standard parameter for the acceptance of the Integrated Wiring System, the significance is that the current acceptance test should not only meet the requirements on several frequency points, but also be able to meet the requirements on the entire frequency segment.

When the system integrator needs to prove that his project complies with the national standard GB 50312-2007, it needs to use a performance tester supporting GB 50312-2007. I just don't know when the three major tester manufacturers will be able to provide testing instruments supporting GB 50312-2007? Allow the following external saying: You only need to modify the software in the tester.

9) puts forward the requirements for shielding layer connection of twisted pair wires.

It is not difficult to shield the shielded layer of twisted pair wires, but you need to master the necessary rules. This requirement has been put forward in the Specification, requiring effective end-to-end connection between the braided layer or metal foil and the consortium wire.

In the European Integrated cabling standard EN 50174.2-2001, it was previously required that the typical products of twisted pair wires with wire mesh braid layers be SF/UTP and S/FTP ), only the wire mesh must be grounded. F/UTP and U/FTP are typical aluminum foil twisted pair wires. the aluminum foil and the grounding wire must be grounded together.

10) propose the qualification criteria for project acceptance

In the current integrated wiring project, the project is often unable to achieve 100% of the performance, and the acceptance is usually used in the sampling method. In the new specification, a qualified criterion is proposed, that is, the method for determining that the acceptance pass rate reaches 99%. For the construction personnel, this method avoids absolute and idealized, and makes the acceptance test operable.

However, it is required in the specification that "if there is a fiber channel in the system that cannot be repaired during Optical Cable cabling detection, the system will be deemed as unqualified ". If all the data in the horizontal distribution subsystem uses optical fiber cabling, is this too high?

With the changing times, the specifications of the Integrated Wiring System have been constantly upgraded and improved. For example, the GB/T 50312-2000 is better than that of CECS 89-97, the 2007 standard after seven years should naturally be better than the 2000 standard, which is the requirement of the times and is also in line with the continuous progress of construction personnel.

Relatively speaking, the new acceptance specification draws a lot of valuable information from the domestic and foreign standards, so that the new specification can play a very practical guiding role in the implementation and acceptance of the wiring project in both depth and breadth.

1. New Integrated Wiring standard officially announced
2. Lan acceptance Specification