As China's rapid economic development and modernization, electricity load increases, Busway instead of cable has become a trend. As in many projects in selected low-quality products, but users, supervision, quality supervision station, electric power and other departments on the quality of not fully understanding Busway, is difficult to achieve strict checks to many engineering planted a safety hazard. Some projects even so there was a serious fire. In order to prevent shoddy products used in the project, this article describes the quality of identification and check Busway method for your reference.
Busway ensure the quality of the main technical:
A. Busway "temperature rise", make sure busbar current carrying capacity;
B. Busway "protection code", ensure busway dustproof and waterproof capability;
C. Busway "short-time withstand current", ensure Busway dynamic and thermal stability;
D. Busway "PE line structure", make sure busbar fault current does not endanger the personal safety of electrical equipment;
E. Busway "conductor material", make sure busbar conductor resistivity, conductivity standard requirements.
Busway quality control divided into the following three phases:
Phase I: ordering identification;
Phase II: arrival inspection;
Phase III: Installation and acceptance.
1.1 Review 3C certificate, type test reports, the temperature rise test reports, public security and fire resistance test reports.
1.1.1 3C Credentials: busbar rated short-time withstand current Icw (kA) and IP protection class meets the technical requirements of the tender. To prevent certificate forgery, can query the China Quality Certification Center website (http://www.cqc.com.cn).
1.1.2 3C Type test report: review of PE protective case doubles as a line or a separate PE conductor PE cable, conductor size and warm appreciation.
1.1.3 Temperature rise test report: Temperature rise test report is to identify the 3C certification specifications of the products covered by the current temperature rise and conductor size. Because 3C certification covering current specification more current specification is overwritten temperature rise test not done, some manufacturers free to write less covering current conductor size, causing some current specifications covering the current carrying capacity is insufficient. Therefore, the need to review the current specification is covered conductor specifications. If the current specification is covered current density per square millimeter, the test current specifications equivalent to a current density, it can not cover the current specifications temperature inspection report; overwritten if the current density is greater than the current specifications of the test current, must check each current specifications temperature rise report (including the shell structure of photographs, conductor size, temperature rise and test current, etc.).
1.1.4 Fire busbar fire resistance test report examines: key fire busbar fire resistance. Because in addition to ordinary refractory Busway Busway and test the various technical parameters, the important thing is to ask Busway fire should keep the integrity of the supply line, the need to maintain fire-fighting equipment, emergency lighting, back lighting, power generators and other main Route of normal power supply.
Complete line of test performance test is divided into two projects:
A. Fire, busbar is not caused by fire due to short circuit, resulting in not normal power supply. The time required to inspect fire and fire temperature.
B. In the fire sprinkler fire works when the bus is not due to water and fire-resistant insulation caused a short circuit, not the normal power supply, therefore, to examine spray test reports.
Note: All reports should be complete pages, meanwhile, should be covered with laboratory Jifeng, talent is the full report. For the authenticity of the report, inspection report Notice the amount of phone numbers are consistent with, and can call or letter from the advisory report to the authenticity.
1.2 Sample review: key products, production processes, bus connector's IP protection class, temperature rise and PE busbar plug the interface line stability and effectiveness.
1.2.1 Product Process; mainly to check the appearance of the machining process, the surface treatment process and busbar assembly precision. Compact Busway mainly to see the dense compactness, the more compact the better.
1.2.2 Busway and Busway header with the IP protection class: Protection class is the most important technology, engineering bus connector is the site of the highest accident rates, joints fever or moisture, or water caused by short bus more than the number of accidents, with particular attention to the IP protection class connectors. Because GB 7251.2-2006 is the international standard IEC 60439.2-2000 literal translation of the standard on the protection of the trials did not mention busbar busbar joints to do with protection class test, China is implementing the 3C certification standards developed by the implementation of rules, so look at the sample bus with bus connector parts of the seal case.
1.2.3 Plug-in connection dense structure: Busway is divided into intensive and air type, cooling capability gap. There are many manufacturers intensive body structure, and plug the interface air-type structure, causing plug the interface temperature higher than the bulk 20 ~ 30 ℃, causing severe current carrying capacity of plug-in connection drop and tucks, the safety plug box accidents.
1.2.4 PE line stability and effectiveness: busway PE line is to protect the lifeline. Standards, PE line is not less than a certain ratio of the phase line, mainly on account of the event Busway leakage or short circuit to ground, make sure that the current accident evacuation to ensure that bus enclosure without compromising the safety of persons and electrical equipment, protect effect.
A. When using an independent line structure PE, PE line section, insert the claw section, busbar PE wire plug terminal section shall comply with standards.
B. As PE line using shell structure, PE line section, insert the claw section, busbar PE wire plug terminal section shall comply with standards equivalent value, PE wire connection at the head of the connection is stable, effective, and to ensure that connecting conductor cross-sectional area.
C. During routine maintenance to ensure that the PE line is not to be cut off or reduce the flow area.
1.2.5 Look at the interface plug shell PE line is valid, plug terminal and a copper-aluminum welding transitional housing, plug plug claw should be plugged into the box on copper, copper and aluminum surfaces should not be directly accessible.
1.2.6 Fire resistance tests. Provide two units are connected busbar good fire detection fire resistance, bus ends connected to the introduction of the power supply and insurance, the other end connected to lights, using a torch or gas stove, facing the junction burning, fire temperature 950 ~ 1000 ℃, according to the provisions ordering required fire resistance time of burning. The lamp is off, indicating that the product failed.
2.1 Shell, structure, should 3C temperature rise test reports and description of the report unanimously.
2.2 Conductor size, conductor with a vernier caliper to measure the thickness and width of whether 3C temperature rise test reports and description of the report unanimously.
2.3 Using loop resistance tester test specifications and busbar conductor resistivity, clamped at both ends Busway head bare copper resistance measurement, measurement of conductor length, width, thickness, resistivity can be calculated, which detection methods to meet the control copper clad aluminum, copper welding head ends of the intermediate aluminum row, two big middle small and conductor materials and other identification needs. GB5585-2005 standard, copper conductivity ≥ 97%, resistivity ≤ 0.01777Ω·mm2/m, aluminum row conductivity ≥ 59%, resistivity ≤ 0.029Ω·mm2/m.
3.1 Current carrying capacity tests using low voltage high current generating means for carrying on the busbar test (test current busbar rated current), to the temperature variation is less than 1K per hour stop. Temperature rise is a plug-in connection or connection conductor maximum temperature minus the difference between the ambient temperature shall meet the user requirements.
3.2 IP protection class according to GB4208 standard tests, including bus connector and elbow and the body should meet the requirements set IP or user tender requirements. IP51 above, should be tested for insulation resistance test.
3.3 Using 1000V megger insulation resistance measurement Busway, a single bus segment should be greater than 20MΩ, length should be greater than 1MΩ.