The Complete Guide for Insulator String

Now let’s explain the insulator string installation construction.

第1章 - 絕緣體串的類型

According to the different connection ways, there are four types of insulator string， single tension string, double tension string, single suspension string, double suspension string.

單張張力字符串

single suspension string

double suspension string

Chapter 2 – Components of insulator string

• Insulators and insulator sets

The single “I” composite insulator, long rod type, of sufficient mechanical capacity are used for the outer phases, and a “V” insulator set for the middle phase.

The minimum creepage distance is related to the highest system (phase to earth) voltage, USCD as perIEC 60815。

The insulator string is of sufficient length to provide the required electrical performance in regard to specific leakage paths and minimum required to withstand voltages. This is confirmed by tests on complete sets, as the insulator set fittings contribute to overall performance.

所有絕緣體集都提供了必要的電弧設備，以便保持其無線電和電視噪聲盡可能低。在標準實驗室條件下確保在1磅以下小於50 dB的噪聲水平。根據所提到的標準，這是通過測試證明的。

All insulator sets are designed to withstand the single-phase fault currents. Locking devices for the insulator units themselves and for an associated ball and socket fittings are of stainless steel and comply withIEC 60372。The design is such as to allow easy removal for replacing of insulator units or fittings without the necessity to remove the insulator set from the cross-arms. Locking devices are incapable of rotating when in position.

The double suspension insulator set is used for crossings of main roads, railways, navigable waterways and other overhead transmission lines. Double tension sets are used as standard sets on tension towers.

• 複合絕緣體單位

複合絕緣體

The insulator units consist of composite long-rod type insulator featuring a glass-fiber reinforcing epoxy rod core with high temperature vulcanized silicone rubber housing and clevis caps.

Design of Composite insulator units

絕緣體具有足夠的長度，以在一個單位中提供所需的電氣性能。兩個或更多單元的在線耦合是危險的。

芯具有具有高強度（纖維增強塑料棒）的軸向玻璃纖維增​​強的環氧樹脂棒。在杆和殼體之間形成的界麵將具有以防止脆性斷裂現象的質量，即需要高電強度和等效酸性抗性。因此，E-Cr玻璃纖維用於芯。

The core of the composite insulator is protected against environmental influences by silicone rubber housing. The thickness of the silicone rubber covering the rod is at least 3mm. The housing is perfectly (chemically) bonded to the core. The chemical bond between the core and the housing is stronger than the tear strength of the housing material.

Jingyoung has a proven record of using non destructive technique (N.D.T.) to check the quality of the core to the housing interface.

The silicon rubber can be directly molded onto the core. In order to achieve an excellent pollution performance and tracking performance (minimum class 1A 3.5 according toIEC 60587), the application of high temperature vulcanizing (HTV) silicon rubber filled with an appropriate amount of Aluminum trihydrate (ATH) is applied. The material is of blue/gray color and is resistant against the ultra-violet radiation being present in the solar spectrum at ground level. For the design of shed profiles,IEC 60815is applied.

The metal end fittings are made of forged steel andhot dip galvanizedaccording toISO 1461.The fittings are attached to the rod by a compression method process which does not damage the individual fibers of the rod in any way. Fittings configuration are defined by the actual need (e.g. ball and socket or clevis and tongue connection) and will comply with the standard requirements.

擬合和核心的住房是希爾的差距d permanently against the ingress of moisture. Sealing by compression only is not regarded to be permanently waterproof. Covering the cap, even partly, with housing material is unacceptable due to electrical reasons. Sealing of the interface by application of an elastomer with permanent elasticity is considered an acceptable solution. The material will adhere to the surface of the metal cap, as well as to the housing.

• Fittings for insulator strings

insulator fittings

The insulator units are assembled to insulator sets with appropriate fittings. The design of adjacent metal parts and mating surfaces are such as to prevent corrosion of the contact surfaces and to maintain good electrical contact under service conditions.

所有部分被設計成能抵抗機械loads during the lifetime as calculated for the insulator string sets and to avoid loosening in service due to vibrations or due to other reasons.

The insulator set fittings connection-to-tower withstand without Q degradation such a short-circuit current without exceeding a temperature of 400°C. All ferrous parts of the assemblies component elements and of the accessories for conductors are hot dip galvanized according to ISO 1461, with a coating of 610 g/m2(85 gm), except for bolts, nuts, and墊圈，最低395克/平方米（55克）將被接受。

Split pins of all clamps and fittings are of stainless steel.

Arcing rings

Arcing rings The arcing rings of the insulator sets must fulfill simultaneously the functions of arcing rings, corona shield, and potential distribution devices.

作為電弧裝置，保護環設計成在閃絡發生時保護絕緣體和導體。電弧配件由熱浸鍍鋅鋼製成，具有能夠承受短路電流的能力。電弧配件設計成使得在閃光燈的情況下，電弧將導致端部燃燒點。

在短路期間，它們可能達到不超過400°C的最終溫度。電弧保護的功能不得通過功率弧大大改變。

As corona shield devices, the guard rings are designed to ensure under fair weather, and under the specific site conditions, a corona-free insulator set line end as well as the specified insulator set radio noise performance.

As potential distribution devices, the guard rings are designed to ensure a uniform distribution of the potential along the insulator string.

保護環的設計考慮並同時優化所需的所有功能。

The rings are strong enough to support a weight of 90 kg without permanent deformation. The ring attachment is via bolted connections to the hardware assembly.

Chapter 3 – Rating and design of insulator string

design of insulator string

A minimum creepage distance of 25mm/kV applies to suspension and tension insulator strings throughout the length of the transmission line.

絕緣子和配件的設計是為了避免局部電暈形成和放電可能導致過多的無線電幹擾;所有絕緣子配件都使用帶有分裂引腳或“尼龍”或類似扭矩螺母的電暈自由螺母

Chapter 4 – Manufacture of insulator string

Suspension and tension insulators are of the long rod composite type and for the type of fittings, the contractor has to take prior approval from Engineer-In charge. The insulators are manufactured completely with a suitable corona ring and corona free nuts and split pins.

絕緣體是防穿刺型。這些絕緣體由芯玻璃纖維增​​強樹脂和不同塑料材料的脫落製成。它們具有輕質和高抗拉強度。它們可以安全地承受所有操作壓力，包括臭氧和紫外線輻射，絕緣體的配件將根據IEC 61109匹配。符合IEC 61109。絕緣體的所有部分都沒有任何可能損害絕緣體的機械或電性能的缺陷。

All materials, whether fully specified herein or not, are of first class quality and shall conform to the best modem practice and comply in all respects with these Specifications. The materials shall be free from folds, cracks, and other exterior and interior defects that can affect its strength, ductility, durability, or ability to function.

All materials will be inspected and tested in full to prove compliance with the requirements of these Specifications and to the satisfaction of the Employer.

The testing shall be carried out according to the relevant standards approved by the Customer.

Assembly is performed in such a way that the mechanical properties cannot be affected and to ensure that the insulating part is not subject to any mechanical stress due to pressure exerted by the bottom edge of the cap.

The free surface of insulating parts will be cleaned of impurities.

允許的公差將根據IEC 61109符合要求：

Each insulator can be marked with the following information:

Customers’ name or logo;

production year;

specified mechanical load;

identification code providing traceability.

Chapter 5 – Testing of insulator string

測試絕緣子和硬件

Tests of Insulators and insulator sets

• The insulator units and the insulator sets are subject to type, sample and routine tests according to:
  • IEC 61109 - 用於交流架空線的複合絕緣體，標稱電壓大於1000V，定義，測試方法和驗收標準。
  • IEC 60437- Radio Interference Test
  • IEC 60507- Pollution Test
  • IEC 60587-評估跟蹤和侵蝕抗性的測試方法
  • IEC 60591 – Sampling rules and acceptance criteria.
• Type, sample and routine tests will be performed according to applicable standards.
• Regarding composite insulators, the following sample tests will be carried out in addition to IEC 61109:
  • 96 H耐酸性的載荷杆，以評估指定的玻璃材料是否合適
  • 96 h tensile test (60% of UTL or 70% of SML as per IEC 61109) with the determination of UTL subsequently, in order to verify compliance with type test certificates
  • Tracking and erosion tests as per IEC 60587 applied for a specimen of housing material, in order to prove the housing material.

General Tests

所有組件的完整和完整的測試（設計測試，類型測試，采樣測試，日常測試將根據IEC 61109（最新版本）和客戶滿意。

Sample Tests

Jingyong will carry out the sample test in accordance with IEC 61109.

Jingyong ill keep the Engineer informed about the progress of Jingyoung of materials and works so that the witness, inspection, and testing can be performed in the presence of the Customer’s representative.

在顧客監督的每次檢查和測試之前，Jingyoung將為客戶保證，根據本規範，所有方麵的工作都準備好進行檢查和測試。ob体育赛事已經進行了樣品測試的絕緣體不會包含在交付批次中。

常規測試

Jingyong shall carry out routine tests as specified in IEC 61109 (latest version) at their own expense.

Frequently Asked Questions (FAQs)

What is an insulator?

An insulator is a vital component used in the electrical systems to prevent unwanted flow of current to the earth from their supporting points.

絕緣體由絕緣材料，瓷器，玻璃或矽橡膠製成，它們是如此絕緣，即沒有電流可以通過它們。

How many types of insulators?

According to the function, more than 5 types:

• PIN絕緣體
• Suspension Insulator
• Strain Insulator
• Spool insulator
• 保持絕緣體, and so on

According to the voltage:

• 5等級共同絕緣體電壓值：低電壓（LV），中電壓（MV），高壓（HV），超高電壓（UHV），超高電壓（EHV）。
• 3 grades in insulator voltage for power lines or substations: Distribution line insulator voltage, Transmission line insulator voltage, Substation insulator voltage

What tests should do with insulators?

1. 常規測試: Electrical Routine tests, Mechanical Routine tests, Visual examination and check for compliance.
2. 樣品測試，絕緣體隨意從批次隨機接受，應驗證尺寸，溫度循環試驗，機械故障負載測試等。
3. Type Tests, thermal mechanical performance tests carried out in accordance with IEC 575: Dry lightning impulse and Wet power frequency withstand voltage test.

所有測試均按照具體要求補充的相關IEC標準進行。

How to choose the reliable stay insulator manufacturers?

製造商和供應商應具有足夠的資源和能力，以供應最佳的架空線路的絕緣體。

Checking what other people are saying about the insulators from a particular manufacturer. This is possible by reading stay insulator reviews.