The meanings of letters in insulator models

The letters in insulator models usually have specific meanings, which are used to indicate the type, structure, performance and other characteristics of insulators.

Taking common insulator models as examples, the specific meanings of different letters are as follows:

I. Classification and Meanings of Common Letters Type and Application Identification

U: Indicates disc suspension insulators (e.g., U70BP/146).

S: Indicates cross-arm insulators (e.g., the "S" in SC-210).

E: Indicates low-voltage line insulators (e.g., the "E" in ED-1;

the "D" stands for butterfly-type). X: Indicates suspension insulators (e.g., XP-70; the "P" stands for standard type).

C: Indicates porcelain material (e.g., the "C" in SC-210, distinguishing from glass material).

Structure and Connection Method B: Indicates ball-and-socket connection (e.g., the "B" in U70B).

L: Indicates Clevis-and-tongue connection (e.g., UL-70, relatively rare).

P: Indicates anti-pollution type (e.g., the "P" in U70BP/146; anti-pollution insulators usually have a larger creepage distance).

Performance and Parameter Characteristics Letters before numbers:

Usually related to mechanical load, e.g.: "70": Represents a rated mechanical failing load of 70kN (e.g., U70BP/146);

"210": Represents a mechanical bending failing load of 2.5kN (e.g., SC-210; "210" is an old model labeling method).

Other special identifications: "W": Indicates pollution-resistant type (e.g., XWP-70, similar in meaning to "P");

"Z": Indicates DC insulators (e.g., XZ-70).

II. Typical Model Interpretation Examples U70BP/146

U: Disc suspension type; 7

0: Mechanical failing load of 70kN;

B: Ball-and-socket connection;

P: Anti-pollution type;

146: Structural height of 146mm.

ED-1 E: Low-voltage line type;

D: Butterfly type;

1: Design serial number (used to distinguish different specifications, e.g., ED-2, ED-3, etc.).

SC-210 S: Cross-arm insulator;

C: Porcelain material;

210: Mechanical bending failing load of 2.5kN (in the old standard, "210" corresponds to 2500N).

III. Industry Standard Basis for Letter Meanings

The naming of insulator models complies with the national standards GB/T 2317.1-2000

Test Methods for Electric Power Fittings -

Part 1: Mechanical Tests and GB/T 7253-2008 Units for String of Disc Suspension Insulators - Dimensions and Characteristics.

The combination of different letters shall follow the rules below: First letter: Prioritize indicating the insulator type (suspension, cross-arm, butterfly, etc.);

Middle letters: Supplement structural characteristics (connection method, anti-pollution performance, etc.);

Numbers: Specify quantitative parameters such as mechanical load and structural dimensions;

Suffix letters: Distinguish materials (porcelain, glass) or special applications (DC, pollution-resistant, etc.).

IV. Notes Differences between standards: Some imported insulators or old models may adopt different naming rules (e.g., using "U" to indicate mechanical load instead of type), and confirmation shall be made in combination with specific technical parameters.

Understanding combined with numbers: Letters need to be matched with numbers to fully interpret the model. For example, "1" in "ED-1" represents a specific specification, while "E" and "D" represent the type.