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http://dx.doi.org/10.7731/KIFSE.2014.28.4.021

Comparison of Standards for a 1ϕ 2 W MCCB and Study on the Evaluation of Heat Resistance Characteristics  

Choi, Chung-Seog (Dept. of Fire Safety Engineering, Jeonju University)
Lee, Jae-Hyuk (Dept. of Fire Safety Engineering, Jeonju University)
Publication Information
Fire Science and Engineering / v.28, no.4, 2014 , pp. 21-28 More about this Journal
Abstract
This study obtained the following results by analyzing the standards related to a $1{\phi}$ 2W MCCB and evaluating its heat resistance characteristics. Since KS C 8321 corresponds to IEC 60947-2 standards, most of the related regulations are similar. The NFPA, which presents the user oriented safety regulations, contains no details about tests or inspections, etc., but it does specify in detail the regulations directly related to safety. It can be seen that KS C 8321 classifies in detail the items about tests and inspections. However, IEC 60947-2 and IEEE C37.51 simplified the test and inspection items or omitted some of them. When applying thermal stress to an MCCB for 6 hours at $180^{\circ}C$ using a heat resistant experimental device, it was found that the actuator lever was transformed and moved in the tripped state. In addition, most of the fixing hanger was melted down, losing their function. When applying thermal stress to the MCCB at $90^{\circ}C$, it showed nothing peculiar, but the fixing hanger was partly deformed at $105^{\circ}C$ and $120^{\circ}C$. It was found that the fixing hanger was deformed and the name plate was discolored at $150^{\circ}C$. It can be seen from the analysis of the internals of the MCCB that the trip bar has been melted away and that the up and down operator has moved up. The experiment performed by applying a withstanding voltage of 6 kV for 60 s showed that all items remained intact. In addition, the evaluation of the insulation performance performed by applying DC 500 V using an insulation-resistance tester showed good insulation performance.
Keywords
Heat Resistance Characteristics; Thermal Stress; Fixing Hanger; Trip Bar; Withstanding Voltage;
Citations & Related Records
Times Cited By KSCI : 4  (Citation Analysis)
연도 인용수 순위
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