• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.3 no.3
• /
• pp.11-16
• /
• 2004

In this study, the characteristics of signals such as acoustic emission, vibration amplitude and noise level which are derived from the abnormal condition of compressor are investigated. The normal condition, vane stick sound and roller defect condition are chosen to analyze the signal in each cases. From the feature extraction of each signals, the dominant parameters of each signals which can identify the abnormal condition are suggested.

• Journal of Industrial Technology
• /
• v.24 no.A
• /
• pp.83-90
• /
• 2004

Generally, electronic appliances are used on the basis of normal power source supply. The power source inevitably includes the abnormal condition, such as, sudden voltage sagging, power interrupt, and induced noises. As the electronic appliances which include micro-controller-based circuits are being increased recently, the controller circuit sometimes malfunctions by the abnormal condition of the power source. This situation causes serious problems such as hitch of electric appliance, fire and medical instrument glitch, which produces serious situations. In this paper, development of power interrupt tester which is highly suitable for an endurance test device under abnormal power source to microprocessor-based circuits is proposed 89C2051 microcontroller is performed to make power interrupt signal, and software controls peripheral hardwares and built-in functions. Experimental results of this study will offer a good application to electronic appliance maker as a test device of hardware and software debugging use.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.365-368
• /
• 1995

Rotary Compressor has many AE(Acoustic Emission) sources according to condition of parts because it is operated with combination of various parts. In this study, analysis of AE raw signal generated form Rotary compressor which artificially-made parts inflicted abnormal condition was carried out. AE raw signals were acquired form high-speed A/D board, and many burst type signals were observed. By analyzing burst type signals which is caused form internal AE source,efficient AE parameters for monitoring and diagnosis were presented.

• Proceedings of the KIEE Conference
• /
• 2008.04b
• /
• pp.131-133
• /
• 2008

This study presents on the analysis fire hazards of drum type electric washing machine. In order to analyze fire hazards fire experiment is conducted. The fire experiment is conducted to simulate under the normal condition and abnormal condition. The experiment under the abnormal condition is simulated in safety device failure, situation of accumulated dust and tracking phenomenon caused by humidity. The results show that fire hazard is high at the abnormal condition. In this paper, we suggest to use the safety device of low operating temperature in electric washing machine for reducing fire hazard.

• Journal of the Korean Society of Safety
• /
• v.22 no.2 s.80
• /
• pp.36-40
• /
• 2007

This study presents on the analysis fire hazards of electric heater. In order to analyze fire hazards fire experiment is conducted. The fire experiment is conducted to simulate normal condition and abnormal condition. The abnormal condition experiment is simulated in which combustibles are placed near by electric heater. Vertical burning test(UL 94) is conducted for the fire retardant experiment. The results show that fire hazard is high in case of abnormal condition. And Material of electric heater has not fire retardant performance. In this paper, we suggest to add temperature fuse in electric heater for reducing fire hazard.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.57 no.3
• /
• pp.328-331
• /
• 2008

This study presents on the analysis fire hazards of drum type electric washing machine. In order to analyze fire hazards fire experiment is conducted. The fire experiment is conducted to simulate under the normal condition and abnormal condition. The experiment under the abnormal condition is simulated in safety device failure, situation of accumulated dust and tracking phenomenon caused by humidity. The results show that fire hazard is high at the abnormal condition. In this paper, we suggest to use the safety device of low operating temperature in electric washing machine for reducing fire hazard.

• Proceedings of the KSME Conference
• /
• 2001.11a
• /
• pp.539-543
• /
• 2001

Almost all rotating machinery has bearings. Bearing is one of the most important part of rotating machinery. Vibration of rotating machinery depend on its bearing conditions. Bearing conditions are followings ; oil gap, bearing type, bearing temperature, bearing oil condition. Especially, bearing oil condition influences on rotating machinery vibration directly. In this paper we have discussed the abnormal vibration of turbine due to oil condition. oil whip problem was occured in the certain power plant. and we had sloved this problem through the control of operating values and alignment.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.10-13
• /
• 2008

Fuel cell systems have witnessed remarkable development in recent years as they offer a clean and efficient alternative for power generation. Testing was conducted to determine the safety performance of a residential fuel cell system when subjected to abnormal operation condition, especially for voltage sag and fuel cut. In case of voltage sag to 198V, its arriving time at rated power had shown a slight lag but there wasn't any noticeable change when operating it between rated voltage(220V) and 10% voltage sag(198V). In case of fuel cut, it also showed stable shut-down characteristics. The test results are being used to develop a new safety evaluation for residential fuel cell system.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.350-354
• /
• 1995

The Tension Leveller of Cold Rolling Mill In POSCO performs levelling the strip in high speed line. But minor variations in operating condition of driving machines such as motor, gear box, and support bearings, a small gap-variation of supporter and strip slip by poor roll revolutions can cause serious problems in the quality of strip. In this study, firstly, A condition monitoring standard for each sensor is made through with the detail analysis of vibration and strip slip. Secondly, An automatic monitoring and diagnosing system was developed to monitor the condition of Tension Leveller, and diagnose the cause of abnormal condition. Finally, A diagnosing algorithm for abnormal condition and man-machine interface (MMI) for easy operation are developed.

• Journal of the Korean Society for Railway
• /
• v.9 no.1 s.32
• /
• pp.29-35
• /
• 2006

Trains in LRT(Light Railway Transit) system usually have shorter car length than metro's because of their smaller passensers demand. Therefore it is very likely that the load condition of LRT system in abnormal operation, in case of which trains are in close proximity by system broke or train rescue works, could be worse rather than in normal operation, in spite of rare probability of abnormal operation. In this study, the target reliability indexes of several abnormal operations are estimated in accordance with the occurrence probabilities of each abnormal operation case and the reliability index of normal operation presented by the specification. From the indexes, load factors for the abnormal operation cases are estimated and the safety evaluation is performed for Yong-in LRT project.