Contact contamination and arc interactions

Witter, G.

doi:10.1109/holm.2005.1518216

Cited by 3 publications

(7 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Silicone materials with chain length of n < 6 are already at room temperature extremely volatile and can be used even as solvents [10,25]. With rising chain length n the vapourpressure decreases and the viscosity increases, and therefore the mobility decreases [15,18,26]. By cross-linking or curing clusters are created also with increasing viscosity or hardness as used for elastomer or sealing/potting materials.…”

Section: A Sources and Detection Of Volatile Siliconesmentioning

confidence: 99%

“…When grinding switchgear piece-parts, especially contact rivets, Silicon based grinding material has to be omitted [12][13][14][15].…”

Section: B Transport and Accumulationmentioning

confidence: 99%

“…Depending on the state of matter of the Silicone a certain transport mechanism is dominant: Since Silicone molecular chains length are always distributed over a certain range volatile Silicones can be present as vapour and liquid with different concentrations [15,26]. 1) Spreading: liquid silicone films can creep over long distances and through small gaps because of its very low surface tension (17-22 mN/m) [3,12,14,18,21].…”

Section: B Transport and Accumulationmentioning

confidence: 99%

“…In a long-term survey published in 2 000 the main root cause for switchgear failures was silicone [16] and also in the field of MEMS Silicone related failures were reported [17]. Apart from Silicones transformed into SiO 2 it was also observed that relatively loose inorganic grinding material as SiC and SiO 2 can be melted within the electrical arc and to be left as solid insulator film on the contact surfaces [12][13][14][15]. The presence of Silicone in the contact area has therefore to be prevented in general.…”

Section: Introductionmentioning

confidence: 98%

“…Over the last decades intensive research concerning Silicone Contamination was carried out and the effect is nowadays well described. Especially Tamai [4][5][6][7][8][9][10][11] and Witter [12][13][14][15] are to be named for publishing numerous papers over many years. The basic mechanism of silicone contamination was observed to be the following: Liquid or vaporous Silicones coming from e.g.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Reliability of hermetically sealed miniature relays in silicone-rich environments

Schrank¹

2012

26th International Conference on Electrical Contacts (ICEC 2012)

View full text Add to dashboard Cite

Organic Silicone materials such as Polydimethylsiloxanes (PDMS) are well-known for more than 60 years to affect the performance of devices with arcing contacts such as switches, relays or motors: liquid or volatile parts of the silicone materials can overcome long distances and penetrate through small gaps and are eventually transformed on contact surfaces within electrical arcs into inorganic silicon-dioxide which is an excellent electrical isolator. Even very small concentrations of silicone can be critical to the performance of the switching devices. Therefore the use of silicone materials is nowadays restricted in applications with switching contacts. Nevertheless silicone related failures of switchgear still occur since the relevance of these phenomena is often underestimated. The first part of this work gives therefore a detailed review of more than 60 years of silicone-related research. In the experimental part of this work relay housings with different sealing categories were investigated regarding their ability to act as reliable barriers: Silicone materials with high and low volatile contents were used within switching experiments in order to determine how reliable i) open, ii) sealed and iii) hermetically sealed relays can be operated within differently saturated silicone ambient. Contact resistance was evaluated as first criteria and after the tests contact surfaces were analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) in order to verify silicone contamination.

show abstract

Section: A Sources and Detection Of Volatile Siliconesmentioning

confidence: 99%

“…When grinding switchgear piece-parts, especially contact rivets, Silicon based grinding material has to be omitted [12][13][14][15].…”

Section: B Transport and Accumulationmentioning

confidence: 99%