Fire risks due to unintentionally energized metal structures

2017 ◽  
Vol 35 (5) ◽  
pp. 415-426
Author(s):  
Michael C Stern ◽  
Sean C O’Hern ◽  
Timothy L Morse ◽  
Justin Bishop ◽  
Harri Kytömaa
Keyword(s):  
Molten Metal ◽  
Air Conditioning ◽  
Electrical Equipment ◽  
Protection Device ◽  
Electrically Conductive ◽  
Metal Structures ◽  
Self Heating ◽  
Overcurrent Protection ◽  
Electrical Connections ◽  
Combustible Materials

Improperly grounded electrical equipment can lead to a fire within a home. If electrical equipment in a home is not properly grounded, then an electric fault may cause metal structures (such as heating, ventilation, and air conditioning ducts, metal framing, or screws, nails, and bolts) to become energized without triggering an overcurrent protection device. Electrical connections between these energized materials and grounded objects create an unintended path to ground and can lead to prolonged self-heating that can cause ignition in combustible materials such as wood framing, cellulosic insulation, and other lightweight combustibles. Alternatively, molten metal that is capable of igniting lightweight combustibles can be ejected if the energized surface contacts a well-grounded objected. This article presents results from experiments performed to investigate conditions that cause fires as a result of stray energization of electrically conductive construction items. Resistances, types of nearby combustibles, and other factors were evaluated.

Package-Interposer-Package (PIP): A Breakthrough Package-on-Package (PoP) Technology for 3D-Integration

2012 ◽  
Vol 2012 (1) ◽  
pp. 000561-000567
Author(s):  
Rabindra N. Das ◽  
Frank D. Egitto ◽  
Barry Bonitz ◽  
Erich Kopp ◽  
Mark D. Poliks ◽  
...  
Keyword(s):  
System Integration ◽  
Integrated Approach ◽  
Power Delivery ◽  
Solder Paste ◽  
3D Integration ◽  
Electrically Conductive ◽  
Reflow Temperature ◽  
Electrically Conductive Adhesive ◽  
The Stability ◽  
Electrical Connections

Package on Package (PoP) stacking has become an attractive method for 3D integration to meet the demands of higher functionality in ever smaller packages, especially when coupled with the use of stacked die. To accomplish this, new packaging designs need to be able to integrate more dies with greater function, higher I/O counts, smaller pitches, and greater heat densities, while being pushed into smaller and smaller footprints. A new 3D “Package Interposer Package” (PIP) solution is suitable for combining multiple memory, ASICs, stacked die, stacked packaged die, etc., into a single package. This approach also favors system integration with high density power delivery by appropriate interposer design and thermal management. Traditional Package on Package (PoP) approaches use direct solder connections between the substrates and are limited to use of single (or minimum) die on the bottom substrate, to reduce warpage and improve stability. For PIP, the stability imparted by the interposer reduces warpage, allowing assemblers of the PIP to select the top and bottom components (substrates, die, stacked die, modules) from various suppliers. This mitigates the problem of variation in warpage trends from room temperature to reflow temperature for different substrates/modules when combined with other packages. PIP facilitates more space-efficient designs, and can accommodate any stacked die height without compromising warpage and stability. PIP can accommodate modules with stacked die on organic, ceramic, or silicon board substrates, where each can be detached and replaced without affecting the rest of the package. Thus, PIP will be economical for high-end electronics, since a damaged, non-factional part of the package can be selectively removed and replaced. A variety of interposer structures were used to fabricate Package Interposer Package (PIP) modules. Electrical connections were formed during reflow using a tin-lead eutectic solder paste. Interconnection among substrates (packages) in the stack was achieved using interposers. Plated through holes in the interposers, formed by laser or mechanical drilling and having diameters ranging from 50 μm to 250 μm, were filled with an electrically conductive adhesive and cured. The adhesive-filled and cured interposers were reflowed with circuitized substrates to produce a PIP structure. In summary, the present work describes an integrated approach to develop 3D PIP constructions on various stacked die or stacked packaged die configurations.

scholarly journals Justification of the active method of protecting the insulation of submersible electric motors

2019 ◽  
Vol 124 ◽  
pp. 02003
Author(s):  
V. A. Trushkin ◽  
O. N. Churlyaeva ◽  
R. V. Kozichev
Keyword(s):  
Physical Properties ◽  
Electrical Breakdown ◽  
Electrical Equipment ◽  
Working Environment ◽  
Operating Parameters ◽  
Insulation Resistance ◽  
Electric Motors ◽  
Electrically Conductive ◽  
Active Method ◽  
Conductive Properties

The article provides an analysis of the properties of the working environment of submersible electrical equipment. The influence of the operating parameters of electrical equipment on the physical properties of the fluid (its electrically conductive properties) is considered. Mathematical confirmation of the implementation of electroosmosis in the capillaries of the insulation of submersible electric motors is given. The rationale for the active method of protecting submersible electrical equipment from reducing insulation resistance and preventing electrical breakdown is given.

Microprocessor-based overcurrent protection for PV powered air-conditioning system

1997 ◽  
Vol 38 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Wagdy R. Anis ◽  
Hamid H.B. Metwally ◽  
Abd El-Shakour M. El-Samahy
Keyword(s):  
Air Conditioning ◽  
Air Conditioning System ◽  
Overcurrent Protection

Self-heating of electrically conductive metal-cementitious composites

2019 ◽  
Vol 30 (15) ◽  
pp. 2234-2240 ◽  
Author(s):  
Salam R Armoosh ◽  
Meral Oltulu
Keyword(s):  
Large Scale ◽  
Heating Temperature ◽  
Low Cost ◽  
Cement Composite ◽  
Input Voltage ◽  
Cement Composites ◽  
Electrically Conductive ◽  
Self Heating ◽  
Metal Materials ◽  
Increasing Demand

Given the increasing demand for higher performance and economic gains in cement composite products, the self-heating performance of cement composites is becoming ever more assorted and progressive. This study investigates the effects of metal materials on self-heating of cement composites. Cementitious composite cubes containing up to 20% of metal materials were tested to improve their conductivity and hence investigate their performance in terms of electrical resistance heating. The metals that were studied were copper, iron, and brass shavings. The test variables were types of metals and input voltage. The tests showed that the presence of metal components improved cementitious cubes’ conductivity, and hence, they transferred heat. In addition, the tests showed that the heating temperature changed with the type of metal and input voltage. Analysis of energy consumption, heating rate and maximum surface temperatures was performed to evaluate the possibility of using metal materials as low-cost heating elements in large-scale heating systems.

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