| Step One: Specification of a Junction Box Assembly Begins with the Selection of the Right Size Box—Both in Terms of the Internal Volume and the External Package Size. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Glenair's CostSaver Composite Junction Boxes are ideally suited for use in harsh environments where weight savings and resistance to electromagnetic interference, corrosive fluids, high temperatures, shock and vibration are critical requirements. Compared to aluminum, brass or steel boxes, Glenair's "CostSavers" provide equal or improved RFI/EMI protection, with considerable savings in corrosion-related maintenance. Glenair boxes are outfitted with captive stainless steel cover screws for additional long-term corrosion resistance. In retrofit applications select the most efficient size to fit the existing electronics package. More than one box can sometimes be used efficiently if the electronics package can be conveniently split between two or more boxes. For new application designs, please consult the factory for advice on maximizing the use of internal package space.  
ULTEM® Resin Withstands Long-Term Exposure to Heat, Moisture and Caustic Chemicals Glenair CostSaver Composite Boxes are made from ULTEM 2300® (polyetherimide). ULTEM® is an amorphous thermoplastic polyetherimide offering outstanding high heat resistance, high strength, modulus and broad chemical resistance. Its balance of properties and processability offers design engineers exceptional flexibility and freedom to innovate. ULTEM® resins are inherently flame resistant with low smoke emission. Un-reinforced ULTEM® keeps its hardness, and mechanical properties from -40ºF, up to temperatures of 356ºF. It is radiation-resistant, microwave transparent and is naturally flame-retardant. Reinforced grades have even higher mechanical strength. Because of its unequaled properties, ULTEM® is the ideal replacement for steel and other metals. ULTEM® resins offer: inherent flame resistance, long-term heat resistance, dimensional stability, strength and modulus at elevated temperatures, hydrolytic and chemical stability, and environmental and corrosion resistance. Environmental Properties ULTEM® resin is resistant to mineral acids, mineral salt solutions and dilute bases. Unlike other amorphous resins, ULTEM® polyetherimide also demonstrates unusually good resistance to a wide range of caustic chemicals. ULTEM® resin is unaffected by most hydrocarbons, making it an excellent candidate for aircraft and shipboard applications exposed to gasoline, oils and other fuels. ULTEM® resin is inherently resistant to UV radiation without the addition of stabilizers. Exposure to 1000 hours of Xenon arc weatherometer irradiation (1.55 Watts/m2 irradiance at 340 nm, 63°C) produces a negligible change in the tensile strength of the resin. ULTEM® resin exhibits excellent hydrolytic stability of tensile strength after immersion in water. 10,000 hour immersion tests in water at 212°F (100°C) show that ULTEM® resin’s physical properties remain virtually unchanged, even with repeated cycling from steam pressure to drying in vacuum at room temperature. Thermal Properties An outstanding property of ULTEM® resin is its ability to withstand long-term exposure to elevated temperatures. This high-heat performance, combined with excellent flammability ratings and UL recognition, qualifies ULTEM® resin for demanding high temperature applications. UL rates ULTEM® resin for continuous use at 170°C. The resin’s high glass transition temperature, Tg, of 419°F (215°C), coupled with its high heat deflection temperature of 392°F (200°C) at 264 psi (1.82 N/mm2), contributes to its excellent retention of physical properties at elevated temperatures. The coefficient of thermal expansion is an important design consideration in the production of large composite enclosures, fittings and mating connectors. The table below lists the coefficients of thermal expansion for ULTEM 2300® and the matching values for various metals.
Strength At room temperature ULTEM® resin exhibits strength far beyond that of most engineering thermoplastics, with a tensile strength yield of over 15,000 psi (100 N/mm2) and a flexural strength at 5% deflection of 21,000 psi (145 N/mm2). Even more impressive is the strength at elevated temperatures. At 375°F (190°C), a temperature well beyond the useful rage of most other engineering thermoplastics, ULTEM® retains approximately 6,000 psi (41 N/mm2) tensile strength. The inherent strength of ULTEM® is increased by reinforcement with glass fibers, such as the 30% fiber mix used by Glenair.
Flying Colors! Glenair Composite Boxes, Connectors and Accessories Are Tested and Approved Plating Adhesion Glenair# 9-44-18/TN94-159 The item is tested in accordance with MIL-DTL-38999 and should not exhibit any blistering, peeling or other separation of the units plating when immersed in ice water at 0ºC within 15 seconds after 30 minutes exposure to 200ºC in a circulating oven. Vibration NTS# 973-7369-2 When mounted in a suitable fixture on a vibration table and subjected to vibration in accordance with MIL-STD-167 type 1 for box units & Mil STD-1344, Method 2005 Condition IIl, for fittings and accessories. The tested items should not exhibit loosening of component parts or evidence of damage. Shock NTS# 973-7369-2 When mounted on an Impact plate the Glenair Box is subjected to shock load (Hammer drop) in accordance with MIL-STD-901D, Lightweight, Grade C, there shall be no loosening of parts or evidence of damage. A 400 LB hammer weight attached to a 5 foot long swing arm is raised and released to strike the mounting plate, 9 blows (3 blows in 3 axis). Shock MOD# BR8470 Grade C & F Glenair box is mounted on a suitable fixture and subjected to an initial 70G load progressing to 130G load in accordance with MOD BR 8470 Grade C & F, there shall be no loosening of parts or evidence of damage. Salt Spray Glenair# 9-44-18/TN94-159 The item shall meet Braid Retention, Device conductivity, functional requirements and exhibit no exposure of underplate or base material when subjected to 2000 hrs per MIL-STD-1344 Method 1001. Dust NTS# 973-7369-1 The item must conform to required torque limits and functional requirements within 25% after being subjected to sand and dust test of MIL-STD-202 Method 110. UV Light Resistance GE RDM88050255-6042 There shall be no degradation of the mechanical properties defined in this specification after testing in accordance with ASTM D2565 Impact There shall be no evidence of breaking or cracking of components or other damage, which could affect the product performance. The box will be tested in accordance with MIL-STD-1344 Method 2015 using 8 drops from a height of 2 meters with plate indexed at 36º intervals.
External Bending Moment Glenair# 9-44-18/TN94-159 No evidence of damage detrimental to normal operation when subjected to 3X magnification after being subjected to loads specified in MIL-STD-1344. Temperature Cycling NTS# 575-9249 Item is subjected to a controlled temperature in accordance with MIL-Std-1344 Method 1003 @ –65ºC to 200ºC. After testing the product must not exhibit any cracking, peeling or separation of plating, or other functional damage. Hydrolytic Stability NTS# 878-536 In accordance with ASTMD570-81, Tested Items shall be free of defects detrimental to mechanical performance, no increase in weight greater than 1% and no evidence of cracking, breaking or loosening of component parts when subjected to boiling water. Ice Resistance Glenair# 9-44-18/TN94-159 The item must conform to required torque limits and functional requirements within 25% after being immersed for a minimum of 3 cycles in tap water for 1 minute and placed in an ambient temperature of –65ºC for one hour (until surfaces are completely iced over). Flammability The item flame and after flow-extinguishing time shall not exceed limits defined in Table II of MIL-STD-1344 Method 1012, Smoke index, NES 711 issue 2, and NES 713 issue 3. Burning behavior by Oxygen index, ISO 4589. Water tightness EA# 0C13513-039514 Water tightness and internal pressurization tested at 1 atmosphere, (10 psig). Unit is subjected to a progressive internal pressure test in three feet of water at ambient temperature in increasing increments of 1psig for 2-minute intervals. Out Gassing JPL 081892 Unit is tested in accordance with ASTME 595; maximum allowable weight loss is 10%. After test and bake out the maximum allowable VCM (volatile condensable material) is 0.10%.
Electromagnetic Shielding TRW/ABQ-55C-1186-0 Shielding effectiveness / transfer impedance tests performed in accordance with Military industry standards and customer specific requirements.
Braid Retention Glenair# 9-44-18/TN94-159 Fitting terminations shall be capable of providing 2.5 milliohms maximum resistance between braid and fitting interface when braid is subjected to a tensile load of 5 Kg applied gradually. EMI Shielding MOD# ME1A24S136F Shielding effectiveness Shipboard in accordance with M.O.D. Def Standard 59-41 DRE01. The Glenair box is subjected to an EMI field and measured to the level of shielding effectiveness per the Def standard 59-41 DRE01. Indirect Lightning (Lightning Strike) LT# LT-95-1153, LT-00-1752 Testing in accordance with MIL-STD-1344. Item is subjected to Waveform 1 & 5B using a high current generator. The item must remain functional without degradation of unit’s electrical performance. Waveform 1 and 5B are applied starting at 3ka increasing to 20ka checking continuity measurements at set intervals. Waveform 1 will additionally be subjected to an oscillatory wave starting at 30ka and increasing in 10ka steps until failure in continuity measured.
Humidity NTS# 575-9249 The test specimen is subjected to the humidity test specified in MIL-STD-1344 Method 1002 Test Condition Type ll. The tested item shall exhibit no weight increase, swelling or other evidence of moisture absorption into the base material. Fungus Resistance TBM84-3 Materials used shall be certified as fungus inert in accordance with requirements of MIL-STD-810C, Items must have no evidence of Fungus growth, deterioration or corrosion as a result of testing.
Dust NTS# 973-7369-1 The item must conform to required torque limits and functional requirements within 25% after being subjected to sand and dust test of MIL-STD-202 Method 110
Magnetic Permeability Glenair# 9-44-18/TN94-159 Items shall be tested in accordance with MIL-STD-1344. Ozone NTS# 678-3143 There shall be no evidence of cracking or other damage when item is tested in accordance with MIL-STD-1344 Method 1007. Fluid Immersion NTS# 678-3143 Item shall meet the functional requirements in accordance with MIL-STD-1344 Method 1016 (one sample per fluid). Halogen Free GE 050198 Testing for halogen releases when ignited in accordance with ASTME XX. Radiation Test GE RDM88050255-6042 Gamma Ray, Electron Beam, X-Ray, Ultra Violet, Visible, Infrared, Microwave and Radio Frequency testing preformed. Fitting to Box Conductivity NTS# 575-9249 Max. Voltage drop of 3 millivolts before conditioning and 6 millivolts after conditioning when tested to MIL-STD-1344 Method 3007.
Future Soldier: Weight reduction was the principal goal in selecting the Glenair composite box for the JEDI Warrior Program. The boxes house Lithium battery packs used to power video image and battlefield data collection systems carried by the soldier. The interconnect system and its power supply must be able to withstand the rigors of exposure to mud, dust and abusive handling. The complete solution from Glenair also included our Series 800 "Mighty Mouse" Connector and overmolded cable sets. Ministry of Defense: Glenair composite boxes for the UK Ministry of Defense were subjected to a rigorous testing program, including high-duration shock, EMI and salt-spray corrosion resistance. The MOD has chosen the Glenair boxes as standard replacements for existing aluminium junction boxes which became too expensive to maintain due to high-impact breakage and corrosion. The Glenair boxes now serve in submarines, missile-frigates and other shipboard applications.
Missile-Control: The ability to withstand extremes in shock and vibration, as well as long term corrosion protection and electromagnetic compatibility were baseline requirements for this missile control junction box. The complete system includes fiber optic connectors, termini and cabling. Interconnect systems of this type must be able to sit idle for many years, and then perform flawlessly in the blink of an eye. Fiber-Optic Storage: In this application, Glenair was able to provide a complete, turnkey interconnect assembly which included both the lightweight composite box, as well as the conduit and the fiber optic interconnects.
Dazzle the Mess Deck with Your Mastery of Composite Thermoplastic Terminology Abrasion: The wearing away of material by friction. Glass reinforcement in composites is highly resistant to abrasion by other materials. Bond Strength: The strength of adhesion between bonded surfaces or a measure of the stress required to separate a layer of material from the base material to which it is bonded. Catalyst: A chemical additive, such as benzoyl peroxide, which accelerates the cure of a thermoplastic compound. Cavity: The space (depression) inside a mold, or the space between matched molds wherein a resin is poured. Molds are designated as Single-Cavity or Multiple Cavity depending on the number of depressions. Coefficient of Thermal Expansion (CTE): The measured amount a material shape will change for each degree of temperature change. Composite: A homogeneous material created by the synthetic assembly of two or more materials (for example, glass fiber and a compatible polymer resin) to obtain specific characteristics and properties. Continuous Heat Resistance: The maximum temperature a material should be subjected to in a continuous application. Below this temperature the material performs at acceptable levels. Above this temperature the material may decompose, melt, or otherwise fail in an application.
Creep: The slow movement of a plastic material over time. Cross-linking: The creation of chemical links between molecule chains which occurs in all thermosetting resins. Cure: The completion of the polymerization process which alters plastic materials from liquids into a solids. Dielectric Strength: The ability of a material to act as an electrical insulator. Dielectric strength is a measure of the electrical voltage which can be built up on one side of a material before it is conducted to the other side. Elasticity: The ability of a plastic material to recover its original shape after deformation. Fiber: A single glass filament. Filament: A single, threadlike fiber of glass. Flammability: The measure of how fast a material will burn under controlled (ASTM D-635/UL E 84) test conditions. Flexural Strength: Also known as bending strength. It describes how much of a non-moving load can be applied before a material yields or breaks. FRP: Acronym for plastic reinforced by fiber glass or fiber. Glass Content: Percentage of glass in the compound. GRP: Glass-reinforced plastic, polymer or polyester. This term is more commonly used in Europe. Hygroscopic: Any material that absorbs moisture from the air. Hydrophobic: A material’s moisture resistant or moisture repelling capability. Impact Strength: The impact strength of a material is the measure of how much energy it will absorb when it is broken by a moving weight. There are many different test methods for measuring impact strength or shock, including MIL-STD-901D. Matrix: Term used to describe the resin component of a polymer composite. Outgassing: Release of solvents and moisture from composite parts under the hard vacuum of space. Pigment: An additive used to impart color in some composite plastics. Reinforced Plastic: A plastic with relatively high stiffness or very high percentage of strength fibers embedded in the composition. Resin: In reinforced plastics, the material used to bind together the reinforcement material; also known as the "matrix." Rib: A raised member in a fabricated or molded part designed to add strength or stiffness to the surface area. Specific Gravity: The weight of a material in relation to the weight of an equal volume of water. A material with a Specific Gravity of 2.0 weighs twice as much as an equal volume of water. Higher numbers indicate heavier materials. Tensile Strength: The maximum tensile load per unit area of original cross section sustained by a material specimen during a tension test. It is expressed as psi or N/mm2. Thermal Coefficient of Expansion: The measurement of how much the length of a material will change when it is heated or cooled. Thermal Conductivity: A measure of the transfer of heat by conduction; also known as the K factor. It describes in BTU’s how much heat is transferred from one side of a material plate to the other side. UV Stabilizer A chemical compound which improves a material’s resistance to degradation from ultraviolet radiation. Box Specification Worksheet Glenair brings a unique strength to junction box systems: the ability to build a turnkey assembly—wired, terminated, tested and complete with all the necessary fittings and accessories. We are the only nonmetallic enclosure manufacturer in the world which can supply an integrated interconnect system of this type. And we are pleased to provide this service at small quantity and prototype levels. This worksheet summarizes the major decision points in the design and development of an interconnect box assembly.
Select/Indicate Connector and Fitting Locations: Indicate the locations of your selected connectors and fittings. You may simply describe the devices in the space provided (“Two jam-nut 15 pin D38999 Series III Connectors go on Side "A") or you may sketch the fittings and connectors in place with appropriate labels. There are no limits to the size and number of penetrations other than the physical boundaries of the box surfaces. Use the dimensional information published with each connector or feed-through series, or call our factory for assistance. Input-Output Device Position Template This template may be used to indicate initial positioning of connectors, feed-throughs and fittings such as ground lugs. Indicate the location of all special markings or labels including correct wording/numbering.  
The structural ribs located on the box sides are provided to increase the overall strength of the box. The ribs may be removed to accommodate additional fittings if necessary. For additional assistance in locating connectors and fittings please consult the factory. For custom fittings, such as specially designed doors or lid covers, please consult the factory. Application engineering for customer specified box assemblies is provided free upon request.
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