1 RADSOK RADSOK® HIGH AMPERAGE ELECTRICAL TERMINALS TECHNICAL BRIEF Revised: May 2001 DISCLAIMER The information presented herein is believed to be correct at the time of printing and has been compiled from data collected from various sources. This informa- tion is not warranted to potential buyers of RADSOKelectrical terminals. Every user of these electrical terminals must determine the RADSOKsuitability for their own applications. Manufacturing Facility KonneKtech 34230 Riviera Drive Fraser, MI 48026 Sales Office Dixon Engineering Sales Int’l, Inc. 1200 West Eleven Mile Road Royal Oak, MI 48067 Email:[email protected]
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RADSOKRADSOK® HIGH AMPERAGE ELECTRICAL TERMINALS
TECHNICAL BRIEF
Revised: May 2001
DISCLAIMER
The information presented herein is believed to be correct at the time of printingand has been compiled from data collected from various sources. This informa-
tion is not warranted to potential buyers of RADSOK electrical terminals.Every user of these electrical terminals must determine the RADSOK suitability
for their own applications.
Manufacturing Facility
KonneKtech34230 Riviera Drive
Fraser, MI 48026
Sales Office
Dixon Engineering Sales Int’l, Inc.1200 West Eleven Mile Road
Test Data for Various RADSOK® Terminals……...…………………….. 20
Table of Contents
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RADSOK® Terminal Grid
Pin inserted into RADSOK® “Grid”
Figure 1: Hyperbolic Grid
WWWWHAT is a RADSOK® TERMINAL?HAT is a RADSOK® TERMINAL?HAT is a RADSOK® TERMINAL?HAT is a RADSOK® TERMINAL?
RADSOK means Radial Socket and is aregistered trademark of KONNEKTECH, Inc.The RADSOK terminal is a patented highperformance hyperboloid socket and pinstyle electrical contact system for applica-tions 30 amps and above. Hyperboloidconnectors offer superior performancewhen compared with standard pin andsocket connectors. In the RADSOK ter-minal, multiple contacting elements are hy-perbolically arrayed around the inner di-ameter of the socket. In addition, each ofthe contact elements is skewed with re-spect to the axial direction of the terminal.The result is the multiple contact surfaces,comprising what is referred to as the “grid.”This is illustrated in Figure 1.
When viewing the grid profile, a hyperbolashape is seen that is the basis of theunique RADSOK terminal. The hyperbolicconfiguration results in a mechanical inter-ference between an inserted pin and thecontact elements. When a pin is insertedinto the socket, the contacting elements ofthe grid mechanically wrap around the pinproviding pressure (normal force) neces-sary for a superior electrical connection.
The grid of the RADSOK terminal ismanufactured from highly conductive, hightensile strength beryllium copper. The highflexible modulus properties of berylliumcopper result in excellent electrical contactwhen formed into the hyperbola shape.The grid is produced by a progressive die inhigh-speed four-slide stamping machines,which assures part uniformity. The hous-ings are copper barrels produced on ex-tremely accurate transfer presses. Thesemanufacturing methods result in a highquality electrical terminal that is cost com-petitive while out-performing all other formsof terminals.
KEY FEATURES of the RADSOK® KEY FEATURES of the RADSOK® KEY FEATURES of the RADSOK® KEY FEATURES of the RADSOK® TERMINALTERMINALTERMINALTERMINAL
Low Contact Resistance and High Cur-rent Capacity – The RADSOKterminalgrid provides a greater surface area of elec-tricalcontact per contacting element thanstandard terminals. RADSOKterminalsdo not relax as a result of repeated inser-tion, which occurs in standard terminals.The associated millivolt loss that is com-mon in standard terminals due to repeatedinsertion relaxation does not occur in theRADSOKterminal. The result is superiorelectrical transfer that does not deterioratefrom repeated insertion.
Adjustable insertion/extraction force –The insertion/extraction force of the RAD-SOK terminal can be adjusted to somedegree by adjusting the coatings used toplate the grid and the pin. It is possible to
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customize the materials and coatings usedfor the RADSOK terminal to optimize therelationship between performance objec-tives and cost. Typically, an insertion forceof at least 1.5 pounds is necessary to as-sure operational integrity of the RADSOKterminal.
Vibration Resistance/Off Axis InsertionTolerance - The hyperbolic grid of theRADSOK terminal assures full contactwith an inserted pin. Tests have confirmedthat when subjected to vibration, this hyper-bolic elastic grid maintains electrical conti-nuity. This unique feature also provides forsome axial misalignment without sacri-fice of electrical contact.
Excellent Durability - Certain applicationsrequire repeated insertion/extraction cycles.The opportunity to customize the selectionof material and plating combinations tomaximize the cost versus performance re-quired is unique to the RADSOK terminal.Low cost designs capable of thousands ofcycles while maintaining high and consis-tent conductive characteristics can beachieved when RADSOK terminals arecustomized to a specific application.
Self-Cleaning - Ideally, care should betaken to assure that electrical terminals re-main clean and free of contaminates to pre-vent voltage loss and heating. The designof the RADSOK terminal provides a de-gree of self-cleaning. As the pin is insertedinto the socket, the grid elements provide awiping action that remove minor contami-nants from the pin. The spaces betweenthe grid elements provide space for con-taminates.
Since the RADSOK terminal does not relyon mechanical fasteners for electrical con-nection, the terminal can be installed or dis-connected quickly without the need of spe-cial tools. This results in shorter assembly
time and easier component removal. Whena threaded style terminal is not properly in-stalled, [over or under torque] electricalcontact properties can be compromised.Results can be contact overheating, contacthousing damage, and ultimate failure of theelectrical connection. Use of the RAD-SOK terminal eliminates this variabilitysince achievement of an acceptable level oftorque is not required. The SurLok posi-tive retention feature can be added to in-crease the robustness of the assembly op-eration. This feature is recommendedwhen individual electrical connections arerequired and retention is not available via acontact housing.
RADSOKRADSOKRADSOKRADSOK®®®® TERMINAL PRODUCT TERMINAL PRODUCT TERMINAL PRODUCT TERMINAL PRODUCT RANGE and AVAILABLE OPTIONSRANGE and AVAILABLE OPTIONSRANGE and AVAILABLE OPTIONSRANGE and AVAILABLE OPTIONS
The RADSOK terminal can be made inany size greater than 3.6mm pin diameter.Presently available and in productionare 6.0mm, 8.0mm and 10.3mm car-tridges. Designs and prototypes havebeen made of the following sizes:
• 3.6mm
• 4.3mm
• 6.0mm “short”
• 10.3mm “short
• 12.3 mm
• 14.0mm
• 17.9mm
• 23.0mm
• 40.0mm
New designs are constantly being devel-oped with the 3.6mm terminal expected tobe the next size available for production.
Some options available with the RAD-SOK terminals include:
• Holders to connect the RADSOK ter-minal to wire or cable.
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• SurLok positive retention feature.This is a detent-locking feature thatsnaps “home” and reduces the likeli-hood of inadvertent decoupling. Thisfeature can also be used to provideconfirmation that the connector is fullymated.
• SealTac ingress protection. This is aseal option that protects the contact in-terface from the environment. In itssimplest form, the seal is a die-cutEPDM washer inserted into the entryend of a closed end RADSOK car-tridge that seals against the pin wheninserted.
• Data terminals -- Some applications re-quire voltage monitoring at the connec-tor. This feature allows voltage monitor-ing via a standard 0.25-inch-spade ter-minal that can be attached to larger ter-minal sizes.
The RADSOK cartridge can be incorpo-rated into conductive housings or holdersand be terminated with a threaded fastener,a crimp barrel, a finger crimp, or any of sev-eral other termination methods (See Figure2).
Figure 2: Optional Termination Methods
APPLICATION DETAILS for the APPLICATION DETAILS for the APPLICATION DETAILS for the APPLICATION DETAILS for the RARARARADDDDSOKSOKSOKSOK®®®® TERMINAL TERMINAL TERMINAL TERMINAL
The 6mm, 8mm, and 10.3mm RADSOKcartridges are presently tooled for produc-tion. Other sizes have been developed andwill be available, as customers require. Be-sides the basic cartridge, the RADSOKterminal can be designed to incorporateother features, which enhance the terminalsflexibility and appeal such as the SurLokand SealTac features.
There are three options to consider whenspecifying RADSOK terminals:
• Purchase RADSOK terminals for in-clusion in an assembly.
• Purchase RADSOK terminals assem-bled into holders ready for crimping orfastening to cable or other components.
• Purchase assemblies from KONNEK-TECH with the RADSOK terminal incor-porated.
For applications requiring RADSOK termi-nals only, recommended assembly proce-dures are included in the “Guidelines forRADSOK Terminal Assembly”, locatedin the Appendix. This document also in-cludes recommended press fit dimensionsto install the RADSOK Terminal cartridgeinto conductive holders. The “Dimensionsof RADSOK Terminal, Pin and Recep-tacle” document found in this manual pro-vides additional dimensions to aid manufac-turing cartridge holders and pin specifica-tion development. For custom applications,KONNEKTECH offers a complete in-houseterminal development and prototype depart-ment. The RADSOK terminal is ideallysuited for applications requiring quick con-nect or disconnect with high current flow.The two basic terminal configurations arein-line and 90°. These configurations referto how the axis of the cartridge is orientedwith respect to the cable conductor. Within-line, the RADSOK terminal is on the
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same axis as the conductor, or in-line to theconductor.
For 90° configurations, the RADSOK ter-minal axis is 90° or perpendicular to theconductor. There are numerous options toconsider when designing the cartridge hold-ers for each of the configurations. The hold-ers can be made as metal stampings, im-pact extrusions or from CNC machining,depending on the quantity and style re-quired.
TYPICAL APPLICATIONS for the TYPICAL APPLICATIONS for the TYPICAL APPLICATIONS for the TYPICAL APPLICATIONS for the RARARARADDDDSOK® TERMINALSOK® TERMINALSOK® TERMINALSOK® TERMINAL
• Battery (cell) terminals
• Battery-to-battery connections
• Bus bar connections
• Alternator connections
• Automotive power handling connections
• Electronic Communication PowerHandling
• APU Power connections
CHOOSING the PROPER RADSOK® CHOOSING the PROPER RADSOK® CHOOSING the PROPER RADSOK® CHOOSING the PROPER RADSOK® CONTACT SIZECONTACT SIZECONTACT SIZECONTACT SIZE
It is important to understand the pin diame-ter is the referenced RADSOK terminalsize. For example, a 6 mm RADSOK ter-minal refers to 6 mm pin. When determin-ing the proper RADSOK terminal size touse, it is important to know the following pa-rameters for the application:
• Steady state current flow requirements
• Expected ambient temperature
• Acceptable temperature rise
• Environment
The above four items are inter-related toeach other. When an electric current flowsthrough a terminal, there is a correspondingrise of temperature in the terminal. This iscalled Joule or I2R heating. As temperatureincreases, the contact will not be capable ofcarrying the same current flow. As ambienttemperature increases, the capability of acontact to carry current that would be possi-ble at a lower ambient temperature de-creases. This can be referred to as contactderating.
Data has been collected on several RAD-SOK terminal sizes. Some data, includ-ing current-temperature data that shows thetemperature rise performance of each ter-minal size at a specified load is available.This stabilized temperature rise data is pre-sented in graphical form in the APPENDIXand can be used as a tool to determine anappropriate RADSOK terminal size.
When sizing a RADSOK terminal for aparticular application, it is important that theresulting terminal temperature be compati-ble with the working environment.
TECHNICAL DESCRIPTION of the TECHNICAL DESCRIPTION of the TECHNICAL DESCRIPTION of the TECHNICAL DESCRIPTION of the RADSOK® TERMINALRADSOK® TERMINALRADSOK® TERMINALRADSOK® TERMINAL
RADSOK Terminal Assembly andManufacturing Process
To understand the RADSOK terminalprinciple, begin with the assembly andmanufacturing process. The patented hy-perboloid design of the RADSOK makes ita unique socket and pin connector. Expen-sive hyperboloid terminals produced by ar-raying wire in a radial configuration withinthe connecter have been available for sometime.
The RADSOK terminal is uniquely differ-ent from older hyperboloid designs that re-quire the wires to be assembled in place bysome type of stitching process. These wires
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are assembled in place on a form thatwraps around the inserted pin (see Figure1). The RADSOK terminal was developedto achieve the favorable conductive and lowinsertion characteristics of the hyperboloidwire terminal designs at a lower cost utiliz-ing state-of-the-art manufacturing systems.
The heart of the patented RADSOK termi-nal is referred to as the “grid.” The “grid” isproduced in a progressive die and is manu-factured from high strength yet highly con-ductive beryllium copper (BeCu). The lad-der-like configuration of the grid can beseen in Figure 3.
The grid is then rolled into a cylinder. Thefinger-like extensions (see Figure 3) on oneside of the grid are flared radially outward90 degrees from the cylinder (see first im-age on left of figure 4). The formed grid isthen inserted into a tube that is referred toas the inner barrel. This can be seen in fig-ure 4, the second image. In the next stepof the assembly process, the flared end ofthe assembly is pressed into a larger tubecalled the outer barrel. Parts for this opera-tion can be seen in figure 4, depicted by thethird and fourth images.
The grid fingers are now firmly secured onone end of the terminal. Next, the fingerson the opposite end of the terminal areflared in a similar fashion. In the next stepthe hyperbolic characteristic is introducedto the grid. While the twist on the grid isheld, the other half of the outer barrel is
pressed over the grid fingers, securingthem and locking the grid twist in place.The sixth image in figure 4 shows the com-pleted and patented RADSOK terminalcartridge
A new version of this design that replacesthe 2 outer barrels with a single barrel hasrecently been patented and will soon be inproduction. This new design results in lesspart complexity and allows the assemblyprocess to be streamlined and highly auto-mated.
Hyperbolic Grid Twist of RADSOKTerminal
Taking a closer look at the grid, a graphicalapproach will be used shown in Figure 5.Line A depicts a single grid element prior togrid twist. Line A’ is the skewed elementthat results when the twist is placed on thegrid. The twist is stipulated by the rota-tional angle θ and is typically 45 degrees.
Further observation of figure 5 shows thatA’ is slightly longer than A indicating thatthe grid elements of the terminal are in ten-sion. The two-dimensional top view in fig-ure 5 shows that the grid element forms achord on the circle. If the element is ar-
Figure 3: BeCu Grid
Figure 4: RADSOK® Assembly Process
Figure 5: Hyperbolic Rotation Theory
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rayed around the center of the circle andcylinder of the three-dimensional view, thehyperbolic profile takes shape as shown infigure 6. The waist or neck where the innerdiameter of the cylinder is reduced can beclearly seen.
The RADSOK terminal is designed tohave a slight clearance between the outerdiameter of the pin and pre-twisted innerdiameter of the socket. Referring back tofigure 1, as the pin is inserted into thesocket, the pin displaces the radial grid ele-ments, placing additional tension on theconnection.
RADSOK Terminal Principle
Figure 7 shows the forces acting on a gridelement after the RADSOK terminal is
formed into a hyperbolic grid. The force ex-erted on the pin is referred to as the normalforce. This means that the force is perpen-dicular to, or normal, to the object. Thisforce is the basis for good electrical con-duction and therefore is critical to achievinglow electrical resistance.
When two flat electrically conducting bodiesare in contact with one another, the actualcontact area is limited. Even surfaces pol-ished with great precision will exhibit peaksand valleys under a microscope.
When two flat surfaces are in contact, onlythe peaks of these surfaces are actuallytouching. These areas of contact are re-ferred to as asperities or “a” spots. As thenormal forces between these surfaces in-crease, so will the cross sectional area ofthe a-spots. A depiction of this can be seenin Figure 8.
These asperities are the actual contact in-terfaces between a pin and receptacle ele-ments through which electrical currentflows. The lines illustrate how electricalcurrent flows through these asperities. In-creasing the normal force increases thecross sectional area of the a-spots in thevalleys which were not touching prior to theintroduction of force, resulting in additionala-spots contacting. The additional contactdecreases the millivolt drop of the terminaland reduces heat build-up.
Resistance in the terminal is also de-creased by the additional asperities whereresistance is the property that opposeselectrical current flow. There are several
Figure 6: Hyperbolic Profile
Figure 7: Grid Element Force Distribution
Figure 8: Contact of Flat Surfaces
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components of resistance associated withelectrical terminals. The first is the materialresistance comprising the terminal. Thisproperty is referred to as “bulk resistance”and is defined by Equation 1.
With the RADSOK terminal, the normalforce can be altered by increasing or de-creasing pin diameter. However, as notedbelow, the relationship between pin sizeand contact resistance should be carefullyconsidered to assure that optimum perform-ance is achieved. Additional effort requiredto insert the pin is directly proportional to
normal force as shown by Equation 4.Equation four is derived from the forces de-picted in the free-body-diagram in Figure 9.
Contact or constriction resistance is relatedto the applied normal force per Equation 3.After a certain point, increasing insertionforce and corresponding normal force re-sults in diminishing returns in decreasingthe contact or constriction resistance.
Figure 10 shows that the optimum balancebetween insertion force and contact resis-tance for the 10.3 mm RADSOK occursaround 45 degrees of grid rotational twist.
The third source of resistance is associatedwith films or oxides that may form on thesurfaces between the mating surfaces.This is referred to as film resistance or RF.The wiping action of the RADSOK termi-nal reduces these films during pin insertion/extraction. In addition to the self-cleaningaction of the terminal, higher voltages typi-cally associated with the use of the RAD-SOK terminal puncture these films.
RL
areaB = ρ
Equation 1
Where: ρ (rho) is the material resistance. Unitsare ohm-centimeters (Ω-cm)
L = Length of the conducting material
Area = Cross-sectional area of conductor
Equation 2 ρσ
=1
Where: σ (sigma) is the conductivity of the ma-terial . Units are mho-cm or cm/ohm (cm/Ω).
Equation 3R
NC ∝
1
Where: N = Normal Force
Equation 4 NF
=µ
Where: N = Normal Force
F = Pin Insertion Force
µ (mu) = Coefficient of Friction
Resistance is a material constant and is re-lated to material conductivity (Equation 2).
The resistance corresponding to the a-spots is referred to as the constriction resis-tance. This is so named because the a-spots constrict the flow of current betweenthe contacting surfaces. According to Bow-den and Tabor [1], constriction resistance isproportional to normal force and is shownbelow by Equation 3.
Figure 9: Forces on Pin
OptimumRADSOKConfiguration
0
50
100
150
200
250
DegreeofTwist
0
2
4
6
8
10
12
14
16
18
10 20 30 40 50 60 70 80
Figure 10: Insertion Force vs. Resistance
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The total resistance associated with theRADSOK Terminal is then:
RT = RB+RC+RF
Using materials with high electrical conduc-tivities can minimize RB. Typical values ofelectrical conductivities for several metalsare listed in Table 1. The table is organizedin decreasing order of conductivity; silverbeing the best electrical conductor.
Materials for the RADSOK terminal arechosen based on electrical, mechanical andthermal properties. Ideal materials wouldhave the highest values for each of theseparameters. With electrical terminals, abalance between these parameters mustbe maintained because a high value in onearea can mean a low value for another pa-rameter for the same material. For in-stance, a material with a desired high elec-trical conductivity typically has lower valuefor material strength.
To aid in identifying the components of theRADSOK, Figure 11 shows a cut-awayview of the terminal.
TERMINAL GRID
The grid of the RADSOK Terminal is fab-ricated from a beryllium copper alloy. Thisalloy provides excellent tensile or flexmodulus properties required to provide ahigh degree of contact normal force. Table2 shows the properties of the beryllium cop-per used for the RADSOK terminal.
Corrosion Resistance of BerylliumCopper. Beryllium copper alloys are com-patible with aqueous solutions of most al-kali hydroxides, hot or cold, except for am-monium hydroxide that can cause stresscracking. The alloy also resists corrosion incold, concentrated sulfuric acid and hot orcold diluted sulfuric acid. This alloy also ex-hibits a low rate of corrosion in salt-waterenvironments.
Exposure to the above-described solutionsforms a thin passive film on the surface ofmetal. This film will grow in the presence ofwater or oxygen. This film growth takes
Material Resistivity Conductivity Relative
(ohm-meter) (mhos/meter) Conductivity
Silver 1.59E-08 6.30E+07 1.06
Copper 1.68E-08 5.96E+07 1.00
Gold 2.21E-08 4.52E+07 0.76
Aluminum 2.65E-08 3.77E+07 0.63
Beryllium Copper 3.45E-08 2.90E+07 0.49
Beryllium 3.56E-08 2.81E+07 0.47
Zinc 5.90E-08 1.69E+07 0.28
Brass 6.16E-08 1.62E+07 0.27
Nickel 6.93E-08 1.44E+07 0.24
Iron 9.61E-08 1.04E+07 0.17
Platinum 1.05E-07 9.52E+06 0.16
Palladium 1.05E-07 9.49E+06 0.16
Phosphor-Bronze 1.15E-07 8.70E+06 0.15
Tin 1.16E-07 8.62E+06 0.14
Lead 2.08E-07 4.81E+06 0.08
Beryllium Nickel 2.46E-07 4.07E+06 0.07
Stainless Steel (301) 7.14E-07 1.40E+06 0.02
All values based on room temperature (~20oC).The relative conductivity is based on copper.
place at the expense of the base metal thatis dissolved through corrosion. Protectionagainst corrosion can be accomplishedthrough plating, which is discussed later.
BARRELS
The inner and outer barrels of the RAD-SOK terminal are made from copper dueto its’ high electrical and thermal conductiv-ity.
HOLDERS
Depending on the customer specificationsand manufacturing process, the terminalholder is made from copper or copper alloy.If the holder is turned on a CNC lathe orScrew Machine, Tellurium copper is usedbecause of its machining ability. Impact ex-trusions or stampings can benefit from cop-per’s ductility and therefore CDA110 orequivalent is typically used. Brass is com-monly used in electrical terminals, which donot require a high level of conductivity, and360 Brass is usually specified for RAD-SOK components.
The RADSOK cartridge is typically press-fit into the holder, which provides an elec-tromechanical means of terminating thecartridge. This termination may be via athreaded fastener, a finger grip, or a wirebarrel for crimping to wire. Copper is thebest material with respect to electrical con-ductivity, however it is more expensive thanother available materials such as brass andmay not be required to achieve the designobjectives of a given application. Copper isalso the best choice for metallic holdersthat incorporate wire barrel crimps. Copperis more ductile and is more formable thanbrass that is harder and tends to crack.
PLATINGPLATINGPLATINGPLATING
Plating involves depositing a layer of metalon the exterior surface of an object. Electri-cal terminals are generally plated to in-crease the terminal’s mechanical life, elec-trical properties and resistance to corrosion.
There are two methods of plating:
1. Electroplating
2. Electro-less Plating
Submersing an object in a chemical bathcalled electrolyte performs electroplating.The object to be plated is connected to anelectrode in the bath. Another electrodecomposed of the plating metal is also sub-mersed into the bath. Electrical current ispassed through the bath, causing platingmetal to deposit and adhere to the objectssurface. The electroplating method leavesthicker deposits on sharp exterior edges.For instance, if a copper plate were electro-plated with silver, the outer edges wouldhave a thicker deposit with the middle ofthe surface receiving a thinner depositTypically, the ratio of thickness betweenedge deposits and center deposits is ap-proximately 2 to 1. Care must be takenwhen plating blind holes. Electrical currentflowing through the electrolyte will not floweasily into the hole resulting in a thinner de-posit decreasing in thickness towards thebottom of the hole.
Electro-less plating is performed withoutan externally applied voltage to depositmetal. This method results in plating de-posits being more evenly deposited ontoirregular surfaces and into blind holes.Electro-less plating is normally a more ex-pensive process than electroplating.
PLATING THICKNESS
Plating thickness should be sufficient toachieve the desired operational parametersof a product. Because all metals are po-rous to some degree, metal deposits shouldbe thick enough to minimize the porosity ofthe plating deposit. When plating an elec-trical terminal, the projected mechanicalwear (insertion/extraction) and the conduc-tivity required in the terminal applicationshould be considered when determining theplating material.
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PLATING MATERIALS
Table 3 includes several metals used forelectrodeposits with some of their proper-ties listed in decreasing order of electricalproperties.
Typically, and depending on the applicationand environment, RADSOK terminals areplated with silver or tin. The plating usesand benefits follow.
Silver is a general purpose plating fre-quently used when the electrical terminalsmust carry high voltage with low conductiveloss. It can be noted in Table 3, that silverprovides the best electrical and thermalproperties of all available plating metals.Silver forms a surface film of sulfide whenexposed to a sulfide atmosphere, but istypically broken down when high currentsare passed through. Surfaces can be pro-tected from tarnish by applying a chromatecoating, which has minimal effects on con-tact resistance.
Tin is a frequently used plating material forRADSOK terminals when the connectionis not subject to a considerable amount ofmechanical cycling or vibration. Tin is vul-nerable to a phenomenon called frettingcorrosion. When exposed to air, tin rapidlyoxidizes. Minute movement between con-tact surfaces can expose a plated surfaceto air. When tin plating is exposed to air, tinoxide forms. Tin oxide is brittle, and whenmore movement occurs, the oxide is frac-tured further exposing the plated surface to
air. This process may repeat over time andcan lead to plating failure. Application oflubrication to the contact surfaces can re-duce the occurrence of fretting corrosionfrom occurring. Due to its high ductility, tinplating is a good choice for metal parts thatwill be bent or formed after plating. Tinplating can also be used to eliminate gal-vanic couples between dissimilar metals.Rapid plating deterioration will also occur iftin plated contacts are allowed to arc or iftemperatures exceed 100C.
Nickel can be deposited by electroplateand electro-less methods. Nickel is typi-cally used as an under plate for preciousmetal deposits such as silver. Copper as abase metal tends to migrate through metalsplated on its surface. Nickel provides a mi-gration barrier to the copper. Electro-lessnickel-phosphorous must be avoided as aplate metal due to its high resistance. Asthe phosphorus content of the plating solu-tion increases, so does the electrical resis-tance. Electro-less nickel-boron is accept-able, however it is a more expensive mate-rial than nickel-phosphorous.
HIGH TEMPERATURE EFFECTS on HIGH TEMPERATURE EFFECTS on HIGH TEMPERATURE EFFECTS on HIGH TEMPERATURE EFFECTS on THE RADSOK® TERMINALTHE RADSOK® TERMINALTHE RADSOK® TERMINALTHE RADSOK® TERMINAL
When copper and copper alloys are usedas spring members, like the grid of theRADSOK terminal, attention must be paidto a mechanical property known as stressrelaxation. When spring copper, such asthe beryllium copper of the RADSOK ter-minal, is subjected to high temperaturesdue to environment, electrical heating or acombination of the two for extended periodsof time, some stress relaxation may occur.
The inserted pin in the RADSOK terminalimparts a spring like stress as it opens thegrid. This stress is necessary for the RAD-SOK to function properly. When hightemperature is involved, over time, thespring elements may decrease or relax.
Electro-deposits
Electricalresistance(µµµµΩΩΩΩ/cm)
ThermalConduct-ivity,%Ag
Silver (Ag) 1.59 100.0Copper (Cu) 1.692 91.8Gold (Au) 2.44 70.0Nickel (Ni) 7.8 14.2Tin (Sn) 11.5 15.5Table: Plating Metal Material Properties
15
Stress relaxation is a function of tempera-ture and time. The effect of high tempera-ture exposure for extended time periodswhen the RADSOK grid is stressed frompin insertion is additive. The result of thetwo factors can be predicted through theuse of Larson-Miller parameters. This is agraphical approach shown in figure 12.
To determine stress relaxation resistance:
1. Choose accumulated exposure time onright-hand axis of the graph.
2. Draw a horizontal line from the time de-termined above to the appropriate tem-perature line (indicated on top ofgraph).
3. Draw a vertical line from the point de-termined in 2 to the stress relaxationcurve.
4. From the point of intersection on thestress relaxation curve determined in 3,draw a horizontal line to the left-handside of the scale and read the value ofremaining stress.
It is recommended to keep the RADSOKterminals extended heat exposure below120°C (248°F) for maximum life. Some ap-plications may involve higher operatingtemperatures. Given the temperature and
the continuous time at that exposure, theremaining stress in the grid can be pre-dicted using the Larson-Miller parameters.The remaining stress should be greaterthan 80 percent for the desired time-temperature exposure.
It is not recommended that RADSOK® termi-nals be soldered, welded or brazed to cableor other conducting bodies. If it is abso-lutely necessary, measures must be taken tokeep the RADSOK® terminal as cool as pos-sible to minimize stress relaxation.
This manual provides additional dimensionsto aid manufacturing cartridge holders andpin specification development. For customapplications, KONNEKTECH offers a com-plete in-house terminal development andprototyping department. Applications re-quiring quick connect or disconnect withhigh current flow. The two basic types ofterminal configurations are in-line and 90°.These configurations refer to how the axisof the pin and the cable are oriented.
CRIMPING of RADSOK® TERMINALSCRIMPING of RADSOK® TERMINALSCRIMPING of RADSOK® TERMINALSCRIMPING of RADSOK® TERMINALS
Crimping of the RADSOK terminal is animportant element of the electrical connec-tion. KONNEKTECH will provide a completeassembly to customers if required. For cus-tomers that desire to produce their own as-semblies, crimping guidelines for RAD-SOK terminals have been prepared.
Carefully select an appropriate electricalcable. The cable should be rated to carrythe required current on a continuous basisat a specified resulting temperature basedon the cable’s insulating material. The ca-ble should be properly sized for the applica-tion and electrical contact being used.Some welding cable is manufactured withthe insulating jacket material actuallybonded to the conductor strands. This type
Figure 12: Larson-Miller Plot
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of cable is intended for other applicationsand should not be used with RADSOKterminals Cables with a 600 volt UL ratingor better are recommended.
Stripping of Cable
First, cleanly and squarely cut the end ofthe cable being stripped. Next strip theInsulating jacket from the end of the wire,allowing for approximately a 2mm assemblyclearance. Care should be taken to ensurethe bundled copper strands comprising theconductor remain intact during the jacketstripping process. See Figure 13. Notmore than 10% strand loss is usually per-mitted.
Cable Inspection
After stripping, visually inspect the conduc-tor for signs of contaminants. The strippedcable must be free from insulating materialand have a shiny metallic appearance, freeof oxides. Oxides on the conductor will in-crease the electrical resistance of thecrimp, resulting in heat generation at thecrimp.
Terminal Crimping
For optimum electrical performance, insertthe stripped cable to the full depth of thewire barrel, taking care that all conductorstrands are inserted. Make the crimp in thewire barrel area, close to the opening. Thecrimp length should be short of the wire
barrel depth by about 2 millimeters. Crimp-ing beyond this depth can result in a poorlycrimped connection and may result in barrelcracking.
NOTE:NOTE:NOTE:NOTE: Soldering or Welding of the RADSOK®cartridge is not recommended! If solderingor welding cannot be avoided, care must betaken to keep the RADSOK® cartridgetemperature as low as possible to avoid“spring (stress) relaxation” damage.
Crimping Tools
There are many types of crimp tools. Onlyuse tools specifically designed to crimpelectrical connectors. Tools used for crimp-ing should also be appropriate for a givenwire barrel size. Hand operated crimp toolsare available from the following sources:
Anderson Products Division of Square DP.O. Box 455Leeds, Alabama 35094Phone: (205) 699-2411Fax: (205) 699-7603
Burndy CorporationU.S. Electrical DivisionCustomer Service Department101 E. Industrial Park DriveManchester, New Hampshire 03109Phone: (800) 346-4175
Model VC6-3 Versa-Crimp hydraulic handoperated compression tool with typeVCHTG Direct Reading Pressure Gauge byAnderson Products is currently being quali-fied for crimping RADSOK terminals.
Hex crimps can be provided by KONNEK-TECH on a variety of barrel crimps up to 2/0cabling. KONNEKTECH can also developtooling for customers who desire to crimptheir own products.
Figure 13: Barrel Crimp Cross-Section
17
APPENDIXAPPENDIXAPPENDIXAPPENDIX
Dimensions of RADSOK® Cartridge and Pin
C O N T A C T PIN R A D SO K ® C A R T R ID G E(R eceptacle)
SIZE (m m ) D iam eter A Pin Function Length1 D iam eter B Length6.0 6.0 (0.236”) 21.84 (0.860”) 9.53 (0.375”) 21.84 (0.860”)8.0 8.0 (0.315”) 25.65 (1.010”) 13.49 (0.531”) 25.65 (1.010”)
Notes: 1. The functional length does not include the male pin end radius.2. Radius should be at least 1.0 mm.3. The center ½ of the RADSOK® grid legs comprise the “functional length”
of the cartridge.
Recommended RADSOK® Press-Fit Assembly Procedure
The following should be used as a guide for the purpose of assembling RADSOK® car-tridges into connector bodies. The information contained herein provides recommendedpress-fit and terminal pin dimensions for optimum mating and electrical performance.
1. RADSOK® holder or sleeve should have a slight lead-in chamfer for ease of assembly.
2. Size of the cavity should have 0.025 to 0.076 mm(0.001 to 0.003”) interference fit with respect to theoutside diameter of the RADSOK® cartridge.
3. Use a square machine vice or arbor press for pressingRADSOK® cartridge into holder.
4. DO NOT use a hammer to install RADSOK® cartridgeinto holder.
18
5. Dimension “D”, the holder outer diameter, should be determined considering allowabletemperature rise for desired electrical current and metal being used. The interference fitshould be decreased within the 0.025 mm (0.001”) to 0.076 mm (0.003”) range as wallthickness increases.
6. The RADSOK® cartridge should be pressed far enough into the holder so that thecenter seam of the cartridge (see figure above) is buried by 3.0 mm if possible.
RADSOK PRESS-FIT ASSEMBLY INFORMATIONRADSOK Terminal RADSOK Holder Press Fit Dimensions
Size, mm Dimension C+0.00/-0.025 mm +0.000/-0.001 in.
6.0 9.50 0.3748.0 13.44 0.529
10.3 16.99 0.66814.0 17.42 0.868
19
60°C
75°C
90°C
AW
Gin
ches
mils
mm
in2
circ
.mils
mm
2in
ches
mm
(140
°F)
(167
°F)
(194
°F)
80.
1285
128.
53.
264
0.01
316
,510
8.37
0.16
24.
115
6070
80
70.
1443
144.
33.
655
0.01
620
,820
10.5
50.
196
4.97
8
60.
1620
162.
04.
115
0.02
126
,240
13.3
00.
215
5.46
180
9510
5
50.
1819
181.
94.
620
0.02
633
,090
16.7
70.
240
6.09
6
40.
2043
204.
35.
189
0.03
341
,740
21.1
50.
269
6.83
310
512
514
0
30.
2294
229.
45.
827
0.04
152
,620
26.6
70.
305
7.74
712
014
516
5
20.
2576
257.
66.
543
0.05
266
,360
33.6
20.
337
8.56
014
017
019
0
10.
2893
289.
37.
348
0.06
683
,690
42.4
10.
376
9.55
016
519
522
0
1/0
0.32
4932
4.9
8.25
20.
083
105,
600
53.4
90.
423
10.7
4419
523
026
0
2/0
0.36
4836
4.8
9.26
60.
105
133,
100
67.4
30.
508
12.9
0322
526
530
0
3/0
0.40
9640
9.6
10.4
000.
132
167,
800
85.0
10.
576
14.6
3026
031
035
0
4/0
0.46
0046
0.0
11.6
800.
166
211,
600
107.
220.
645
16.3
8330
036
040
5
250M
CM
0.50
0650
0.6
12.7
160.
196
250,
000
126.
770.
880
22.3
5051
0
300M
CM
0.54
7754
7.7
13.9
120.
236
300,
000
152.
01
350M
CM
0.59
1059
1.0
15.0
120.
275
350,
000
177.
351.
010
25.4
6063
8
*SIN
GLE
INS
ULA
TE
DC
ON
DU
CT
OR
SIN
FR
EE
AIR
-A
MB
IEN
TT
EM
PE
RA
TU
RE
OF
30°C
(85°
F)
RA
DS
OK
®A
MP
AC
ITY
CH
AR
T
14.0
mm
RA
DS
OK
®
(154
mm
2 )
3.6m
mR
AD
SO
K®
(10.
2m
m2 )
AM
PE
RE
SP
ER
CO
ND
UC
TO
R*
SO
LID
BA
RE
CO
PP
ER
WIR
ES
Dia
met
erC
ross
Sec
tiona
lAre
aN
omin
alD
ia.
ST
RA
ND
ED
FL
EX
CA
BL
E(C
lass
M)
The
3.6m
mR
AD
SO
K®
may
also
beus
edw
ith#7
or#6
depe
ndin
gup
onth
eap
plic
atio
n.
The
6.0m
mR
AD
SO
K®
may
also
beus
edw
ith#4
or#3
depe
ndin
gup
onth
eap
plic
atio
n.
Sm
alle
rw
iresi
zes
are
also
com
patib
lew
ithth
e3.
6mm
RA
DS
OK
®.
The
8.0m
mR
AD
SO
K®
may
also
beus
edw
ith1/
0de
pend
ing
upon
the
appl
icat
ion.
The
10.3
mm
RA
DS
OK
®m
ayal
sobe
used
with
4/0
depe
ndin
gup
onth
eap
plic
atio
n.
8.0m
mR
AD
SO
K®
(50.
3m
m2 )
10.3
mm
RA
DS
OK
®
(83.
3m
m2 )
6.0m
mR
AD
SO
K®
(28.
3m
m2 )
20
RADSOK® PERFORMANCE DATARADSOK® PERFORMANCE DATARADSOK® PERFORMANCE DATARADSOK® PERFORMANCE DATA
Temperature Rise of 14.0 mm RADSOK Terminal in Free Air
0
5
10
15
20
25
30
35
40
45
50
250 270 290 310 330 350 370 390 410
Amperage (A)
Tem
per
atu
reR
ise
(°C
)
Terminals attached to #4/0AWG CableAmbient Temperature: 25°C
Effect of Lubrication - 10.3mm w/ Ag Plating
0
1
2
3
4
5
6
1 2 3 4 5 6 7 8 9 10
Insertion Cycle #
Po
un
ds
f
Force w/Lube
Force w/o lube
INSERTION FORCE WITH & WITHOUT LUBRICATIONINSERTION FORCE WITH & WITHOUT LUBRICATIONINSERTION FORCE WITH & WITHOUT LUBRICATIONINSERTION FORCE WITH & WITHOUT LUBRICATION
21
TEMPERATURE RISE DATA TEMPERATURE RISE DATA TEMPERATURE RISE DATA TEMPERATURE RISE DATA ---- CURRENT OVER TIME CURRENT OVER TIME CURRENT OVER TIME CURRENT OVER TIME
0
20
40
60
80
100
120
0 10 20 30 40 50 60
Time (minutes)
400A
100A
100A
100A
175A
150A
200A
200A
250A
300A
325A
250A
300A
375A
450A10.3mm RADSOK® Data in BLUE
8.0mm RADSOK® Data in GREEN
6.0mm RADSOK® Data in RED
22
0
10
20
30
40
50
60
70
140 160 180 200 220 242
RADSOK T-Rise Split Pin T-Rise
TEMPERATURE RISE DATA TEMPERATURE RISE DATA TEMPERATURE RISE DATA TEMPERATURE RISE DATA ---- RADSOK® vs. Split Pin Terminal RADSOK® vs. Split Pin Terminal RADSOK® vs. Split Pin Terminal RADSOK® vs. Split Pin Terminal
Optimum 6.0 mm RADSOK Configuration
0
50
100
150
200
250
Degree of Twist
0
2
4
6
8
10
12
14
16
18
10 20 30 40 50 60 70 80
Resistance (micro-ohms) Insertion Force (lbs.)
23
ANOVA - CombinedOutputs
10.3mm Sn PlatedRADSOK
PINFINISH
24%
GRIDTWIST
43%
PINDIAMETE
R8%
MATINGCYCLES
21%
ERROR4%
2.50 2.75 3.00 3.25 3.50
0
5
10
15
20
Histogram-TwistControl w/oPlating
Microvolt Drop/Amp vs. Insertion Force - Initial
0
100
200
300
400
500
600
700
0 1 2 3 4 5 6 7 8 9 10 11
Insertion Force (#)
10.3mm, Tin Plated RADSOK with Tin Plated Pin, Measured Across 9" 2/0 cable + crimp +RADSOK + crimp + 9" 2/0 cable
