1705 best practices of wire harness manufacturing

Best Practices of Wire Harness Manufacturing

www.sunelecsys.com 913-894-1442www.sunelecsys.com 913-894-1442

Agenda

➢Topic: Building wire and cable harnesses

➢ Basic considerations of the best industry practices

➢Discussion on the total cost of ownership of wire harness manufacturing


“Best Practice”Best Practice – “a procedure that has been shown by research and experience to produce optimal results and that is established or proposed as a standard suitable for widespread adoption ”

• Not a fixed rule

• Not a standard

• Refer to manufacturer’s recommendations

• Refer to standards or procedures required by the organization


IPC/WHMA-A-620Requirements and Acceptance for Cable and Wire Harness Assemblies

• Developed in cooperation with Wire Harness Manufacturer’s Association® and IPC

• Most recent version: IPC/WHMA-A-620C

• Materials, methods, tests, and acceptability criteria


Other Standards & Certifications• UL

• Establish traceability

• In accordance with a harness diagram furnished by the end-use manufacturer

• Generally designed for a specific application

• Government

• Private organizations


PreparationCutting and Stripping

• Automated machines – programable• Wire characteristics• Length• Memory

• Manual• Small lots, prototypes


PreparationCutting and Stripping• Cut length

• Tolerance• Accuracy• Consistency

• Strip length• Terminal manufacturer

recommendation• Tolerance • Accuracy• Consistency


PreparationCutting and Stripping

• Proper stripping methods and tools• Eliminate, minimize strand damage

• Some strand damage allowed• TARGET

• Perpendicular to access• All the same length• No damage


PreparationWire Insulation Damage

• Acceptable• Slight uniform impression from

stripper for gripping• Fraying should be agreed upon

• TARGET• Trimmed neatly• No pinching, pulling, fraying,

discoloration, charring or burning

• Defect• Cuts, breaks, cracks, splits• Reduce insulation thickness• Uneven or ragged pieces of

insulation

Image credit: Carson Dunlop; Zeus Inc.


Crimp Terminations• Most common method of

harness terminations

• Improper terminations:• Opens

• Shorts

• False Positive

• Equipment failure

• Many options


Crimp TerminationsCrimp tools

• Manual• Small number of crimps• Simple

• Powered• Lugs• Electric, hydraulic high pressure

• Small production lots

• Larger wire, high pressure

• Terminals• Large production lots

• Highly automated

• Precision, repeatability


Crimp TerminationsBasic Requirements

• Correct wire

• Correct terminal

• Proper wire preparation

• Correct tooling

• Proper equipment calibration and set up

• Proper training


Crimp TerminationsPowered Crimp Tools

• Highly automated

• High quality, repeatability

• Adjustable speed

• Terminals on reels

• Easy to use, change-over

• Multiple terminals and variations


Crimp TerminationsManual Crimp Tools

• Matched tool and die• Proper crimp for chosen

terminal and wire

• Ratcheting feature• Will not release until

proper crimp is executed• Uniform crimp

terminations

• Adjustable and calibrated


Crimp TerminationsProper Crimping



• Conductor crimp• Mechanical compression of the metal terminal around the wire conductor

• Continuous conductive electrical path

• Conductor brush• Wire strands past the conductor crimp

• Ensures mechanical compression over the full length of the crimp (strip length)

• NOT extend into contact area

• Insulation crimp• Strain relief

• Hold insulation as firmly as possible without cutting into conductor strands




Crimp TerminationsCrimp Defects

• Causes• Incorrect tool, set up, or calibration

• Incorrect wire preparation

• Strip length• Too short, not fully inserted – weak mechanical and electrical performance

• Inserted too far – weak mechanical and electrical performance

• Loose wire strands• Reduced electrical performance

• Potential short circuit or arc to other contact

• Reduced mechanical performance

• Crimp height• Too high – Poor compression, voids – weak mechanical and electrical performance

• Too low – Cut, fracture conductor wire – weak mechanical and electrical performance


Crimp TerminationsCrimp Defects


Crimp TerminationsProcess Verification

• Pull test• Correct crimp tool for terminal, wire

• Calibration of crimp tool

• Verify crimp – adjust process, tooling

• Preproduction test• Destructive

../../../../../Customers/XAlt/XP-102910/PO 40319/2016-08-01 17.03.44.mov


Crimp TerminationsProcess Verification

• Crimp height• Correct crimp tool for terminal, wire

• Calibration of crimp tool

• Verify crimp – adjust process, tooling

• Preproduction AND process control• Non-destructive


Precision cut

Precision strip

Manufacturer’s recommended crimp

Crimp height verification

Continuity-tested, assembled harness

Best PracticesIdeal Process for Consistency


Other Processes •Twisting of wire

•Soldered terminations

•Ultrasonic welding

•Splices

•Over-molding

•Potting

•Connectorization

•Assembly and wire measurement

•Marking and labeling

•Securing

•Shielding

•Protective coverings

•Testing


Total Cost of Ownership• How to respond to market demand quickly while enabling

business objectives?

• What is the best use of your limited resources?

• Wouldn’t you prefer to concentrate on your core business?

• Where else can your reduce or eliminate overhead?

• Is there an opportunity for improvement in your supply chain or production processes?

• How can you manage overall corporate risk?

• How do you remove the bottleneck in your supply chain?


Total Cost of OwnershipPrimary cost factors

•Materials

•Labor

•Delivery

0%

20%

40%

60%

80%

100%

Facility Overhead

Labor

Material

Other

AX

IS T

ITLE

AXIS TITLE

Automobile Wire Harness Cost Components

Graph credit: Ask, Laseter.


Total Cost of OwnershipMaterials

• Cost of materials• Best price?• Not only driver

• Inventory• Multiple vs. individual?• Space constraints?• Excessive?• Slow/Non-moving?

• Equipment and tooling• Cost?• Variations?


Total Cost of OwnershipLabor

• Processing• Consistency?

• Optimal utilization?

• Inventory• Simplify ordering?

• Management?

• Receiving?

• Equipment• Maintenance?

• Calibration?


Total Cost of OwnershipDelivery

• Quality

• Cost• International?

• Domestic• Low run, prototyping?• Reduced lead time?• Simplify?

• Customized• Kitting?• Fast-track projects?


Questions?Sunflower Electrical Systems

8302 Hedge Lane Terrace, Suite H, Shawnee, KS 66227

+1-913-894-1442 [email protected]

Follow us on:


Sources• Ask, Julie A. and Laseter, T. (1998, January). Cost Modeling: A Foundation Purchasing Skill.

Strategy + Business. Retrieved from https://www.strategy-business.com/article/9625?gko=ba075.

• best practice. (2017). In Merriam-Webster.com. Retrieved May 16, 2017, from https://www.merriam-webster.com/dictionary/best%20practice.

• General Motors Upfitter Integration. (2017). Electrical Best Practices. Retrieved from https://www.gmupfitter.com/publicat/electrical.pdf.

• IPC. The Seven Sins of Wire Harness Assembly (DVD-60C Script). Retrieved from http://www.ipctraining.org/dvd/60c/script.pdf.

• IPC and Wire Harness Manufacturer’s Association. (2012). Requirements and Acceptance for Cable and Wire Harness Assemblies (IPC/WHMA-A-620B).

• Molex, LLC. (2017). Hand Crimp Tool Specification Sheet, Order No. 63811-6000, Doc. No. ATS-638116000, Revision: E. Retrieved from http://www.molex.com/pdm_docs/ats/ATS-638116000.pdf.

• National Aeronautics and Space Administration. (2017). Crimping, Interconnecting Cables, Harnesses, And Wiring – National Technical Standard. Retrieved from https://prod.nais.nasa.gov/eps/eps_data/145968-OTHER-002-006.pdf.

• Sarkar, S. (2017, May). Successful revolutions need suppliers. ISE Magazine, 34-39.

https://www.strategy-business.com/article/9625?gko=ba075

https://www.merriam-webster.com/dictionary/best practice

https://www.gmupfitter.com/publicat/electrical.pdf

http://www.ipctraining.org/dvd/60c/script.pdf

http://www.molex.com/pdm_docs/ats/ATS-638116000.pdf

https://prod.nais.nasa.gov/eps/eps_data/145968-OTHER-002-006.pdf

Technology

1705 best practices of wire harness manufacturing