In-Process Pull Test - UL-486 or EIA-364-38?

Z

zekeQA

#1
I am going to give a lot of detail so that we can focus on solutions, and not a lot of questions.

I am new to this very small manufacturing company, hired as quality manager to help with ISO9001 compliance. I am certified ISO9000 internal auditor and working towards a six sigma green belt. This company has no real procedures or controls of anything.

My customer asked for a corrective action on what they classify as a severe failure...a ten guage wire with an attached ferrule pulled out of a breaker in an electrical assembly. The ferrule did not pull off the wire, the ferrule pulled out of the breaker.

I have started a six sigma project of this failure and determined that the failure is associated with the torque force applied to the breaker wire clamp.

I was considering creating a procedure requiring the clamping screw to be torqued to manufacturer or drawing requirements.

I also considered measuring the ferrule clamping force to prevent any problems in that area....

However, my customer suggested that we create a technique to measure the pull force of the wire and ferrule in the breaker clamp. He suggested that we create our own guidelines... I don't want to do this because of the time and while I enjoy statistics I am not an expert... Also I want something that will be harder to refute than my experimentation.

Well, I know when I don't know something so I decided to look for a standard. UL-486 is expensive and I cannot get much information on EIA-364-38 which might work. My concern here is that most of these tests seem to be testing the pull force to remove the wire from the ferrule and I am concerned about the connection between the ferrule and the breaker.

I am reading an article and the author recommends against 100% in process pull testing, because of possible damage.

What I need is a suggestion on a standard, or a method, for inprocess electrical inspections of this connection.

:thanx:

zekeQA
 
Elsmar Forum Sponsor

Marc

Hunkered Down for the Duration with a Mask on...
Staff member
Admin
#2
If anyone here can help with this, you have my Thanks in advance!
 

Jim Wynne

Staff member
Admin
#3
I am going to give a lot of detail so that we can focus on solutions, and not a lot of questions.

I am new to this very small manufacturing company, hired as quality manager to help with ISO9001 compliance. I am certified ISO9000 internal auditor and working towards a six sigma green belt. This company has no real procedures or controls of anything.

My customer asked for a corrective action on what they classify as a severe failure...a ten guage wire with an attached ferrule pulled out of a breaker in an electrical assembly. The ferrule did not pull off the wire, the ferrule pulled out of the breaker.

I have started a six sigma project of this failure and determined that the failure is associated with the torque force applied to the breaker wire clamp.

I was considering creating a procedure requiring the clamping screw to be torqued to manufacturer or drawing requirements.

I also considered measuring the ferrule clamping force to prevent any problems in that area....

However, my customer suggested that we create a technique to measure the pull force of the wire and ferrule in the breaker clamp. He suggested that we create our own guidelines... I don't want to do this because of the time and while I enjoy statistics I am not an expert... Also I want something that will be harder to refute than my experimentation.

Well, I know when I don't know something so I decided to look for a standard. UL-486 is expensive and I cannot get much information on EIA-364-38 which might work. My concern here is that most of these tests seem to be testing the pull force to remove the wire from the ferrule and I am concerned about the connection between the ferrule and the breaker.

I am reading an article and the author recommends against 100% in process pull testing, because of possible damage.

What I need is a suggestion on a standard, or a method, for inprocess electrical inspections of this connection.

:thanx:

zekeQA
I know you didn't want questions, but...

Is there a specification from your customer regarding what pull force must be withstood?

You refer to both torque and pull--those are two different things (the former suggests rotation). Which are you concerned with? You need to know something about the forces the assembly is subjected to, and try to replicate those as closely as possible in your test method.
 
Z

zekeQA

#4
I know you didn't want questions, but...

Is there a specification from your customer regarding what pull force must be withstood?

You refer to both torque and pull--those are two different things (the former suggests rotation). Which are you concerned with? You need to know something about the forces the assembly is subjected to, and try to replicate those as closely as possible in your test method.

I really don't mind the questions...I just wanted to post enough information.

The customer has no requirement on pull force. They simple require the wire not to come loose again.

In regards to the torque vs. the pull, the torque on the screw is the specific technical requirement that keeps the wire from pulling out of the clamp.
 

Jim Wynne

Staff member
Admin
#5
I really don't mind the questions...I just wanted to post enough information.

The customer has no requirement on pull force. They simple require the wire not to come loose again.

In regards to the torque vs. the pull, the torque on the screw is the specific technical requirement that keeps the wire from pulling out of the clamp.
Without a specification, I don't know how you can devise a test. As it stands, if the customer attaches one end of the wire to the rear bumper of a Humvee and drives away and the ferrule comes out, the assembly has failed. You need to get the customer to commit to something before you start trying to do tests.
 
D

DrM2u

#6
Let's see if I got this right: in order for the breaker to work properly the force necessary to pull the wire apart from the ferrule must be less than the retaining force exercised by the breaker body onto the ferrule. In the failure reported by your customer the opposite happened.

It is my understanding that you are creating the bond between the ferrule and the wire by crimping the ferrule onto the wire. You can test the process (destructive testing on 50-100 parts should do) to establish the average retaining force and the standard deviation given certain crimping process parameters. A similar experiment should be performed to measure the average holding/retaining force between the reffurle and the breaker housing. Hopefully the second exceeds the first by a ratio of 1.5-2:1 (or the desired safety factor). Once you have this information then you can implement an in-process test inspection (destructive) to verify that the crimping process is still stable and in control. The same can be applied to the housing if you manufacture it.

Hope this makes sense and helps a little. :2cents:
 
R

ricevans

#7
You are battling a force called hysterisis, The torquing action of the screw onto the ferrule is countered by the spring tension placed on the ferrule. I battled this for many years and the only solution I ever found was to torque the wire in place (with or without ferrule the procedure is the same) wait 2 to 3 days and torque it again. It is also almost impossible to measure what a wire is torqued to once the effect has started. When we started doing this our incidence of loose wires decreased to a very manageable level.

Good luck.
 
Thread starter Similar threads Forum Replies Date
J Need Help with FPY Data in Assembly Process Manufacturing and Related Processes 7
A When someone refuses to follow a process.... Misc. Quality Assurance and Business Systems Related Topics 21
E Software maintenance Process Software maintenance Process to IEC 6204? IEC 62304 - Medical Device Software Life Cycle Processes 3
R AS5553 Clause 3.1.7 f - "Implement a returns process....." AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 5
normhowe "The Problem with Quality Management: Process orientation, controllability and zero-defect processes as modern myths" Book, Video, Blog and Web Site Reviews and Recommendations 2
Judy Abbott General temperature used in the blasting process and laser process Manufacturing and Related Processes 2
B SOP for CNC turret punching machine for sheet metal process Manufacturing and Related Processes 0
A API Monogram audit review process Oil and Gas Industry Standards and Regulations 4
R AS9102 FAI Change in Material / Process Supplier AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 4
A Process mapping Process Maps, Process Mapping and Turtle Diagrams 1
R MDEL Process Canada Medical Device Regulations 4
optomist1 Rates Daily or Hourly Process Improvement Training Consultants and Consulting 2
S Manufacturing Process FDA FOIA Medical Device and FDA Regulations and Standards News 3
S Manufacturing Process FDA FOIA US Food and Drug Administration (FDA) 4
B Toyota PPAP Process - Three Questions APQP and PPAP 3
R Changes vs CMO - How can we simplify this process? Supplier Quality Assurance and other Supplier Issues 3
A Ethics Committee Review Process for IVD Products EU Medical Device Regulations 2
V Laser Welding Process - Impact on Electrical Properties Reliability Analysis - Predictions, Testing and Standards 4
Q Process: Knowledge Section 7.1.6 of ISO 9001:2015 ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 10
L Documented Information in Internal Audits Process (9.2) ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 4
A Sampling plan for in-process QC (medical devices) Inspection, Prints (Drawings), Testing, Sampling and Related Topics 13
R MRB (Material Review Board) Process using MS Sharepoint or MS Teams Manufacturing and Related Processes 2
M Clinical Benefit of device that only aids in a process for managing or treating disease EU Medical Device Regulations 2
C In-process inspection - Tooling and assembly lines for automotive companies AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 6
M Efficacy of an IT process after a cyber attack ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 2
N Sterilization Protocol Change in Validation Process and further impacts ISO 13485:2016 - Medical Device Quality Management Systems 1
N Riveting - special process Manufacturing and Related Processes 11
M Material incoming to the production process reflected in PFMEA FMEA and Control Plans 9
A API Spec Q1 Purchasing Process - Supplier Reevaluation based on Supplier Risks 5.6.1.4 Oil and Gas Industry Standards and Regulations 17
B Handling lower detection limits for SPC and process performance Statistical Analysis Tools, Techniques and SPC 1
D Measurables for Plastic Injection molding process Manufacturing and Related Processes 1
S Cleaning process center change ISO 13485:2016 - Medical Device Quality Management Systems 4
Z Rapid audit template for plastic parts manufacturing process Manufacturing and Related Processes 12
R Inspection and Work order process Inspection, Prints (Drawings), Testing, Sampling and Related Topics 9
T ISO 13485:2016 Clauses related to process matrix ISO 13485:2016 - Medical Device Quality Management Systems 3
A How to reduce the process SPC monitoring Capability, Accuracy and Stability - Processes, Machines, etc. 3
John Predmore Configuration Management as a process instead of a procedure AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 10
R PCBA process validation Qualification and Validation (including 21 CFR Part 11) 2
U Internal Auditor not trained but done Audit for some process Nonconformance and Corrective Action 5
B Two excellent examples of process capability analysis from Quality Magazine Capability, Accuracy and Stability - Processes, Machines, etc. 5
D ECO (Engineering Change Order) process questions ISO 13485:2016 - Medical Device Quality Management Systems 7
S Sterilization validation after changing sterilization process provider Qualification and Validation (including 21 CFR Part 11) 3
Pau Calvo Quality Management process is mandatory in ISO9001? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 10
Tagin Template or Checklist for Process Change Document Control Systems, Procedures, Forms and Templates 5
LostLouie Manufacturer divorced from Design process, is he justified in design process deficiencies? ISO 13485:2016 - Medical Device Quality Management Systems 9
J 1.11 Preliminary Identification of Special Product and Process Characteristics APQP and PPAP 4
D Question regarding customer feedback process ISO 13485:2016 - Medical Device Quality Management Systems 3
T What does AS9100 mean when it says you must establish a process to do X? AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 24
J Process FMEA Template with examples - Cold and Hot Forged components FMEA and Control Plans 4
D Questions regarding process validation ISO 13485:2016 - Medical Device Quality Management Systems 6

Similar threads

Top Bottom