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Trouble shooting and Tips and Tricks

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  • Trouble shooting and Tips and Tricks

    Thread Tape:

    Well, one of the reasons one of the machines I am working on, is the leaks in the system ??

    Guess what; THREAD tape every where and lots of it....  Like bunches of grapes and soft fluffy pillows on every fitting, along with signs of leaking and crap oozing out.

    A: Most of it has ended up being pushed off the thread and thus nothing more that a lump of ptfe trying to act as an external washer  

    B: Also some bits in one solenoid..

    Application Instructions for PTFE Pipe Thread Sealing TapePlace end of tape on pipe thread 1/8” from end of pipe.

    1. Wrap tape around pipe with 70% overlap = 3 layers all the way around the malethread. Stretch tape enough to pull into the thread without causing the threadtape to shred. Overlap back to the starting point.

    2. Press tightly on tape and break it. Pipe thread is now ready for joining.

    3. Joint should be tightened according to the fitting or device manufacturers’ specifications.  

    NEVER USE PTFE PIPE THREAD SEALING TAPE ANDPASTE TOGETHER.Seal integrity will depend on the quality of the male and female thread, fluidpressure, and the nature of fluid being sealed. The 70% overlap is acceptable undernormal water use with fixtures in normal repeated use condition. Higher riskapplications may require greater overlap or the use of high density thread sealingtape.


    NOTE:  In the trade we were also taught that it goes on, so that when tightening the joints, it does not catch and push the tape off and into a bunch...

    Hold the end of the tape flat against the pipe threads, flush with the end of the pipe, then turn the pipe clockwise, or as though you were tightening it ( R/H or L/H thread makes a difference.) .

    Put 1-1/2 to 2 turns of tape on the pipe, keeping the tape flat and tight against the pipe as you turn, and overlap as per above.

    The reason for doing it this way is so the loose end gets pinned down by the action of screwing the pipe in, rather than getting flipped up and pushed off.

    Same for when doing the tape mods to Rocky grinders.

    WiKi - Over-use, or mis-application of thread tape may be a hazard. As the tape material is so soft, excess or overhangs may easily break off and form a foreign body contaminant that could jam a valve seat etc.

    OH so true....

  • #2
    Re: Trouble shooting and Tips and Tricks

    An engineering approach for troubleshooting:

    Troubleshooters call a "Split Half Search" or a "Binary Search" which deal explicitly with the division between quick fix and systematic diagnosis and root cause discovery. ... (Then they decided to call it Quality and define it in a standard and now its someone elses problem);

    What complicates this is the Assumptions one makes and or the Lack of information and or detail provided. In addition and experienced person uses most if not all of their senses when working on a problem and if not hands on; they can be significantly compromised due to lack of feedback and sensory input. As has been said before; A picture can tell a 1000 words and add to that the loss of hearing / touch and smell and the troubleshooter is grossly handicapped. .

    Split-Half Search:

    A split-half search / binary division; is a technique for systematically isolating the source of an issue. You start by eliminating roughly half of the items you are checking, then trying to re-create the issue / find which half the fault is in. You continue halving your search group until you find the source of the issue.

    A split-half search requires applying knowledge of the product, its common issues, and the symptoms as you check one possible cause after another, in a logical order. This part of the troubleshooting process can be the most difficult and the most time-consuming. Thats why a logical and methodical plan is so important.

    First split - User Vs Hardware

    User errors: PEBFAG - Check for user errors in the course of gathering information, and trying quick fixes. But keep in mind the possibility of incorrectly set switches or preferences, incompatible equipment, and incorrect assumptions on the users part; take nothing for granted.

    But how often do users / posters get touchy when one tries to confirm and or they dont provide teh information asked for ? managing this by text; can be daunting and fraught with danger

    Software-related issues: Software that is unusable or that doesnt work with other software, viruses, extension conflicts, and mass of other software issues can cause symptoms that may look like hardware issues.

    A minor distraction for most of us with coffee machines but data logging software can be an issue.

    Second Split:

    Hardware issues. When you are convinced that user error/software, a is not the cause of the issue, hardware is what is left.

    Simplify the issue. Find the “problem space” in the hardware. Try to identify the functional area that the issue affects and again split the problem.

    Electrics Vs Plumbing etc

    Thus one then splits and works through the functional blocks untill the problem is isolated; at which stage a solution can be applied.


    Note: All of this takes time and relies on the user providing good data and feedback if the person troubleshooting in not on site.

    The other issue is that there are some many variables in the raw product and preparation; that all so often, a poor shot still comes back to - PEBFAG.


    • #3
      Re: Trouble shooting and Tips and Tricks

      The problem for Trouble shooters:

      Troubleshooting for diagnostics.

      Engineers in the service function are often focused on troubleshooting as in "(a) hunting for or locating causes of malfunctions and (b) acting to eliminate or clear them. It includes both locating and clearing." For any particular system, one or the other may be more important.

      Existence of Expert Performance.

      FAQs etc are more than just a collection of features (that is, questions) and solutions (that is, answers). They can often describe an approach to solving problems. Often, there are people who solve problems significantly better than others. It is this expertise "best thinking
      practices" - that FAQs and forums seek to capture and distribute to others.

      Experts Have a Hard Time Describing What They Know.

      Often, experts are willing to share their knowledge, if for no other reason than to reduce their work load.

      However, it is often hard to get this knowledge out of our/their heads, especially as logic gets complex. Perhaps they have compiled years of experience so that they can make leaps in their reasoning; that others cannot.

      Experts Have a Hard Time With Generalisations.

      Thus we often experience a clash between real world experts and those that found a post on Google. Further more that leap in reasoning (see above) may be so convoluted that it is neigh on impossible to explain in detail. Thus while generalisations may be used they are just that and the devil is in the detail.. The mistake is where detail is used to refute a generalisation or a generalisation is accepted as 100% correct; generalisations are just that and nothing more.


      • #4
        Re: Trouble shooting and Tips and Tricks

        The basics about Electricity and some good tips..

        Also for those who might think an ELCB will save them... They will not always!!!

        ELCBs have some disadvantages:

        They do not detect faults that dont pass current through the CPC to the earth rod.
        They do not allow a single building system to be easily split into multiple sections with independent fault protection, because earthing systems are usually bonded to pipework.

        They may be tripped by external voltages from something connected to the earthing system such as metal pipes, a TN-S earth or a TN-C-S combined neutral and earth.
        As with RCDs, electrically leaky appliances such as some water heaters, washing machines and cookers may cause the ELCB to trip.

        ELCBs introduce additional resistance and an additional point of failure into the earthing system.

        Earth bypassing

        It is not unusual for ELCB protected installation to have a second unintentional connection to earth somewhere, one that does not pass through the ELCB sense coil. This can occur via metal pipework in contact with the ground, metal structural framework, outdoor home appliances in contact with soil, and so on.

        When this occurs, fault current may pass to earth (VIA YOU) without being sensed by the ELCB. Despite this, perhaps counterintuitively, the operation of the ELCB is not compromised. The purpose of the ELCB is to prevent earthed metalwork rising to a dangerous voltage during fault conditions, and the ELCB continues to do this just the same, the ELCB will still cut the power at the same CPC voltage level. (The difference is that higher fault current is then needed to reach this voltage.)

        Nuisance trips

        While voltage and current on the earth line is usually fault current from a live wire, this is not always the case, thus there are situations in which an ELCB can nuisance trip.
        When an installation has two connections to earth, a nearby high current lightning strike will cause a voltage gradient in the soil, presenting the ELCB sense coil with enough voltage to cause it to trip.

        If the installations earth rod is placed close to the earth rod of a neighbouring building, a high earth leakage current in the other building can raise the local ground potential and cause a voltage difference across the two earths, again tripping the ELCB. Close earth rods are unsuitable for ELCB use for this reason, but in real life such installations are sometimes encountered.

        Both RCDs and ELCBs are prone to nuisance trips from normal harmless earth leakage to some degree. On one hand ELCBs are on average older, and hence tend to have less well developed filtering against nuisance trips, and on the other hand ELCBs are inherently immune to some of the causes of false trips RCDs suffer, and are generally less sensitive than RCDs. In practice RCD nuisance trips are much more common.

        Another cause of nuisance tripping is due to accumulated or burden currents caused by items with lowered insulation resistance. This may occur due to older equipment, or equipment with heating elements, or even wiring in buildings in the tropics where prolonged damp and rain conditions can cause the insulation resistance to lower due to moisture tracking.

        If there is a 30 mA protective device in use and there is a 10mA burden from various sources then the unit will trip at 20 mA. The individual items may each be electrically safe but a large number of small burden currents accumulates and reduces the tripping level. This was more a problem in past installations where multiple circuits were protected by a single ELCB.

        Heating elements of the tubular form are filled with a very fine powder that can absorb moisture if the element has not be used for some time. In the tropics, this may occur, for example if a clothes drier has not been used for a year or a large water boiler used for coffee etc has been in storage. In such cases, if the unit is allowed to power up without RCD protection then it will normally dry out and successfully pass inspection. This type of problem can be seen even with brand new equipment.

        HOWEVER - If it actually does have a fault... Unless you know what your doing.. YOUR DEAD


        • #5
          Re: Trouble shooting and Tips and Tricks

          My machine keeps tripping the ELCB when the heating comes on - how do I check the element ?

          Call an electrician.....

          Now to help you understand.. Here is a small pic.