The IET is carrying out some important updates between 17-30 April and all of our websites will be view only. For more information, read this Announcement

This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Class 1 appliance with no exposed metal work to connect test lead too

Former Community Member
Former Community Member
Coffee machineOK 3rd problem class one appliance with no exposed metal work to connect test lead too how can I carry out the earth bond test given it is a class 1 appliance and not a class 2 appliance like this Coffee machine
  • 7bad1d11602a7f0b002f69c98d64154c-original-20201122_101529.jpg
  • ab6a924b9c218439d463499a065cdc4c-original-20201122_101600.jpg
  • deee3d5bd8cd30d441ad0b17bb2e31df-original-20201122_101901.jpg
  • So are you going to throw away the irons with unearthed metalwork on them or Teflon coated sole plates, because you cannot get a test result?
  • Former Community Member
    0 Former Community Member
    Sparkingchip:

    So are you going to throw away the irons with unearthed metalwork on them or Teflon coated sole plates, because you cannot get a test result?


    Ahh you see there in lies a problem if the sole plate is metal un earthed the body plastic and both basic and re-enforced insulation are used the item labeled class 2 even with an earth then its class 2 the problem with these coffee machines is the have no class two marking therefore must be treated as class one (as per the code of practice) but with no exposed metal work let alone earthed exposed metal work then surely they fail an earth bond test after all the test covers only parts a user may come into contact with during use (so any internal earthed metal work sufficiently protected by insulation requirements is therefore protected against contact by the user in the event of a fault developing meaning it can't be used as a eath bond test point due to the need to deconstruct the item to access it therefore it would invalidate any test results gained 


  • Former Community Member
    0 Former Community Member
    Sparkingchip:

    I recently stood in a Home in Multiple Occupation looking at a Teflon coated iron that needed PAT that had been purchased within the last year, since I last did the PAT, and entering onto the appliance log a copy of which had to be submitted to the Local Council Housing Team so the HMO licence could be renewed.


    So how do you PAT a virtually new Teflon coated iron?

    https://medium.com/@ironsexpert/steam-iron-soleplate-types-ceramic-stainless-titanium-62c60efefe7c


    Surely this would again depend on the construction class of the appliance as how it would be tested if no exposed earthed metal work is on the appliance but is not marked class 2 then must be treated as a class 1 appliance if it then fails said earth bond test then surely it must class as a fail, passing it is surely as bad as an overload circuit that keeps blowing fuses advice don't turn on to many things at once rather than solving the reason for the overloading occuring it's like putting a plaster over a gaping wound that requires stitching then saying it's fixed it's not done right the work must be completed to a high standard after all I take pride in my work and put my name to it if I don't feel something is safe I make it safe as possible to minimise risk then report it before continuing if something is of immediate danger then I will make it safe and remove from service before reporting as if it is wrong im responseable no different to any pat tester spark or other job where you take responsibility for your work as well as the health and safety of others throughout the work you do or the workplace you are in


  • So, you have a device with mains inside it. It may have a 2 core lead or 3.

    The over-arching principle is "double fault to danger" - no single failure of a wire off or a single layer of damaged insulation should put a user at risk.


    If there are conductive parts the user may hold these must not be live in operation, or able to become live in a single fault condition.


    Therefore exposed parts that are either solidly earthed, or well enough insulated from all 3 cores to hold off mains voltage (so if the earthed bits inside came live from a first fault it would not matter)


    So test L+N to CPC - should be high impedance. (no first fault)

    test CPC to exposed metal - if connected, impedance must be low enough to clear fuse on first fault.

    If not connected, retest at 500V  from CPC to exposed sufraces -  should be no connection, so if later there is a fault that makes the earthed bits inside live, you can be sure it will not reach the user, so you retain double fault to danger.


    It is important to recall that this Class 0, 0A ,1,2 3 business  is only  an arbitrary classification that is a convenience for grouping devices whose safety is assured in a particular way, so that the correct tests can be performed in order, and without too much thought.

    if you have something that does not  fit the classification, then like the chaps who dreamed it up, you need to think a bit about what you are trying to test and why. (in nature we have the odd platypus..)


    Of course any test is a snapshot on the day - if the user drops the thing in the sink or down the stairs and then it is dangerous, then that is their call, the tester is not liable for that.

    regards

    Mike.


  • Alex13:
    Sparkingchip:

    I recently stood in a Home in Multiple Occupation looking at a Teflon coated iron that needed PAT that had been purchased within the last year, since I last did the PAT, and entering onto the appliance log a copy of which had to be submitted to the Local Council Housing Team so the HMO licence could be renewed.


    So how do you PAT a virtually new Teflon coated iron?

    https://medium.com/@ironsexpert/steam-iron-soleplate-types-ceramic-stainless-titanium-62c60efefe7c


    Surely this would again depend on the construction class of the appliance as how it would be tested if no exposed earthed metal work is on the appliance but is not marked class 2 then must be treated as a class 1 appliance if it then fails said earth bond test then surely it must class as a fail, passing it is surely as bad as an overload circuit that keeps blowing fuses advice don't turn on to many things at once rather than solving the reason for the overloading occuring it's like putting a plaster over a gaping wound that requires stitching then saying it's fixed it's not done right the work must be completed to a high standard after all I take pride in my work and put my name to it if I don't feel something is safe I make it safe as possible to minimise risk then report it before continuing if something is of immediate danger then I will make it safe and remove from service before reporting as if it is wrong im responseable no different to any pat tester spark or other job where you take responsibility for your work as well as the health and safety of others throughout the work you do or the workplace you are in




    I think that's the wrong premise.


    I'll explain something first.


    If we are talking about a coffee machine, the exposed-conductive-parts in this instance may well be covered for a very good reason.


    The exposed-conductive-parts are likely to be a heating element. The heating element may well be connected to a metal boiler can - although this might be plastic.



    • In the former case, the exposed-conductive-parts are hidden to prevent electric shock (at the connector end of the element) and to prevent burn injury (metal can).

    • In the latter case, the exposed-conductive-parts are hidden to prevent electric shock (at the connector end of the element) ... and the plastic boiler container may also be shrouded to prevent burn injury,


    The product standard, or manufacturer's risk assessment, may well require some form of tamper-proof (not accessible to "ordinary persons") measures to prevent access to the connections end of the heating element, and the boiler can.


    Based on your deduction, would you also fail an electric shower because you can't get access to an exposed-conductive-part without dismantling or removing covers?



    Now, it's clear that someone who has the knowledge of this sort of appliance can test it. Someone who does not cannot.


    "Competence" in this instance, is knowing your limitations.
  • Former Community Member
    0 Former Community Member
    gkenyon:
    Alex13:
    Sparkingchip:

    I recently stood in a Home in Multiple Occupation looking at a Teflon coated iron that needed PAT that had been purchased within the last year, since I last did the PAT, and entering onto the appliance log a copy of which had to be submitted to the Local Council Housing Team so the HMO licence could be renewed.


    So how do you PAT a virtually new Teflon coated iron?

    https://medium.com/@ironsexpert/steam-iron-soleplate-types-ceramic-stainless-titanium-62c60efefe7c


    Surely this would again depend on the construction class of the appliance as how it would be tested if no exposed earthed metal work is on the appliance but is not marked class 2 then must be treated as a class 1 appliance if it then fails said earth bond test then surely it must class as a fail, passing it is surely as bad as an overload circuit that keeps blowing fuses advice don't turn on to many things at once rather than solving the reason for the overloading occuring it's like putting a plaster over a gaping wound that requires stitching then saying it's fixed it's not done right the work must be completed to a high standard after all I take pride in my work and put my name to it if I don't feel something is safe I make it safe as possible to minimise risk then report it before continuing if something is of immediate danger then I will make it safe and remove from service before reporting as if it is wrong im responseable no different to any pat tester spark or other job where you take responsibility for your work as well as the health and safety of others throughout the work you do or the workplace you are in




    I think that's the wrong premise.


    I'll explain something first.


    If we are talking about a coffee machine, the exposed-conductive-parts in this instance may well be covered for a very good reason.


    The exposed-conductive-parts are likely to be a heating element. The heating element may well be connected to a metal boiler can - although this might be plastic.



    • In the former case, the exposed-conductive-parts are hidden to prevent electric shock (at the connector end of the element) and to prevent burn injury (metal can).

    • In the latter case, the exposed-conductive-parts are hidden to prevent electric shock (at the connector end of the element) ... and the plastic boiler container may also be shrouded to prevent burn injury,


    The product standard, or manufacturer's risk assessment, may well require some form of tamper-proof (not accessible to "ordinary persons") measures to prevent access to the connections end of the heating element, and the boiler can.


    Based on your deduction, would you also fail an electric shower because you can't get access to an exposed-conductive-part without dismantling or removing covers?



    Now, it's clear that someone who has the knowledge of this sort of appliance can test it. Someone who does not cannot.


    "Competence" in this instance, is knowing your limitations.


    Thank you for your answer in such clear words and terms good point about the shower however they are like some fixed appliances not part of the scope of a pat test as the are directly connected to the fixed power supply system of the building and are rarely if ever supplied through a plug and socket configuration also they are more likely to be tested as part of a electrical installation safety test and inspection some fixed appliances that may pass through my hands can be fitted with a plug as part of installation (though may not always) can be pat tested other fixed appliances that are fitted through a fuse connection unit or switch connection unit can be pat tested however these are if installed best tested by an appropriate person (ie electrician) as part of the fixed installation safety assessment not a pat test and hence anything I either can't test shouldn't test or would be outside of the scope of my qualification and skill base (let alone legal allowance to do) would have to be noted un tested and needs to be checked by someone properly qualified and equipped which isn't me in some circumstances and accordingly I step back and report as such 


  • I wouldn't make the assumption that all fixed appliances are tested as part of the electrical installation.


    I would hope at least earth continuity to the element in a shower, but I've definitely come across electricians who only test to wiring termination points, because that's where BS 7671 stops (the Wiring Regs apply to electrical equipment and assemblies only as far as their selection goes ... not their inspection and testing).


    Also, the IET Code of Practice covers appliances and equipment that is directly wired too - that's why it's called IET Code of Practice for In-Service Inspection and Test of Electrical Equipment and not IET Code of Practice for Portable Appliance Testing.


    This is confirmed in the preface to the 5th Edition of the IET CoP, which has the following statement (my underline):
    Another principal clarification is the demarcation between equipment connected to a fixed electrical installation and the installation itself. Generally, fixed-wiring electrical inspections will verify the installation as far as the connection point for equipment. This can leave many items of permanently installed electrical equipment (such as hand-dryers) failing to be checked, as they neither come under a company's ‘portable appliance testing’ (PAT) regime (because they are not portable appliances), nor under the fixed wiring inspection and testing programme.