Domestic Appliance Testing

[squadman]

Re: Domestic Appliance Testing

Not only are we ensuring the appliance is safe for the customer but also that it is safe while we work on the appliance. Any court looking at the duty of care aspect should there ever be such a circumstance will look at the working procedures of the engineer or company involved, if they cannot make any sense of what recognised practices should be used they will seek the advise of a expert, if it were then determined that the working practices showed no duty of care I fear the worse for those involved in such a situation. Martin is correct that all of us should be using at the very least a Insulation Tester, Polarity Checker and good visual inspection of the appliance under repair and its associated connection. Thats the very minimal we should be working to and anything less in my view is bad working practice !

A So called engineer once said to me in general conversation when asked if he used a Megger, What ! I never needed one ! and in any case any earth type faults with them things only mean more time on the job looking for daft faults !

I dare say he is not alone in this industry and some go through life without such tools, such knowledge and a whole bunch of luck in their toolbag !

[fasetester]

Re: Domestic Appliance Testing

leavemetogetonwithit wrote:

funkyboogy wrote:
does anyone know of a voltstick type thing that would also give a audible noise ,,, where you could clamp onto appliance cable …

ally
Hmm. Sounds like an interesting idea screaming out to be invented. So I did a quick Google and found this
http://cpc.farnell.com/jsp/level5/modul … 345078.xml
Looks like you’d have to devise your own clamp though.
Mike.

mike does this volt stick check for broken netural say i was checking a broken flex would it still light if a netural was broken or does it only detect broken live thanks fasetester

[Martin]

Re: Domestic Appliance Testing

fasetester wrote: or does it only detect broken live

Just detects the live fase (pardon the deliberate pun 😈 )

[fasetester]

Re: Domestic Appliance Testing

Martin wrote:

fasetester wrote:
or does it only detect broken live

Just detects the live fase (pardon the deliberate pun 😈 )

is their any martin that detects netural thanks fasetester

[Martin]

Re: Domestic Appliance Testing

No! Though if you want to be clever in order to detect a neutral break in the flex when your volt stick shows live all the way through. Simply rewire the plug (switch live for neutral) then check again!! Once you locate the break point do remember to rewire the plug top correctly. 😉

[twicknix]

Re: Domestic Appliance Testing

Just want to get it off my chest….I attended the PAT testing course to get some qualification and passed. During the course it talked about how a lot of equipments are sensitive to high voltage testing particularly in IT.

I do know that all appliances have been flash tested at 1000v at the factory, Unless I am wrong…

Can anyone confirm that it is perfectly safe to do 500v insulation test on appliances without blowing out computer boards as well nearly all appliances. I attended a machine recently that had it computer board blew out due to power surge. Hence me asking this question.

Would I be better off carrying out 250v insulation test on the appliance if in doubt?

[Martin]

Re: Domestic Appliance Testing

twicknix wrote:Can anyone confirm that it is perfectly safe to do 500v insulation test on appliances without blowing out computer boards as well nearly all appliances.

I’m sure that they must have explained the correct procedure to PAT testing a washing machine during your course. But, in case others are scratching their heads in wonder at reading this, the subject is covered in a download available HERE 😀

Using that method of testing the earth return path (a.k.a earth bond) should NOT cause damage to machines controlled by electronic circuit boards. The basic premise toward that statement is that the control boards (modules) are designed to operate as an AC circuit. Whereas the 500volt Insulation Tester generates a test voltage in DC. And, generally speaking that is, AC circuit boards will not be damaged but any potential DC voltage being applied through them.

[twicknix]

Re: Domestic Appliance Testing

Martin wrote:

twicknix wrote:

I’m sure that they must have explained the correct procedure to PAT testing a washing machine during your course. But, in case others are scratching their heads in wonder at reading this, the subject is covered in a download available HERE 😀

Thanks Martin,

The course I attended is PAT testing course, they did explain the procedure with earth bonding, insulation test and all that. But they keep referring to IT – I guess most of the candidates were in the IT business, so I kinda got muddled up. I rather be safe than sorry that is why I am asking you guys what the best way of doing it,

[squadman]

Re: Domestic Appliance Testing

Couple of enlightening documents as regards Appliance Testing and use of the appropriate tools.

I was curious about Page 4 regarding the use of the Clamp Meter to observe Earth Leakages, which states :

You can even observe the earth leakage potential by clamping the earth lead as in the final illustration below: – This is true but what about the following scenario ?

To check the earth leakage in a single-phase circuit, one method is to clamp the meter round the live and neutral conductors simultaneously. The currents in the conductors should, of course, cancel out so that the instrument reads zero, but if there is any leakage to earth this leads to a difference in the phase and neutral currents, which can be read from the instrument display. Alternatively, the instrument can be clamped around the earth conductor so that the current flowing in this is measured directly. It should be noted, however, that this will not necessarily show the total leakage, as current may be finding its way to earth via routes other than the earth conductor.

I did of course take onboard that you did specifically make reference to reading Earth Potential Martin.

I have always used a Megger, Multitester, Clamp Meter, Polarity Tester, Digital Thermostat and all of these tools make my job a hell of a lot easier, in the case of the Clamp Meter its invaluable for integrated appliances !

[Author]

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