megger 1552 sine wave symbol

telectrix said:

i'll buy it if the price is right, i love megger gear.

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Off on holiday in the morn for a week , if i remember i will have a look for it when i go back down to Bucks and i am at the stores again .
It will probably around the 5th Sept , so feel free to pm me and remind me around then .

dp, i'm 65. how in hell do you expect me to remember as far away as after tomorrow?

For that little gem tel , i will actually now go and write it in me dairy . Thanks for that one , made me chuckle !

actually, after tomorrow was being optimistic. i'm lucky to remember after the next pint.

SPARTYKUS said:

Had my 1552 for over 4 years. It has displayed that symbol maybe 3 times.

It did not go ---- up immediately after.


It would be nice if a megger chap gave a thorough detailed explanation of what this symbol means?

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The noise warning symbol is a sine-wave with a spike on the positive half cycle, seen at the top of the display just right of centre on an Megger MFT 15xx.

The noise warning symbol on a Megger MFT 15xx, 17xx or 18xx is very rare event, due to the multi-pulse, noise cancellation measurement method employed. It is because of this patented technique that the Megger MFTs gets unfair criticism from users of other MFTs (Fluke devotees in particular) for it's apparently slow "No-trip" test, however, Megger users get the last laugh because they very rarely have their test inhibited by a noise error whereas Fluke users see their equivalent, Error 5, fairly regularly even in the domestic environment. Most Megger users reckon on it occurring about once a year, maybe a few more if you do lot of industrial work, and usually on a No-Trip loop test.

The noise warning symbol is displayed when there is excessive noise on the supply. Noise or transients on the supply voltage can effect the accuracy of the loop measurement during the test and introduce an error in the reading. The noise or transient on the supply voltage are usually caused by active appliances or equipment on the supply, the source usually this internal to the installation, but equally may be caused by an external source. Internal sources can usually be isolated (switched OFF) eg. automatically switched loads and motor controllers, however, when external sources are the cause it may require testing at a different time of day to avoid the active period, during their lunch hour or after normal working hours eg. A garage down the road maybe using welding equipment or the Vets /Doctors surgery using X-ray equipment.

If the noise warning symbol is displayed the reading should be treated as in-accurate and the test repeated, usually a second test is all that is required to get a reliable reading. If the noise symbol continually appears on repeated test the cause should be investigated.
[FONT=&amp]In an industrial environment where continuous production must be maintained and the noise source cannot be isolated, often the only thing you can do in the short-term is to take a series of readings and record the average value to minimise the error.

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dpelectricalltd said:

If i remember correctly , this is what my megger used to show when it went up s""t creek ?
Each time was followed by a rather expensive repair and get this ! The need to pay for a recalibration as megger would not do it at the same time as the repair ???
It happened 3 times in one year about 5 years ago and thats when i went for a top line fluke and touch wood to date !!!

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This type of behaviour is typical of a faulty Megger MFT continually displaying the hot warning symbol, when Hi-current loop testing, despite ensuring the MFT has cooled down between tests. Usually caused by a loop load that has reduced in value outside the manufactured tolerance and is being 'cooked'.
The hot warning symbol is a 'thermometer' seen at the top of the display on the far right hand side, on a Megger MFT15xx.
Because the repair of this type of fault requires the replacement of a number of components parts the instrument inevitably requires adjustment and re-calibration to ensure its intended accuracy is brought within the manufacturer's original specification.

SPARTYKUS said:

Had my 1552 for over 4 years. It has displayed that symbol maybe 3 times.

It did not go ---- up immediately after.


It would be nice if a megger chap gave a thorough detailed explanation of what this symbol means?

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Thanks Markie
Exactly what I wanted to know

maudy said:

Thanks Markie
Exactly what I wanted to know

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Pleased to have helped.

Hi Telectrix , i know it has taken about 8 months but here it is !
It has been in a flight case on a shelf in the stores for the last 6 years or so after it played up last time .