My new Megger MFT 1730

[eveares]

Just to let you know I have just bought a Megger MFT 1730 for £575 that includes a years calibration from ebay.

Here is the eBay listing: http://www.ebay.co.uk/itm/Megger-Mu...ip=true&rt=nc&_trksid=p2047675.l2557#viTabs_0

Regards: Elliott.

 

[JohnW2]

Just to let you know I have just bought a Megger MFT 1730 for £575 that includes a years calibration from ebay.

Well done - although I have to say that that is more than I would personally pay, or would feel that I needed to pay, for a secondhand MFT - particularly since, as I pointed out before, you could buy a new MFT for that sort of price. I hope you enjoy your purchase and have fun with it!

Kind Regards, John

 

[eveares]

I have to say that that is more than I would personally pay

But how much would it have cost new? (without the Powersuite software)

 

[JohnW2]

But how much would it have cost new? (without the Powersuite software)

I think that one would have cost around £1,000 new. However, as I said, before, you could have bought other MFTs for the sort of price you paid - e.g. (I think I gave this example before) a Fluke 1662 for around £550 (plus VAT).

Kind Regards, John

 

[eveares]

However, as I said, before, you could have bought other MFTs for the sort of price you paid

I appreciate that, however at least I have got the specific model of MFT that I wanted. Maybe I could have saved a couple of hundred if I waited, but oh well I am happy now.

 

[JohnW2]

I appreciate that, however at least I have got the specific model of MFT that I wanted. Maybe I could have saved a couple of hundred if I waited, but oh well I am happy now.

That's what matters. I hope you enjoy it, and that it gives you a good few years of service.

Kind Regards, John

 

[Iggifer]

I realised the other day I bought my 1552 this time 6 years ago. Still going strong in almost daily usage to some extent.

Calibrates no problems and all it’s needed in that time are some new leads, and a cheeky little internal solder repair.

I paid about £250 for it in 2011

The 1731 is under £1000 new, and to be honest the only bonus over my MFT realistically is 2-wire no trip and phase rotation. Is it worth it for me to upgrade at this point? Nope

 

[JohnW2]

I realised the other day I bought my 1552 this time 6 years ago. Still going strong in almost daily usage to some extent. Calibrates no problems and all it’s needed in that time are some new leads, and a cheeky little internal solder repair. I paid about £250 for it in 2011

... and I hope it continues to serve you for a good few more years.

As you will probably recall from my thread about it a little while ago, I bought my Fluke 1652 about 8 years ago for not much over £100 (can'r remember exactly - maybe £130) and it worked fine until very recently, when it developed what seemed to be a silly/frustrating fault. At not more than around £16 per year, I reckon I did pretty well. The recent replacement (same make/model) cost about £200, and it remains to be seen how it lasts!

The 1731 is under £1000 new, and to be honest the only bonus over my MFT realistically is 2-wire no trip and phase rotation. Is it worth it for me to upgrade at this point? Nope

I can understand that.

As a matter of interest, do you know hoe "2-wire no trip" works? As with many MFTs (possible all of the vintage of mine), I can do 3-wire no-trip (which I understand), but 2-wire L-E loop impedance very much causes a 'trip'!

Kind Regards, John

 

[Iggifer]

As a matter of interest, do you know hoe "2-wire no trip" works? As with many MFTs (possible all of the vintage of mine), I can do 3-wire no-trip (which I understand), but 2-wire L-E loop impedance very much causes a 'trip'!

I've only ever used the 2-wire no trip function a couple of times, but I can only assume it uses ~20mA for the test. This obviously means it takes longer and is, to a certain degree, less accurate than a hi-current test.

My 1552 takes ages to do a 3-wire no trip, and when I've checked it vs the 2-wire the reading has been sometimes up to 0.10Ω out - not a big deal in the grand scheme of things, but could be the difference between an OK reading and a fail on a particularly long circuit

 

[JohnW2]

I've only ever used the 2-wire no trip function a couple of times, but I can only assume it uses ~20mA for the test.

I suppose that would be the obvious answer - I suppose one could put constant current circuitry between L and E and measure the consequential change in L-E pd, but that would be pretty tiny (about 7mV with 20mA and and EFLI of 0.35Ω).

This obviously means it takes longer and is, to a certain degree, less accurate than a hi-current test.

In view of my above comment, I can well believe that it would be less accurate, but it's not 'obvious' to me why it takes longer (does it perhaps make multiple measurements in an attempt to improve accuracy?).

My 1552 takes ages to do a 3-wire no trip, and when I've checked it vs the 2-wire the reading has been sometimes up to 0.10Ω out - not a big deal in the grand scheme of things, but could be the difference between an OK reading and a fail on a particularly long circuit

My Fluke 1652 takes a second or two. As for the different readings you mention, strictly speaking, if you only have two (different) results, you can't be certain as to which one is closer to the truth (although, as I presume you're doing, one can make an educated guess!).

Kind Regards, John

 

[Iggifer]

In view of my above comment, I can well believe that it would be less accurate, but it's not 'obvious' to me why it takes longer (does it perhaps make multiple measurements in an attempt to improve accuracy?).
My Fluke 1652 takes a second or two. As for the different readings you mention, strictly speaking, if you only have two (different) results, you can't be certain as to which one is closer to the truth (although, as I presume you're doing, one can make an educated guess!)

Maybe it's just a foible of the 1552. It takes a fair while to do RCD testing too. You can hear relays clicking away as it charges and discharges capacitors and whatever other fancy stuff it's doing under there

 

[JohnW2]

Maybe it's just a foible of the 1552. It takes a fair while to do RCD testing too. You can hear relays clicking away as it charges and discharges capacitors and whatever other fancy stuff it's doing under there

Ramp testing obviously does take a little time, because it has to undertake multiple tests and, as you say, get its act together in between each one.

Kind Regards, John

 

[Iggifer]

Ramp testing obviously does take a little time, because it has to undertake multiple tests and, as you say, get its act together in between each one.

Kind Regards, John

Ramp testing or auto RCD testing?

On auto it should have enough time between the RCD tripping and the power being reset to have fully charged - seems it still takes it’s time though

 

[eveares]

It arrived today! Even came with rechargeable batteries!

I will post more in due course, although have played around with it a little and all seems good. Even the free Megger download manager is not bad for simply getting the stored results on to your computer via Bluetooth.

Tested my External loop impedance (TN-S Arrangement) with 2-Wire high current and got a nice reading of 0.16Ω for Ze.

 

[ban-all-sheds]

There's a new, never-been-out-of-the-box one on eBay now for £500.