multimeter suggestions

[mogga]

He's got a avo 1 and an avo 8 and some other one... We've discussed the options now and he's looking at several options now :)

[js.b1]

The Socket & See crowd (or is it Kewtech) have a range of multimeters on Ebay which are in the =A320-30-40 price bracket as I recall and report they compare favourably against the Fluke 197 (or similar).

For domestic electrical testing #1 is RCD tester, #2 is Insulation AND

200mA resistance tester. Most general multimeters do not do 200mA on the resistance test setting and thus not ok with BS7671. Both can be had quite cheaply used or even not that much new if you time things right.

[js.b1]

shows that it could have been from several hundred to as much as 1,000A at 277V."

If so the typical PSSC (L-N) for the UK is typically 1200-2200A, but can be considerably higher.

I never did like cheap multimeter little glass fuses, best kept for automotive use only. If the meter does not disconnect a fault, pulling the probe away allow an arc to form and follow which at a certain distance can flash to meatier prey; in this instance the nearby busbar.

Fused test leads are a Very Good Idea albeit yes expensive.

[Andy Dingley]

Really? I bought a KT62 from eBay specifically to get something that met this 17th ed issue and it still cost me an arm and a leg.

[John Rumm]

make reference to the fuse and its inadequate breaking capacity, however most meters don't even have the fuse in circuit on a volts range, and instead just use it to protect the meter on current ranges.

[js.b1]

I suspect there was a flood of single testers being replaced by "everything-in-one" resters because of calibration costs, age, and perhaps selling 4 boxes at =A365 each knocks =A3260 off a shiny new Megger MFT1553.

For those looking...

1 - Insulation Tester - Good ones are Robin 3050DL 3075DL, Socket & See DIT400. Not much on Ebay right now, Robin 3050DL, NEW, 270666500457, =A389.99+7.99. 2 - RCD Tester - Good RCD testers are Socket & See RCD, Megger, Megger rebranded as Alto Newlec. Not much on Ebay right now, Robin 5404DL for =A345 used no calibration.

Loop Tester is not necessary because regulations permit 1) determination of Ze by enquiry to DNO (external) and addition to 2) direct measurement of R1+R2 via the Insulation Testers 20ohm range with 200mA test current.

[js.b1]

That =A330 Socket & See Multimeter on Ebay is only Class-II at 600V. For comparison a Fluke 179 is Class-IV at 600V and Class-III at 1000V, which might be important to you if a completely blind bat waving probes around live 3ph busbars - or not. The fuse will be pretty substantial on the Fluke re breaking capacity. So there is a reason people spring for the Fluke (which is a very nice unit, sigh, sold mine to buy an RCD tester!).

I have a suspicion the meter used in the explosion was on the wrong range or malfunctioned, there were voltage transients in the area which jumped PCB tracks and set off an arc with no fault disconnect capability re unfused test-leads (Tx fire, phase fault, lightning, everything short of prince of darkness lucas & mandelson walking in the door).

Freak accident, but I too have long wondered why people do not wear flash gear when working. Rubber apron, Class-O gloves, rubber mat, rubber nappies, will do nothing against the flash of particularly PILC letting go. Only high current test I saw was PILC and it is a nasty roman candle affair - longer than the usual flash bang.

[Dave Plowman (News)]

I'd say most have inadvertently gone to measure volts with the thing set to current. I have.;-( And of course that is near enough a dead short.

I don't use a DVM for 'live' mains stuff. Have a probe type one for that.

Once bitten, etc.

[John Rumm]

My ICE Multitest 80 was not very appreciative when I measured the mains input voltage on a PSU with it still set to an ohms range... ;-)

[John Rumm]

Not much help on TT systems though...

The old Megger LT5 is quite handy in some cases since it does a proper high current test - handy for proving MICC and conduit used as a CPC etc. Alas does not have a non tripping range, so a pain on RCD installs.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Adam Aglionby saying something like:

Amazing, the consequences of a cheap piece of tat. When that crappy little meter blew, his fate was sealed.

[Mike Lane]

John Rumm wrote on Nov 25, 2010:

My 20 year-old Fluke would not be perturbed. It has 600V rms overload protection on all ranges. It's one of the best things I've ever bought I think.

[js.b1]

I killed my first (non Fluke!) meter testing the trickle drain on a car battery. First I tried the 2A fuse protected range, but that blew. Second I tried the 10A no fuse protected range, which blew the meter. On re- connecting the battery with meter inline the alarm auto-armed ... operated door locks, flashed indicator lights, closed all windows & sunroof (it was summer)... plus the interior lights came on due to the bonnet being open... plus the various computers.

Trick is leave the battery +ve connected, connect one side of the meter to the negative battery clamp ready. Touch the negative battery clamp to the -ve battery terminal to let the peak draw run, connect the other side of the meter to the -ve battery terminal, then remove the negative battery clamp. Only now is the meter in circuit, after peak draw. As fiddly to do as describe actually, balancing a keyfob & probes.

Likewise, I use the RCD tester to check mains voltage & polarity, current draw via an energy meter.

[Andy Dingley]

A great advantage of the Flukes, where current is on its own terminal and you have to deliberately swap the lead.

[John Rumm]

Same on most of my non fluke ones as well...

[Dave Plowman (News)]

Much easier to fit one of these:-

measuring current a bit more fool proof.

[Dave Plowman (News)]

I've got a car one which prevents you selecting volts while the leads are in the 'current' position (and vice versa) by means of mechanically operated shutters. One step ahead of Fluke telling you 'lead'.

[Adam Aglionby]

Cheap meter leads are the thin bit of copper and the bus bars are couple of phases where you didn`t expect them....

meter leads you say, gone shopping.

Cheers Adam

[The Other Mike]

article but in the UK fused meter probes were being heavily promoted by the HSE, and enforced by proactive companies, at least 15 years ago.

[Andy Dingley]

Ah yes, that's =A3150 quid a year, just for swapping four boxes down into one.