Electrical fault finding?

[macka09]

Hi guys. I’m still very new to boiler fault finding but was wondering whether you could advise me on a particular multimeter or tester that would help with fault finding? The wife has been a good one and got me a Martindale ET5 open jaw tester but I’m unsure whether they’re any good? I can’t really find much on YouTube about them so any advice would be great. Plus, it’s not a cheapo, I thinks it’s inline with the Fluke 113 for price. Cheers

 

[Deleted member 120897]

I bought a cheapish Extech one (approx £35), which was good, although the batteries kept coming out inside, but that might have been because I was a bit careless with it.
I then damaged the probes, but replacements were a little expensive. I then bought an Amprobe (now owned by Fluke) which is an ok bit of kit, abut more DIY, but they do better testers, cheaper than Fluke.

I’ve since bought a Fluke 117 (second hand from eBay), which hasn’t had much use. I use my 2 pole voltage tester more, probably because I don’t want to damage my multimeter 😉, but also because you’re now supposed to use these for dead testing.

Martindale produce decent equipment, so I’ll say it’s probably a decent piece of equipment, and ok as a multimeter.

 

[Murdoch]

It really depends on what type of testing you have in mind?

 

[Basher]

Your Martindale ET5 does everything a reasonable multimeter would do, and to me looks a decent piece of kit.
I've an electrical background, and use a (Megger) Avo 410 amongst others, but your ET5 has jaws, and temperature measurement as well, so seems pretty well suited to me. It seems to have protection from being 'blown up' through selecting an incorrect range!
Just a question of getting familiar with it I guess?

General advice on fault-finding will be equally valid for any high impedance digital meter.

Don't use the ET5 voltage sensing feature for dead testing though! As per Undertrained, use a 2 pole voltage tester for that.
I use a Martindale one of those 🤪

 

[Ric2013]

Don't use the ET5 voltage sensing feature for dead testing though! As per Undertrained, use a 2 pole voltage tester for that.
I use a Martindale one of those 🤪

Seeing as the answer might save my life, what's the advantage of a 2-pole voltage tester over a multimeter set to AC Volts scales and then DC Volts scales other than you risk selecting the wrong scale and burning the circuitry?

 

[Deleted member 120897]

You’ve already answered your own question, a 2 pole voltage indicator, approved to GS38 shouldn’t give a false reading, or being selected to the wrong setting. GS38 is the HSE document that gives guidance on this.

 

[Basher]

As per Undertrained

https://lclawards.co.uk/media/70653/gs38-4th-edition.pdf

 

[Chuck]

Seeing as the answer might save my life, what's the advantage of a 2-pole voltage tester over a multimeter

IMO, the non-contact voltage measurement feature is of limited use. You can't rely on it to prove a dead circuit but it might be useful in some circumstances, e.g. tracing a live cable.

Typical fault finding needs only very basic scales; volts and ohms mostly, amps occasionally. An audible continuity test is also nice to have. The ET5 has a backlight for the display and 'torch' facility, which is a plus for usability but it doesn't have scales for currents in the range 0.1mA – 1A, which is a minus. For work on heating/plumbing systems 'rugged' trumps 'precise'.

 

[Deleted member 120897]

IMO, the non-contact voltage measurement feature is of limited use. You can't rely on it to prove a dead circuit but it might be useful in some circumstances, e.g. tracing a live cable.

Where did non contact voltage indicator’s come into it?

 

[Chuck]

Where did non contact voltage indicator’s come into it?

It's a feature of the ET5.

 

[Basher]

Where did non contact voltage indicator’s come into it?

The ET5 has a 'non-contact' voltage probe feature built into one of the jaw tips. Maybe useful, but not something to use for dead testing!
Edit - sorry Chuck - beat me to it

As an aside, I hadn't noticed that the ET5 dc current ranges started at 0.1A so that is less sensitive than a typical multimeter.
I think it can only measure current using the 'jaws', so you can't use the leads for that.
How often do you need to measure low-ish currents with boiler maintenance - I'm interested to hear if this is an issue?

 

[Deleted member 120897]

How often do you need to measure low-ish currents with boiler maintenance - I'm interested to hear if this is an issue?

I can’t say I’ve ever needed to measure currents for a boiler or heating system, other may have and can verify.

 

[Deleted member 120897]

Sorry, I was confused, Chuck quoted Ric when he asked about 2 pole voltage testers, but then mentioned non contact voltage testers 🧐

 

[ShaunCorbs]

It can be helpful when having a look at pumps low amp modes as most pull around 0.2 amps or less

 

[macka09]

So what’s the overall consensus then chaps? Get to grips with the martindale because it’s good enough or return it and get the 113? Cheers fellas. Always good to hear other peoples opinions.

 

[Chuck]

So what’s the overall consensus then chaps? Get to grips with the martindale because it’s good enough or return it and get the 113? Cheers fellas. Always good to hear other peoples opinions.

AFAIK, the Fluke 113 doesn't measure AC or DC current at all so I'd keep the ET5.

My preferred option, however, would be to trade up to the Fluke 115, which adds DC and AC current ranges and is designed for field technicians, which matches your profile a bit better. A bit more expensive than the 113 but it's a tool and I consider a good tools to be an investment.

 

[macka09]

For safe isolation do I need to have a 2 pole tester as well? Are the multimeters no good for this?

 

[Basher]

For safe isolation do I need to have a 2 pole tester as well? Are the multimeters no good for this?

Strictly speaking, yes, you should have a 2 pole tester as well.
The reason being it is thought too easy to set a meter to the wrong range, or the meter might be faulty, or the user mis-interpret the reading as safe when it's not etc. etc.
The idea is that a 2-pole tester is much more likely to give a reliable indication, and is unambiguous.
And from a HASAWA angle, a professional would be expected to have the appropriate equipment for the job 👍

 

[Deleted member 120897]

For safe isolation do I need to have a 2 pole tester as well? Are the multimeters no good for this?

If you work for a firm, possibly the same might apply to subbying, you’ll be bound by their working practices as well.

 

[macka09]

Strictly speaking, yes, you should have a 2 pole tester as well.
The reason being it is thought too easy to set a meter to the wrong range, or the meter might be faulty, or the user mis-interpret the reading as safe when it's not etc. etc.
The idea is that a 2-pole tester is much more likely to give a reliable indication, and is unambiguous.
And from a HASAWA angle, a professional would be expected to have the appropriate equipment for the job 👍

It’s quite funny you say this. Out of the companies I’ve worked for as PAYE, I’ve never seen another engineer carry out any safe isolation practices. Even when I’ve worked along side the company owner.

 

[Deleted member 120897]

It’s quite funny you say this. Out of the companies I’ve worked for as PAYE, I’ve never seen another engineer carry out any safe isolation practices. Even when I’ve worked along side the company owner.

Tbf though, I don’t if I’m working at the boiler, seems pointless with local isolation at the spur. Majority of stuff is a tick box exercise, but as long as you can prove you can do it, then that’s all that matters.

 

[Chuck]

Tbf though, I don’t if I’m working at the boiler, seems pointless with local isolation at the spur. Majority of stuff is a tick box exercise, but as long as you can prove you can do it, then that’s all that matters.

You should always check. One day you'll come across a system that some clown has got the wiring to a thermostat or pump wrong with the result that there is a second live feed back to the boiler. :-(

 

[Deleted member 120897]

You should always check. One day you'll come across a system that some clown has got the wiring to a thermostat or pump wrong with the result that there is a second live feed back to the boiler. :-(

True, and appreciate the comments, but I’d say 95% of our housing stock is combi boilers. Sometimes I do check, or there are times I do have to check.

 

[macka09]

Tbf though, I don’t if I’m working at the boiler, seems pointless with local isolation at the spur. Majority of stuff is a tick box exercise, but as long as you can prove you can do it, then that’s all that matters.

My wife literally just said “why are you looking at electrical meters so much, surely you’d just take the fuse out to be on the safe side”. Knows her stuff haha

 

[Chuck]

My wife literally just said “why are you looking at electrical meters so much, surely you’d just take the fuse out to be on the safe side”. Knows her stuff haha

Assuming that the house was correctly wired with the fuses in the live feeds.

And the second thing that apprentices are taught (right after how to make the tea) is that you never 'assume' things. (The first is how to make tea properly.)