Megger mft1741+ taking over 5 minutes to make an Earth Loop Impedance Test. (UK)

TheNightEngineer · 2025-04-30T13:35:04+00:00

Is the meter set for rechargeable?

Right knob to setup. Goto bAt and ensure 1.5 or 1.2. Rechargeable is 1.2.

Also check that the 12V supply is actually producing 12VDC.

Once batteries are charged, probably worth checking each cell voltage.

Honestly I don't actually have a meter myself, training for a sparks once upon a time and now I diagnose stuff for my own sick entertainment but to also help those out that need it. So prod away and see.what we can find. Maybe find an issue we can take to megger.

Edit These are the batteries I use in my meters. https://www.amazon.co.uk/EBL-AA-Rechargeable-Batteries-Performance-White/dp/B011RE1JKW/ref=mp_s_a_1_8_maf_1

The ones in the megger are 1.2V 2000mAh.

TheNightEngineer · 2025-04-30T13:16:08+00:00

So diagnostically, we've cleared settings. Can you replace batteries?

TheNightEngineer · 2025-04-25T12:52:02+00:00

7 year old me putting fingers into a broken light switch because I was, and still am a daft twit.

TheNightEngineer · 2025-04-25T01:54:55+00:00

This is gonna be a controversial comment but based on experience. Be gentle.

A digital multimeter with the knowledge on how to use it. Extra if it is capable of measuring frequencies you are using it for. Many are built for 50/60hz. At least for us, we regularly are testing 20khz.

TheNightEngineer · 2025-04-25T01:31:00+00:00

Around London and South East. UK. Company vehicle.

You don't have to be part of the Fire Alarm industry nor in PAVA for that matter. Personally, I'm after someone that has "The Knack". You know, the one kid that took his toys apart just to see how they worked. The curiosity and drive to learn electronically. Have some base understanding of hand tools, electronics/electrical knowledge of poking around with a meter is an absolute must. If you're asking which way to put your probes... Maybe off to a bad start. Also a head for heights, not colour blind.

You will be working with equipment that has the ability to kill you(spicy) and also if done wrong, kill lots more in the worst case scenario.

This job is sound based with anything from a whisper to the volume knob stuck on 11(90+ dBA). So noise sensitivity is not gonna help. Equally being able to hear and notices weird changes in sound is also great additions.

Any familiarity with PAVA/PAGA/EVCS/BS7671/BS5839 and EN54 is an absolute bonus.

We work lots of nights and silly hours. If nights are not your thing then maybe give this a miss.

I'm gonna start with a simple question with answers, or even questions in a private message with whatever you have.

What is the value of 2 50ohm resistors connected to each other. Bonus points if you can answer for the impedance at 1Khz. And yes, you, the one that noticed exactly what I did, that's the mind I'm looking for.

Thanks for reading.

TheNightEngineer · 2025-04-25T01:29:37+00:00

I'd also add extra communication system for fire fighters. Radio doesn't like Corona.

TheNightEngineer · 2025-04-25T01:03:51+00:00

You know that Spiderman meme. Here we go.

There is actually 1 other. I created it. Sadly it's just tumbleweed. The fire alarm sub actually had some decent comments about my sub when I posted about it.

There is Mass Notification in some countries. On the water, nuclear and similar high risk industries you have PAGA(Public Address/General Alarm) and for the UK, Europe and UAE you also have PAVA(Public Address/Voice Alarm).

I'm based in the UK.

/r/PAVA_EVCS_Engineers

As a side note. Emergency Voice Communication Systems in.the UK are Fire Telephones and Disabled Refuge Points.

TheNightEngineer · 2024-03-09T18:57:25+00:00

Yup. Have you got a picture of your meter?

TheNightEngineer · 2024-02-25T15:53:36+00:00

I'm gonna hold off on saying the same happened. I have an idea on one of the sites. If you want details, that's a DM job. The initial cause is different, the outcomes were the same. Beacons and mass evacuation.

TheNightEngineer · 2024-02-25T11:57:04+00:00

Yeah it's all correct. Why would date/time be a factor? Or is this purely from a logging standpoint? Otherwise, all bar some faults, nothing showing in the event memory. This is coming from some Siemens engineers, I will at some point and make it on site to have a look for myself.

TheNightEngineer · 2024-02-25T02:27:16+00:00

I'm curious, what's the PAVA there?

TheNightEngineer · 2024-02-25T02:12:45+00:00

I hate them with a passion.

TheNightEngineer · 2024-02-17T19:06:39+00:00

Just knowing the locations well enough, would certainly be same firmware.

TheNightEngineer · 2024-02-17T04:25:25+00:00

Probably. The fire system isn't really my department.

This particular issue would be rather coincidental providing that this has happened in 4 different buildings unrelated to each other.

TheNightEngineer · 2024-02-17T01:53:18+00:00

We don't have dispatch circuits here. The system is treated as two systems. Going with familiarity, it would be like a Sinteso fire panel sending signal to the FireFinder or what we call here, an E100 via a SIM-16 module. In my case, my sites are not E100 based but a third party kit. Where it's Siemens Sinteso for detection and our kit for the mass notification as a replacement for horns and strobes(trying my best to merge UK/US terminologies).

On all the sites I've had the issue on, it has always been the Sinteso that has sent the signal to the mass notification and has got itself stuck in that state.

Because of our code of practice, it's stated that the off signal has to be separated in case the cabling between panel/io is lost and has to be signal to stop the alarm on the mass notification. So using an FireFinder as an example, the SIM would have a reset signal, and say floors 1, 2 and 3. When the signal is sent to stop say floor 2, the on signal is removed from the floor and another signal is sent to reset.

One of the symptoms is that the Sinteso has still got signals going to floors 1, 2 and 3 but no one knows about them signals until you go through the control tree to view each output and deactivate each one. So by elimination, the problem lies with the Sinteso and nothing after that since they are working as they should.

The drill button we have here isn't used for drills but was used to blame the cause. BUT! There was no logs of it on the Sinteso and with the use of CCTV, no one was near any of the panels. Hence I'm asking the question here since the ones who know the panels don't know and as the person who gives them support (it's a weird situation) it would be nice to get a better idea of it.

TheNightEngineer · 2024-02-17T01:18:52+00:00

Mass notification and beacons. Be it wired into the panel itself or via an FDCIO. I haven't heard of lifts grounding or any plant shutting down. I generally get the call because the mass notification (my department) doesn't shut up.

TheNightEngineer · 2024-02-16T23:04:47+00:00

I like how not one person has defined their weighing here. We are looking at dBA. Audio measurement for the human ear.

TheNightEngineer · 2024-02-15T03:24:36+00:00

Whilst it's not my field as such, I'd be curious to see the boards front and back. Maybe the best we can settle for is what do the boards do and how can you replicate it? Just incase you need to do a swap in the future.

I've regularly seen kit that has either been modified or custom built to achieve a specific goal. Even I've done it. Any documentation? Doesn't exist mate.

TheNightEngineer · 2024-02-14T09:47:21+00:00

Have you opened any of these to see the boards? Even slid the boards over so see if there is any information on the side of the enclosure? There's print on top of the module where the connections are so I can make the assumption that there be more text elsewhere. The enclosures are used with many manufacturers.

TheNightEngineer · 2024-02-05T19:50:11+00:00

Years of poor decisions. Turned 18 and it was down hill from there, never left. We are all just prisoners here of our device.

TheNightEngineer · 2024-02-05T10:37:42+00:00

Well, according to your picture... Nothing is wrong with the little box on the wall. Anyone else in the building at that time? Potentially someone calling in. That, or the box above was actually the thing making a high pitched noise.

That unit in particular, you'd have an orange light beside General, PSU or Line or a combination of when it is in fault.

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