Need Recommendation on High Quality Electrical Safety Gloves

Leeroy Jenkins on 21/08/2020 - 16:59

Hi guys,

I have an amplifier that I need to fix. It doesn't turn on. I inspected the power supply boards inside (two PCBs that provide power I believe) and I can see no blown caps or other electronics components.

I managed to get the circuit diagram and need to check a few points on the various PCBs to see if all the voltage supplies are correct. I've never poked around on a mains powered circuit, so a good pair of gloves would be a good safety precaution. I'll try to stay away from the primary side of the transformer, hopefully I don't have to probe anything on the primary side.

Long story short, I'll need to potentially troubleshoot a live circuit. I need recommendation of a pair of high quality electrical safety gloves.

Thanks!

Electrical & Electronics

Comments

  • MS Paint on 21/08/2020 - 17:00
    +1

    Long story short

    Pardon the pun

    • Leeroy Jenkins on 21/08/2020 - 17:06

      Thanks. Have you personally used these? Are your hands flexible enough that you can hold some test probes and precisely poke some tiny components on a board?

      • Hybroid on 21/08/2020 - 17:08
        +1

        Probably not well suited to delicate work but should do the job and keep you safe. Prime has easy free returns if it's not suitable for you.

        • BensonP on 21/08/2020 - 17:58
          +2

          Those are way over the top! They are used by linesman on High Voltage. (I use these for work.)

          You're better off with this style, much thinner and rated up to 1000 volts.

          https://www.specialisedforce.com.au/product/balmoral-class-0…

          • AndyC1 on 21/08/2020 - 19:46

            @BensonP: Got to think why the glove is needed for if it's only 240V equipment, not even 3 phase. HV is a different beast. I try to stay away from 240V, but learnt to be careful and how to handle the old TV tube's HV flyback voltages so they could be discharged safely. I hated how they sometimes recharged after a few minutes and bite me when picking the tube up, so I always discharged them again before moving.

            • Leeroy Jenkins on 21/08/2020 - 22:53

              @AndyC1: I'm not sure what line of work you are in, but I think I would be be crazy to not wear some kind of safety gloves when working on a project like this amplifier while it's live.

              To be honest, I don't wear gloves when I deal with simpler stuff like TVs but I think I definitely should. I think it's good I start to think about safety gloves.

          • Leeroy Jenkins on 21/08/2020 - 22:57

            @BensonP: Thanks. They still look a bit unwieldy. I'll do a bit more research on safety gloves and hopefully find exactly what I want.

  • ezekiel181 on 21/08/2020 - 18:14

    Use an isolation transformer while poking around live equipment. https://www.tortech.com.au/product/isolation/isolation-trans…

    • AndyC1 on 21/08/2020 - 19:41
      +3

      I would not recommend an isolation transformer for non techies as they defeat RCD circuits. They have their use in LABS and repair centers and for other special areas, which this is not one of IMHO..

      • Cartman2530 on 21/08/2020 - 20:19

        Correct, they prevent active to ground currents, but not neutral to active on the output side of the isolation transformer. Any mains devices should be approached with caution, especially if the person has little experience with repairing them.

  • AndyC1 on 21/08/2020 - 19:36

    Make sure your lookup chopper power supplies and do NOT go near the 600+V area if its got one.
    Make sure your multi-meter is auto ranging and can take the highest voltage on the schematic.
    Make sure you have decent multi-meter probes and the plastic on the probe/cable is in good working condition.

    And above all if you do not know what you are doing get it fixed by someone who does know what they are doing as no ONE I know of who fixes PCB's needs high voltage gloves as they are for HV sparkies only.

    • Leeroy Jenkins on 21/08/2020 - 22:14

      I never wanted a pair of High Voltage gloves. Well I didn't even know they existed. They look ridiculous and it doesn't look like I can manoeuvre anything in my hands with those on. I do want something a lot thinner as a precaution for this specific repair.

      It's not worth getting someone else to fix it. If I can't fix it, I'm going to throw it out.

      This amp has complicated PCB layout which makes it quite hard to reach and probe some things. That's why I was thinking wearing some kind of gloves in case my hands do slip. I wish it was like a TV power supply board where I could just lay it flat on the bench and probe anything I want, then I wouldn't be posting this question here.

      My meters are fine, I generally grab my Brymen BM235 or a Fluke 27 for repairs. They are great. I'm generally very cautious not to short out anything when repairing things. Don't worry, I always have the probe caps on when i even slightly worry about shorting things.

  • Cartman2530 on 21/08/2020 - 20:16
    +1

    Whats the make/model of the Amp? Maybe I can help you narrow down the problem.

    I personally wouldn't use gloves at all, you are more likely to slip with your meter probes and short something out that way. Better to have really steady hands and multi-meter probes with insulation right up to the tips. if you have regular CAT II probes you can put some heat-shrink over them and that will help you not touch anything you shouldn't.

    • Leeroy Jenkins on 21/08/2020 - 22:06

      It's a Yamaha AV Receiver RX-V630.

      I can't visually see anything abnormal on the power supply board. I also can't easily remove or reach the power supply board because of the ridiculous layout of the PCBs. I'd have to desolder two boards off it.

      When I try turning it on, I can hear a relay click and that's it. It doesn't turn on.

      I was thinking wearing something thin and have some kind of insulation, so if my hands do slip and touch something, I don't get shocked. But the gloves linked above look ridiculous and I don't think i'll be able to hold the probes with those. I generally fix quite a bit of things, but have never worked with anything like this amplifier where it has like 6-7 interconnected PCBs and connectors are all soldered header connections. Some things are quite hard to reach because of how they are laid out.

      • Cartman2530 on 22/08/2020 - 08:23
        +1

        From memory, a capacitor on the main power input board where that relay is goes bad and prevents the power supply from turning on properly. That's what I remember from repairing a RX-557, that's all i have experience with repairing yamaha receivers, yours may be similar.

        Have a look at this video and see if your receiver layout is similar.

        https://www.youtube.com/watch?v=MwvjAtSr5t8&feature=youtu.be

        This service manual for your model with a schematic will be a big help.

        https://www.vintageshifi.com/repertoire-pdf/pdf/telecharge.p…

        Another thing you could do if you aren't confident with probing while the power is on is use hook probes on the points you want to measure, then turn the power on and check. As I said before, the biggest worry isn't you actually getting shocked, its slipping and shorting out a component and causing more damage.

        • Leeroy Jenkins on 22/08/2020 - 13:01

          Thanks, I already had the service manual, and there are several places on the PCBs that I was planning to check.

          The 630 has a different layout from the 557. The power board in 557 is conveniently standing up and facing you, which makes it quite easy to probe, but the 630 has the power board buried under all the boards and half of the board is not visible unless you really peak into case.

          I'm going to use a combination of hooks and normal test leads to do this. Also I don't think I can do it without any kind of hand protection. After doing some research, I'm going to order a pair of class 00 gloves.

          Thanks for the suggestions.

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