Topic | Measuring 460 VAC forces disconnect then firmware update

Home Forums Mooshimeter Support Measuring 460 VAC forces disconnect then firmware update

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    • #9589 Reply
      Anonymous
      Inactive

      Hello, I am using IOS 9.3.1 on Iphone5. I have FW Build: 144740000 on the meter. I can measure 240 VAC with no problem. When I try to measure 460 VAC, it may or may not show the measurement. Usually, it forces me to reconnect the meter. I was able to read it once or twice without issue, until I removed the probe from the voltage source (460 VAC Supply Outlet). When I removed the probe, the meter disconnected.

      When I reconnect the meter, it shows that it is downloading the firmware to the meter, which takes a minute or two. Then the meter is fine until I try to measure 460 VAC again.

      So this sounds similar to the bug fix you just released, but the difference in what I am seeing is that in addition to the disconnect, the meter goes into a firmware download upon reconnection.

      Lower voltages have not presented any problem. Nice product, but I do work in panels that run 480 VAC pretty regularly, so I hope you can help me out.

      Thanks,
      Jim

    • #9592 Reply
      Anonymous
      Inactive

      Correction: FW Build: 1447470000

    • #9593 Reply
      admin
      Keymaster

      Hi James,

      This is helpful data, thanks. I just bought the equipment necessary to do 480V testing so I hope to have better answers for you soon.

      It sounds like this is not the same bug as the 240V AC disconnection, because in that case the meter did not reboot.

      I have a suspicion. If it’s convenient, can you try manually setting the meter to the 600VAC range before connecting it to the 480V circuit? My hunch is that there’s some sort of deviance in the overload protection circuit, and since the meter defaults to 60V measurement mode, 480V is overloading it in such a way that it forces a reboot before the autorange can kick in. If my hunch is correct, I’ll write a patch.

      Thanks again, best
      ~James

    • #9606 Reply
      Anonymous
      Inactive

      James,

      I ran your test by Manually setting to 600 VAC and it measured just fine. Then I tested again but first set the range to 60V in Auto. It also worked just fine. For some reason, I cannot reproduce the problem today.

      The only difference is the source voltage I am measuring today. Today I am looking at 480 VAC (at my customer’s location). Previously, I was looking at 460 VAC at my office.

      I will try again at the office when I can, probably tomorrow. I verified the actual voltage is 460 at the office with another meter. I will also try again today as time permits.

      Thanks,
      Jim

    • #9607 Reply
      Anonymous
      Inactive

      James,

      I just thought of the only other thing that was done between the two tests. The test I did that failed at 460 VAC was done last Friday. This weekend, at home, I removed the batteries from the meter to check their voltage. They were good.

      Before replacing the batteries in the meter, I bent the connection tabs in to ensure a tight connection with the battery.

      All testing I have done today so far is good. Not sure if that may be related, but I wanted to be sure you know all that I’ve done.

      Thanks,
      Jim

    • #9612 Reply
      admin
      Keymaster

      Thank you Jim!

      That’s really interesting… the same meter gives different behavior measuring 480VAC.

      It’s a tough diagnosis. I’m trying to think what impact a marginal battery connection could have… the best hypothesis I can come up with is tenuous. It goes like this: The inputs to the ADC have a clamping path that dumps back to the batteries (there’s enough series resistance that the current involved is on the level of hundreds of microamps). It may be possible that there was a tenuous connection to the battery, and the overvoltage clamp did not function correctly, which was causing the overload and reset events that you witnessed the first time.

      It’s hazy and tenuous but that’s all I can think of right now. I’ll let you know if I see the answer in a dream. I’m glad it’s working for you though, please let me know if you discover anything new.

      Best
      ~James

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