AC LCD volt ammeter went flash - bang

Discussion in 'General Electronics Chat' started by sdowney717, Dec 11, 2014.

  1. sdowney717

    Thread Starter Member

    Jul 18, 2012
    385
    13
    I have 2 broken meters now. The old similar LCD meter was working fine before I redid things.
    I was rewiring the panel, going to add a second meter.
    I plugged the new meter in and left the amp sense current coil disconnected.
    Turned on the AC power and the new meter exploded with a brilliant flash and pop.
    So I then unplugged it and plugged in the old proven working LCD meter. It was reading normal 120 vac and no current. Then a few seconds later it also exploded the same way.

    So what happened??
    Will meter break if current sense coil wire is disconnected?
    Original meter worked fine for 2 years, other was new.

    I closely looked them over and their is no visible signs. these meters are backlit.
    The ones that broke have tiny white ac power plug for volts and a screw wire adapter for current sense coil.

    I plan to buy 2 new ones that use the screw wire adapter for both volts and amps like this here
    http://www.ebay.com/itm/White-100A-...-Panel-Amp-Voltmeter-110V-220V-/390994888707?
    These also have a cover on the back, mine did not.

    Before I get another set, what went wrong with these? And they are dead, backlight off, cant read any numbers.
    [​IMG]

    Thanks to you if you can help.
     
  2. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    you probably had the meter on current across the ac line. remember, voltage across the line, current in series with the line.
     
  3. sdowney717

    Thread Starter Member

    Jul 18, 2012
    385
    13
    Ok, your correct, I messed up the wiring connections.
     
    Last edited: Dec 11, 2014
  4. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    I dont know anyone who has never done that. at least you have a chance to learn from it.
     
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