troubleshooting electrical faults

see also:

• electricity in Australia
• camping off-grid - power, batteries, solar, fridges
• solar power for camping
• solar regulator / controllers for solar panels for camping
• 12V batteries and battery boxes
• multimeters
• basic electronics
• voltage droop
• DIY tips
• Youtube: better way to join wires

• this is a guide to help you ascertain what is causing your RCD or circuit breaker to trip
• for automotive electrical issues see:
  • car battery running flat or car not starting
  • car electrical systems

• troubleshooting:
  • is it just one device?
    • check the power cords are plugged in correctly and the correct power switch is turned on
    • is there a local circuit breaker for that power switch - if so check it
    • consider removing the cord for 20secs and then re-inserting to “reboot” the device
    • does the device have a fuse - this may be blown
    • try a different power point in case it is an issue with that power point or that circuit
    • otherwise it may be a device failure
  • is it just one power board?
    • you may have over-loaded it and triggered the circuit breaker or fuse on the board
    • remove devices, reset the circuit breaker and try again avoiding excessive wattage or current load rated for that board (usually 2400W in Australia)
  • is it just one circuit in the house?
    • most likely cause is either the circuit breaker or RCD have tripped - check the circuit board and then see below for troubleshooting
  • is it the whole house?
    • check you neighbours - it may be a local blackout
    • if your house is the only one - check you circuit board main power switch
      • if the circuit board seems fine, perhaps your power company has stopped supply due to unpaid bills or a power company issue

• this is due to an excessively high current occurring and is usually caused by either:
  • short circuit
    • this is generally caused by faulty wiring or faulty electrical device
  • excessive power load current draw
    • most household power circuits in Australia are rated to 10A 240V = 2400W (some circuits are rated to 15A such as kitchen ovens)
    • if you exceed 2400W on one circuit then the fuse will blow or circuit breaker will trip
  • lightning strike
    • this would be a rare cause and likely to trigger all circuit breakers or fuses
• troubleshooting:
  • check devices on that circuit to ensure they are not combining to give excessive wattage
  • turn all devices off on that circuit, turn circuit breaker back on
    • if it trips immediately then there is a short circuit in the wiring from switch board to the power points
    • if it doesn't trip, sequentially turn on all power points on that circuit
      • if one trips it then that is the fault
      • if it hasn't tripped then try sequentially running each device on the circuit

• this is due to detection of current leaking to ground from either the active or neutral wires
• NB. circuit breakers, fuses and power switches are generally breaking the active line of an AC circuit - thus if the RCD is still tripping despite all these being OFF, then the issue is likely to be a faulty RCD device or less commonly, a persistent neutral line to ground leak (these do not generally create enough current to trip an RCD but could do so)
• this is usually caused by either:
  • if occurs after new RCDs installed:
    • new RCD is more sensitive than older ones and thus may trigger when the old one didnt from low earth leakages of 30mA
      • clamp-meter the earth or neutral to measure leakage milliamps with the appliance running before trip, to see how close to 30 mA it is
    • MEN/earth bars are not configured correctly for your board layout
    • neutral being shared with other RCDs - this is particularly likely if BOTH RCDs have tripped at the same time (both do not need to trip for this fault to be present)
  • a faulty appliance
  • damaged insulation on wires
  • exposed neutral wire contacting ground (could be an active wire but without enough current to trigger the circuit breaker or fuse)
  • moisture near electrical wiring
  • faulty RCD device
• troubleshooting
  • you may know what caused it by it happening as soon as an event happened such as turning a device on or house maintenance where wiring may have been affected
  • turn off all circuit breakers that are controlled by that RCD
    • if RCD still won't reset to ON, then it may be either:
      • a neutral wire leaking current to ground
      • a faulty RCD device
    • if RCD resets to ON, then sequentially turn back on the circuit breakers
      • if the RCD is triggered when turning on a circuit breaker then the fault is in that circuit
        • turn all power switches off on that circuit
        • if the RCD still trips when turning that circuit breaker on, it suggests a neutral wire leaking current to ground
        • if RCD resets stays ON when the circuit breaker is turned on then sequentially turn back on the power switches on that circuit
          • if the RCD trips when turning a power switch on then the device connected to that switch is faulty
          • if RCD resets stays ON then you may need to run a device on that circuit to see if the device is causing the issue