Electrical Fault Finding

In our last post we touched on a basic technique for finding faults on an Electrical Installation. This week we will continue with another example, but before we do, some great news. The Manual for Electricians Volume 1 is now available. Inside you will find a variety of topics all put together in a book that you can use as a reference when needed. If this may be of interest to you, you can get hold of a copy by following this link: http://lulu.com/spotlight/SparkyHelp

Now to the post

You will at some stage come across an Earth Leakage Device that keeps on tripping and this can be a very tricky fault to find. Let’s look at a structured approach to solve the problem:

Unplug all appliances that are on the circuit and try to reset it. If it resets, put them back one at a time until you find the faulty appliance

If it still does not reset, turn off all power and test to make sure. Disconnect all the neutrals connected to this device. Without restoring power, reset the Earth Leakage to see if it latches. Once it is on, restore power to make sure it does not trip without any load connected.

Now turn off all power again and connect one of the neutrals you removed. Once connected, restore power and if the unit stays on, turn off power and put back a second neutral. Once connected, restore power and check.

Keep doing this until you come across the neutral that causes the unit to trip. That is the circuit on which you have a fault. Turn off all power, remove the neutral and turn power back on. Now you can check to see which circuit has no power to it. Once you have that, turn off all power again and then proceed to work through the faulty circuit until you find the cause of the problem

It may seem to be a long process having to turn off the power every time, but please, always proceed with caution and don’t be tempted to work on a live board.

Hope this helps and till next time, stay safe and strive to be the best at your trade. Next week we will have a look at some instrumentation devices you may come across