Hi. If it's tripping at random on wash, but trips every time on dry then that's strange. If it's tripping at random on wash, and trips at random on drying cycle that is more in line with what would be expected with an intermittent tripping the electrics fault. It seems like it is tripping on both wash and dry cycle so clearly the washing machine is of little use until it is properly repaired. Intermittent tripping can be caused by either leaks running onto electrical parts or chafed wires somewhere that touch something metal during the wash cycle. The latter can be frustratingly intermittent and influenced by the weight of the laundry inside. In other words a heavy load, or a load that is a bit out of balance can cause the tub to bounce about more on spin and subsequently allow the bare wire to touch the casing.
Tripping the electrics every single time would only be caused by a chafed wire if it was constantly touching and shorting to earth, which is very unlikely, or an insulation fault on one of the components. The most common components to cause fusing or tripping of the electrics is either the washing machine heating element, or the dryers heating element, followed by suppressors, capacitors, and motors. An engineer would put his insulation test meter on the washing machine and test for a reading between live or neutral and earth. If there is one you would then have to work out where the leak is coming from. This is achieved by disconnecting suspected parts and seeing if the leak disappears. However, a more accurate method is to disconnect suspected parts and test them individually by putting one probe of the insulation test meter on the metal casing of the part and the other probe on each individual electrical connection point to check for a reading.
As the meter uses 500 V DC but the washing machine and uses 230 volts there is some leeway for small readings. I forget the exact amount that is tolerated. But usually if an insulation leak is tripping the electrics or blowing the fuse is then there is usually a direct short to earth and the needle will shoot straight over.