I have been struggling the last couple of days with irregular earth leakage trips which shut down my show (and th bosses TV). I have been desperately trying to isolate the problem and while I have some theories nothing is crystalising as a single it must be that cause. I have periods when my show runs for an hour or more without problems looping through my entire schedule several times then shuts down pretty much randomly and typically does so again several times as I attempt to reset the earth leakage breaker. It then will run for another 30 mins or more no problems. I am suspecting it is one or maybe several of my power supplies over heating (it does seem to get worse towards the end of the night). To address this i have applied some dimming factors to some display elements to try to lower the draw and slow down the over heating. When I touch the power supplies there are a couple that are warm but none are really hot. Would really appreciate some troubleshooting suggestions. Some details ... the supplies are the typical ray-wu ones in a mix of 5, 12 and 24V. Each have a large clear exhaust port over the fan and are all located well out of the weather. There are varying numbers of lights attached to each. I was using some of the 24V to switch high current relays. I figured this might be a problem as I did not put a resistor in series with the coil to limit the current but removing these from the show does not seem to have stopped the problem. Apart from the power supplies I have disconnected all my 240V elements so there is not likely a fault in any of them causing the problem.