Wondering if anyone can shed any light on an electrical problem I am having. It started about 8 weeks ago with brief power interruptions causing some of my appliances & electronic devices to trip. This stopped but the 2 RCDs in my fusebox then started tripping simultaneously. I had an electrician in who checked the fusebox - all was fine. I then had my fuse box changed from RCDs to rcbos. The trips have continued - all 7 rcbos tripping simultaneously. The power company have been involved - set up a monitor to record the incoming supply. Nothing out of spec the first time - they then set up a more powerful monitor and are currently going over the data - awaiting results. I have unplugged/switched off everything in the house at the same time but all RCBOS still trip. I have gone through each RCBO leaving one off the other six on - no matter which one is off the other six trip out. I have switched off/unplugged everything and plugged in and switched things on one by one with no trips. I have had all my wiring tested and certified - all ok. There is a pattern of sorts - weekdays the trips happen between 7 & 11 am and 3 & 7 pm predominatly. More evenly at weekends. I have run out of ideas & currently both my energy company and electrician are stumped. I would be grateful for any ideas. Thanks in advance.