Hello guys, I have been called to a site which has 4 toshiba sm800 cassettes, (individual systems) with one controller. The problem is that the controller shuts down at random intervals, and stops all the units, and sometimes its as if system has had a complete power cut. Apparently this has been going on for a few months now, the staff just keep restarting the system.
Because all the systems have there own power supply, and the controller wires are daisy chained, killing the power to any of the units does not affect the controller, and will carry on with whatever units still has power.
I think it is highly unlikely that there is intermittent power failure to all four condensers, I have checked the a/c distribution board, however have not been able to check where that has been fed from., I have also checked for any external timeclocks etc. I am starting to think the controller is faulty, anybody got any other ideas?

Andy