BigB, The first rule of trouble-shooting. Solve the problems that you know about. You know that the circuit is overloaded. You know that a coppier requires a 20 amp. dedicated circuit. You install said 20 Amp. circuit and that is where your responsibilities as an electrician end. If they still have problems it's time to call a repairman. I worked on those machines when I was young and I can tell you without the proper manuals and training that if you attempt to correct problems with the equipment that you will do more harm than good. Those machines require peroidic maintenance anyway.
