In troubleshooting an NSI architectural system about 20 years old for irratic behavior we found a bad control module. But, in the process we discovered something I do not understand. We had all lamps at full power and then proceeded to trip the breakers one at a time in an attempt to discover what lamps were on what breaker. The lamps in the corresponding circuits did NOT go out. We then turned off the main panel breaker to each dimmer pack. The lights still did NOT go out. How is this possible? The NSI tech, who admitted to not being an electrician, did not have an answer. He also said he had never heard of this situation in the past. Can anyone on this forum offer a suggestion? Any help would be appreciated.