When the printer is cold or warming up, the power consumption will increase slightly. This effect is due to the fast wake up time feature that is incorporated into the printer to promote efficient use of energy and to meet the Energy Star rating. This also ensures that the printer will perform at up to 20 pages per minute while printing. The change in power consumption may cause lights to flicker or dim as it draws power from the circuit. You may also experience this condition if you reside in a structure that doesn't meet today's current wiring standards. We recommend not sharing the same power circuit (breaker) with other high-power consumption appliances, for example, air conditions, copiers and shredders. This printer has been tested and approved by Underwriters Laboratories (UL) to meet recognized safety standards.