¿Why is it advisable to be careful when plugging a laser printer into a UPS?

Laser printers have a high-consumption heating system with rollers that repeat their movement every 30 seconds. This produces a noise because of the repetetion of movement that is constantly being connected and disconnected to the energy provided by the UPS. This noises may damage the computer data. Also, when the rollers heat up, the consumption increases. It is very important that the total consumption of the devices plugged in the UPS does not exceed the value of the UPS.