Take the tour ×  I have an FSP EP1000 UPS.  The User's Manual
says:  CAUTION: NEVER connect a laser printer or scanner to the
UPS unit. This may cause the damage of the unit.  Why is this
restriction?  share|improve this question Lots of good answers
about laser printers. What about scanners? Older scanners used
fluorescent bulbs that might have the similar voltage/current
requirements as laser printers. But recent scanners use LEDs. – 
David Poole Aug 29 '12 at 17:29 add comment  4 Answers  up vote
63 down vote accepted   Why you shouldn't connect a printer to a
UPS  (Unless you accurately size the UPS for peak power
requirements)  When turned on, Laser printers draw a high
current to heat up their fuser roller. A typical UPS cannot cope
with such a spike.   The problem may be one or other of
Printer Information  From HP specification for LaserJet 3200
Power consumption   135 watts  During Printing: At nominal line
voltage.      Model A (120V): Maximum of 700 W, Average of 210 W
Model AB (240V): Maxim