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Based on this answer to the question "Why shouldn't I attach laser printers or scanners to a UPS?", and a comment made by Blunder, should you plug a printer directly into a wall socket and avoid plugging it into a surge protector?

When turned on, Laser printers draw a very high current to heat up their fuser roller. their current draw can go from 0 to 20A in milliseconds. A typical UPS cannot cope with such a spike.

The problem is this inrush current at start-up, not the normal operating current. The inrush current can be seven times the normal operating current of the printer.

As a surge protector aims to limit sudden spikes in voltage, it would seem that a surge protector would restrict this inrush current, as increased current would cause a higher potential difference in voltage.

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up vote 5 down vote accepted

Surge protectors are designed to protect the equipment from voltage surges in the supply, typically they block or divert the supply at voltages over 3xnominal (e.g. at 330V on a normally 110V supply).

The typical threat is a lightning strike on the power line nearby. "An average bolt of negative lightning carries an electric current of about 30,000 to 100,000 amperes (30-100 kA) at a voltage of over a billion volts." (Wikipedia) Of course this is much reduced by the time any voltage surge reaches your surge protector but this is the type of event for which surge protectors were intended.

A Laser printer, or other device, drawing a very high current (20-40 A) for 10-20 mS will not cause a voltage RISE in the supply, it is more likely to cause a short-duration voltage DROP in the supply (e.g. from 110 V AC to 90 V AC)

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+1, completely neglected to think about how potential differences actually work in regards to the power supply. – ardentsonata Aug 27 '12 at 18:45

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