Do phase converters make a noise and where should I put mine?
Most phase converters should be installed in dry locations where there is no possibility of water spraying or dripping into them, or should be designed with an enclosure suitable for outside installation. Ideally they should not be located where metal shavings or metal dust collect for obvious reasons. Because of static, dust and wood shavings do tend to accumulate internally, especially in bakeries and carpentry shops, but we have yet to observe a unit that has actually failed due to this.
Static phase converters make very little noise (just a transformer hum) whereas rotary phase converters will make the same noise as an unloaded motor, i.e. the rush of air through the motor fan and a limited amount of mechanical vibration. The three ways to overcome this noise are to enclose the motor in a cabinet, to mount the motor on anti-vibration mountings, and to install the entire converter in a separate enclosure with sufficient ventilation - under stairs, in the roof space, or in a lean-to are the most common. We have not seen any scientific noise measurements given by any manufacturer.