Joe,
As mentioned by Hutch, there are a few situations which arrise when using Equipment built for one certain Frequency on a higher or lower Frequency.
I'll briefly cover some stuff here.
***Induction Motors [Squirrel Cage Rotor & Wound Rotor]: Full-Load RPMs are effected on these Motors. The most obvious change in speed will be seen on Motors with a "Set Speed".
A simple example: Two Pole Squirrel Cage Rotor Induction Motor. 1 HP - 3,450 RPM @ 60 HZ [Rotor speed slips to apx. 3,450 RPM when developing maximum HP].
No Load RPM @ 60 HZ = 3,600 RPM
At 50 HZ, no load RPM = 3,000 RPM, and slips to somewhere around 2,895 RPM at full load.
Same applies in reverse when HZ is increased.
An Induction Motor's speed is related to the Syncronous Frequency.
So to make an Induction Motor run at 1/2 speed [1800 RPM instead of 3600 RPM], the poles are doubled. 3600 RPM for 2 pole motor, 1800 RPM for 4 pole motor.
These are very basic examples for Induction Motors. Many other examples and factors have not been shown, but are important to the overall performance and design.
***Syncronous Motors: These should run at the Line Frequency of the Power System which they are connected to. Once again, design per anticipated HZ will be a key issue.
***Incandescent Lamps: No changes in output should be seen. If the HZ falls to like 25 HZ and lower, there may be noticable flashing from dips in light intensity while current passes the "Zero Line"
***Ballasts: Lamps running at Line HZ may show higher flickering / pulsing when driven at lower frequencies. Ballasts may tolerate slight HZ variations, but should be used on Frequencies which they are designed for. [see transformers]
***Transformers: Transformers may be used between 50 HZ and 60 HZ without too much of an effect - provided they are lightly used. Voltages will be mostly effected.
As with all Inductive items, the lower frequency results in larger cores / windings.
Reactances [XL for Inductive Reactance, XC for Capacitive Reactance, "X" for Total Reactance] change with Frequency.
This can be a really lengthy and in-depth discussion, so I'll stop here!.
***Switch-Mode Power Supplies: These usually Rectify the input AC to Pulsating DC, so in the most point they shouldn't be effected.
Sure hope this answers your questions!
Scott s.e.t.
