Is your appliance compatible with the voltage used in Guam (110V)?
If your appliance is not compatible with multiple voltages, you will need a transformer to adjust the voltage input when using your appliance in Guam.
Frequency of Electrical Current
The frequency of electrical current found in Andorra (50Hz) differs to that found in Guam (60Hz).
Most equipment is not affected by differences in frequencies. Some exceptions are:
Electric clocks: Some electric clocks use the frequency of electrical current to measure time. If the clock is designed for one frequency, but used with another, time shifts could be experienced.
Appliances using motors: If there is a motor load associated with an appliance, the frequency governs the speed in revolutions of the motor. This could mean that the motor will spin faster, or slower than intended and could have a detrimental effect in the appliance's operation. This is of particular concern in power tools and other machinery that uses motors, so if you must use these, you should seek access to a frequency converter.