Overview
Apple products that can be used outside of their country of purchase can be categorized into three classes: those that accept a range in voltage, those that accept a range in frequency, and those that accept a range in both voltage and frequency. Knowing the power requirements of a specific product and the characteristics of the electrical power in the foreign location where you plan on using it will help you to determine if you can use your Apple product there.
Universal
These products can be used internationally out of the box. Some of Apple's products are self-configuring devices or "universal" within a certain range. They can accept a range in both voltage and frequency, and only require a plug adapter for the specific locale.
Example: The Apple Power Macintosh G3 accepts 100 V to 240 V, 50 Hz to 60 Hz.
Frequency Independent
These products can be used internationally with a voltage transformer. Generally, they are designed for 120 V power, but are flexible as to the frequency they accept (for example, 47 Hz to 63 Hz) They are known as "frequency independent." These products require a step-down isolation transformer to adapt the voltage, but handle the different frequency on their own.
Example: The North American Apple LaserWriter 8500 accepts 100 V to 120 V, 50 Hz to 60 Hz.
The Apple LaserWriter 8500 uses a switching power supply that works independently of the input frequency. The European and Australian input frequency standard of 50 Hz do not adversely affect this printer. You can use the Apple LaserWriter 8500 overseas with a voltage converter (isolation transformer).
Frequency Dependent
These products generally cannot be used internationally because they only work within a narrow range in frequency. They are "frequency dependent." Transformers or converters only transform voltage, so if the product requires a certain frequency, there's no practical way to convert both voltage and frequency.
These products can be used internationally only in countries with the same frequency as the country for which the product was manufactured. Further, a voltage transformer is required if the destination country has a voltage different from the home country.
Example: The North American Apple Color StyleWriter 2500 accepts 120 V, 60 Hz.
Important: Desktop computers with power outlets for peripherals do not condition the voltage as it passes through. So, a monitor requiring 120 V, 60 Hz power cannot be used in a 220 V, 50 Hz environment even if the computer from which it gets its power is able to accept the local power.
Apple Products
Universal Devices
The majority of Apple's products manufactured after the Macintosh SE (1987) are self-configuring or "universal" between 100 V and 240 V, 50 Hz to 60 Hz. Usage in countries within these ranges may only require a plug adapter. Note that some Apple products have a voltage selector to select between 110 V and 220 V. For these products, you must select the correct voltage before plugging them in.
To verify if a specific product is universal, check its label for the voltage and frequency requirements, or the Apple Spec Database at
http://www.info.apple.com/applespec/.
Voltage-Dependent Devices
The Apple products designed to operate at a line voltage ranging from 107 V to 137 V at 50 Hz or 60 Hz (cycles per second) are considered to be voltage-dependant. If the destination country uses a line voltage of 220 V, and the product only accepts 120 V, you'll need a 220 V to 110 V stepdown isolation transformer. This type of transformer is the only one known to give a clean signal.
The transformer's wattage should be 150 percent of the total wattage of the system (computer, monitor, hard disk, printer, and so forth). For example, if the system consumes 250 W of power, use a transformer rated for a minimum of 375 W. A 500 W transformer should be sufficient for an entire Apple system (computer, monitor, and printer). It must also have a third prong for a grounded outlet. Electrical shock to you, or damage to the hardware may occur if the products are not correctly grounded.
Non-universal Apple power supplies function correctly with voltages between 107 V and 132 V. If line voltage fluctuates outside these specifications, you need to use a power conditioner to ensure uninterrupted operation of your Apple equipment. Operating without the conditioner will probably not result in damage to the hardware, although the voltage fluctuation may cause your computer to be unresponsive. In such an event, you will lose any data in memory and may even lose data stored on disk.
Frequency-Dependent Devices
If the country uses a line frequency other than 60 Hz, then all AC-powered devices attached to your computer system (monitors, printers, and so forth) must be "frequency independent." That is, they must be able to operate on a line frequency of either 50 Hz or 60 Hz. A majority of Apple products are frequency independent, but check the specifications of all equipment prior to using it.
Traveling Tips
When traveling with a computer, protect it from shock, heat, moisture, radiation, and theft. Special hard-shell shipping cases are advertised for most Apple products. These cases can protect computer products from environmental abuse. In addition, they often do not look like computer cases, and usually escape the notice of thieves.
X-rays and other magnetic radiation associated with X-ray machines only pose a slight potential danger. Most airports X-ray all luggage. If the risk in losing software or data is too high, back the files stored on your computer's hard disk.
Due to concern about computers and floppy disks going through security scanners at airports, the American Society for Testing and Materials (ASTM) conducted a study on X-ray induced damage to memory devices, including audio and video tapes and floppy disks. They found that the devices usually have enough shielding to protect the media. The study found that the magnetic field was actually strongest around the scanner's monitor. They taped a disk to the monitor for several hours without damage. A committee member suggested that it would take at least 1000 million passes through the machine before any damage would be evident.