The safety of power supplies to computers at home has come under scrutiny in the wake of recent fire accidents involving faulty computer battery.
With safety as the main concern, the Consumer Council has undertaken a test of 20 models of computer power supplies comprising 14 of the ATX and micro ATX types suitable for do-it-yourself assembling of own personal computers, and 6 notebook types.
In the test, a few of the samples were shown to be of particular safety concern, namely, the 2 universal models which fit most notebooks of major brands.
The samples were found to overheat substantially even in the claimed normal output power. Though the overheating is not deemed serious enough to warrant any concern for fire hazard, consumers are strongly urged to be extra cautious in the use of such device.
Many components of these 2 models were found overheated in excess of the temperature limits of the safety standard. In addition, the plastic enclosures were deformed in a heat resistance test with live parts becoming accessible.
In one model, the enclosure material softened severely in another heat resistance test, the ball pressure test. In the other, the insulation broke down when a test voltage was applied across the input and the output, posing risk of electric shock if one touches the output when faults arise.
Further, many of the computer power supply samples were found to grossly overclaim their related power output, posing risk of overloading.
Only 6 of the ATX/micro ATX samples were up to their claimed power output. The worst sample could deliver only about half of its claimed capacity.
Other safety deficiencies detected in ATX models include: insufficient insulation distances, overheating for transformers and inductors, poor earthing and inadequate wiring fixing, missing or insufficient marking.
As many of the portable electronic devices are recharged via the USB ports of the computer, users were cautioned not to plug in too many peripherals at the same time to avoid overloading of the computer power supply. It might affect normal operation of the computer.
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