Intel ATX12V manual Safety, North America

ATX12V Power Supply Design Guide

Version 2.0 Final Review Copy

8. Safety

The following subsections outline sample product regulations requirements for a typical power supply. Actual requirements will depend on the design, product end use, target geography, and other variables. Consult your company’s Product Safety and Regulations department for more details.

8.1. North America

The power supply must be certified by an NRTL (Nationally Recognized Testing Laboratory) for use in the USA and Canada under the following conditions:

•The supply must be recognized for use in Information Technology Equipment including Electrical Business Equipment per UL 60950, 3rd edition, 2000. The certification must include external enclosure testing for the AC receptacle side of the power supply. (see Figures 8 and 9).

•The supply must have a full complement of tests conducted as part of the certification, such as input current, leakage current, hi-pot, temperature, energy discharge test, transformer output characterization test (open-circuit voltage, short-circuit current, and maximum VA output), and abnormal testing (to include stalled-fan tests and voltage- select–switch mismatch).

•The enclosure must meet fire enclosure mechanical test requirements per clauses 2.9.1 and 4.2 of the above-mentioned standard.

Production hi-pot testing must be included as a part of the certification and indicated as such in the certification report.

There must not be unusual or difficult conditions of acceptability such as mandatory additional cooling or power de-rating. The insulation system shall not have temperatures exceeding their rating when tested in the end product.

The certification mark shall be marked on each power supply.

The power supply must be evaluated for operator-accessible secondary outputs (reinforced insulation) that meet the requirements for SELV and do not exceed 240 VA under any condition of loading.

The proper polarity between the AC input receptacle and any printed wiring boards connections must be maintained (that is, brown=line, blue=neutral, green or green/yellow=earth/chassis).

Failure of any single component in the fan-speed control circuit shall not cause the internal component temperatures to exceed the abnormal fault condition temperatures per IEC 60950 3rd ed., 1999.

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