5.5 Spacings and separation of circ

5.5 Spacings and separation of circuits5.5.1 Electrical circuits within the pack at opposite polarity shall be provided with reliable physical spacing to prevent inadvertent short circuits (i.e. electrical spacings on printed wiring boards, physical securing of un-insulated leads and parts, etc.). Insulation suitable for the anticipated temperatures and maximum voltages shall be used where spacings cannot be controlled by reliable physical separation.5.5.2 Electrical spacings in circuits shall be based upon the grade of insulation required as outlined in the Grade of Insulation section of the Standard for Information Technology Equipment – Safety – Part 1: General Requirements, UL 60950-1, and shall comply with the creepage and clearance requirements of the Clearances, Creepage Distances and Distances Through Insulation section of the Standard for Information Technology Equipment – Safety – Part 1: General Requirements, UL 60950-1 for the appropriate pollution degree of the intended environment (see the Pollution Degrees section of the Standard for Information Technology Equipment – Safety – Part 1: General Requirements, UL 60950-1). Exception No. 1: As an alternative to these spacing requirements, the spacing requirements in the Standard for Insulation Coordination Including Clearances and Creepage Distances For Electrical Equipment, UL 840, may be used. For determination of clearances, a dc source such as a battery does not have an overvoltage category as outlined in the section for Components of the Standard for Insulation Coordination Including Clearances and Creepage Distances For Electrical Equipment, UL 840 unless charged through an ac mains connected rectifier, then the overvoltage category should be the same as that required for the rectifier unless the rectifier uses galvanic isolation. If galvanic isolation is employed, then the overvoltage category can be reduced to the next lower overvoltage category. The anticipated pollution degree is determined by the design and application of the electrical energy storage system or subassembly under evaluation