1.1 This part of IEC61534 specifies general requirements and tests for powertrack (PT) systems with a rated voltage not exceeding 277V a.c. single phase, or 480V a.c. two or three phase 50Hz or 60Hz with a rated current not exceeding 63A. These systems are used for distributing electricity in household, commercial and industrial premises. 1.2 Powertrack systems, according to this standard, are intended for use under the following conditions: an ambient temperature in the range—5°C to+40°C, the average value over a 24h period not exceeding 35°C; a situation not subject to a source of heat likely to raise temperatures above the limits specified above; an altitude not exceeding 2000m above sea level; an atmosphere not subject to excessive pollution by smoke, chemical fumes, prolonged periods of high humidity or other abnormal conditions. In locations where special conditions prevail, as in ships, vehicles and the like and in hazardous locations, for instance, where explosions are liable to occur, special constructions may be necessary. This standard does not apply to cable trunking systems and cable ducting systems covered by IEC61084 [8] 1 ; busbar trunking systems covered by IEC60439‑2 [5] ; electrical supply track systems for luminaires covered by IEC60570 [6] .