CAN/CSA-C22.2 No.225-M90

1.1 Applies to equipment intended to be electrically connected to a telecommunication network and receives its power from the telecommunication network alone, or from an ac or dc source, or from any combination thereof. The network has a normal operating voltage to ground of less than 150 V rms and the equipment is designed to be operated in nonhazardous locations in accordance with the Canadian Electrical Code, Part I. Notes: (1) In some existing telecommunication networks, the rms value of 150 V may be exceeded during alerting. (2) An ac or dc power source includes an ELV power supply. 1.2 This Standard applies to equipment intended to function at telecommunication network operating voltages of less than or equal to 56.5 V dc with a source impedance of 300 to 1600 (ohms), recognizing that alerting and test voltages higher than 56.5 V are generally intermittent and will normally be present over a small proportion (less than 1%) of the usage of the equipment. 1.3 This Standard is concerned solely with the requirements for safety from electrical shock, energy hazards, electrical fire hazards, and related thermal and mechanical hazards, including acoustic shock. 1.4 This Standard applies to cordless telephones that are powered by Class 2 circuits but does not apply to cellular radio telephones and other radio receive/transmit type systems. In addition, this Standard may not apply to equipment that may be electrically connected to a telecommunication network and which is covered by any other Standard which addresses this network interfacing. 1.5 This Standard does not apply to electrical equipment that electrically connects with a telecommunication network but whose primary function is other than telecommunication.