UL 1261-2016 pdf download – Electric Water Heaters for Pools and Tubs.
2.1 1 CONTROLLED ENVIRONMENT – An environment that is relatively free from conductive contaminants, such as dust and carbon particles, and that is protected against humidity and condensation. A controlled environment may be provided by a hermetically sealed enclosure, encapsulation, or a conformal coating. 2.1 2 HOT TUB – A tub intended for partial or total immersion of persons in heated water. 2.1 3 LOW-VOLTAGE CIRCUITS – A low-voltage circuit is one involving a potential of not more than 30 volts rms (42.4 volts peak) supplied by a primary battery, by a standard Class 2 transformer, or by a combination of a transformer and a fixed impedance that, as a unit, complies with all of the performance requirements for a Class 2 transformer. A circuit derived from a source of supply at line voltage by connecting resistance in series with the supply as a means of limiting the voltage and current is not considered to be a low-voltage circuit. 2.1 4 OPERATING TEMPERATURE VALUE – Value of temperature at which the temperature sensing control operates on a rise or fall of the temperature. 2.1 5 SAFETY CRITICAL FUNCTION – Control, protection and monitoring functions which are being relied upon to reduce the risk of fire, electric shock or casualty hazards. 2.1 6 TEMPERATURE SETTING BY THE USER – Any selection of an operating temperature value by actuation performed by the user. 3 Safety Critical Functions 3.1 Any function involved in the control, protection, and monitoring of safety-related attributes of a unit whereby a loss/malfunction of its functionality would represent an unacceptable risk of fire, electric shock, or casualty hazards would be considered a Safety Critical Function.
4.5 Boxes and raceways 4.5.1 Electrical boxes and the associated bushings and fittings, and raceways, of the types specified in Chapter 3, Wiring Methods and Materials, of the National Electrical Code, ANSI/NFPA 70, and that comply with the relevant UL standard (such as the Standard for Metallic Outlet Boxes, UL 51 4A, the Standard for Nonmetallic Outlet Boxes, Flush-Device Boxes, and Covers, UL 51 4C, the Standard for Cover Plates for Flush-Mounted Wiring Devices, UL 51 4D) are considered to comply with the requirements of this end product standard. 4.6 Overcurrent protection 4.6.1 Fuses shall comply with the Standard for Low-Voltage Fuses – Part 1 : General Requirements, UL 248-1 ; and the applicable Part 2 (e.g. UL 248-5). Defined use fuses that comply with UL 248-1 and another applicable UL standard for fuses are considered to comply with this requirement. 4.6.2 Fuseholders shall comply with the Standard for Fuseholders – Part 1 : General Requirements, UL 4248-1 , and the applicable Part 2 (e.g. UL 4248-9). 4.6.3 Circuit breakers shall comply with the Standard for Molded-Case Circuit Breakers, Molded-Case Switches and Circuit-Breaker Enclosures, UL 489. Exception: Circuit breakers used in telecommunications circuitry that comply with the Standard for Circuit Breakers For Use in Communications Equipment, UL 489A, need not comply with the Standard for Molded-Case Circuit Breakers, Molded-Case Switches and Circuit-Breaker Enclosures, UL 489. 4.6.4 Circuit breakers having integral ground fault circuit interrupter capability for protection against electrical shock shall additionally comply with the Standard for Ground-Fault Circuit-Interrupters, UL 943. 4.6.5 Supplementary protectors shall comply with the Standard for Supplementary Protectors for Use in Electrical Equipment, UL 1 077.