UL 1434:2021 PDF Download

1.1 These requirements apply to discrete thermistor-type devices constructed of ceramic or polymeric semiconductor material.

1.2 These thermistors are intended for use as:

1. a) Self-limiting devices such as heaters;

2. b) Control devices such as current limiters and inrush-current limiters; or

3. c) Sensing devices.

1.3 These requirements apply to positive temperature coefficient (PTC) and negative temperature coefficient (NTC) type devices.

1.4 Control devices, such as current limiters are not intended to replace current interrupting devices such as fuses, but are intended to provide a level of overcurrent protection complying with the end-use equipment requirements.

1.5 These requirements do not apply to heating cables, such as self-regulating pipe heating cable, that are constructed with thermistor-type material.

1.6 Deleted