Which standard is not directly associated with electric heaters?

The correct choice is associated with standards that specifically govern electric heating equipment. The standard in question, UL 2200, is focused on the performance and safety requirements for stationary generators and is not specifically intended for electric heaters.

In contrast, UL 726 pertains to electric duct heaters, emphasizing safety and performance in heating applications. UL 1261 relates to electric baseboard heaters, while UL 875 addresses electric heating cables. These standards are all tailored to ensure the safety and quality of various electric heating devices, which is why they are applicable to electric heaters.

Understanding the purpose of each standard helps in identifying that UL 2200 does not directly apply to electric heating units, as its focus is elsewhere in the realm of electrical equipment safety. This differentiation is crucial for compliance and safety assessments in mechanical installations involving electric heaters.