Deals with the safety of electric heat pumps, including sanitary hot water heat pumps, air-conditioners, and dehumidifiers incorporating sealed motor-compressors and hydronic room fan coils. The maximum rated voltage being not more than 250 V for single phase and 600 V for all other appliances. The referenced appliances may consist of one or more assemblies. If provided in more than one assembly, the assemblies are to used together, and the requirements are based on the use of matched assemblies. Supplementary heaters, or a provision for their seperate installation, are within the scope of this standard, but only heaters which are designed as a part of the appliance package, the controls being incorporated in the appliance.