25. A periodic supervision is required for the operation of the following protected installations by the protective devices provided for in section 10:(a) multiple installations for which the total capacity exceeds the maximum capacity established for conditional supervision without exceeding the maximum capacity established for periodic supervision as indicated in Schedule C;
(b) mixed installations that, according to section 9, require a periodic supervision;
(c) steam engine and turbine installations over 250 kW, even if they are included in a mixed installation requiring a more rigid supervision; and
(d) refrigerating apparatus of 7.5 kW or less that are part of a mixed installation requiring a more rigid supervision. In that case, despite section 10, these apparatus are considered protected if they are equipped with a high pressure limit control as well as with a low pressure limit control.