1) Earthing of secondary circuits of SELV transformers (PELV circuits) is acceptable in general except when SELV is specifically required by the standard for a specific circuit (for example in whirlpool baths), in which case earthing of the secondary circuits are acceptable if:
SELV变压器的次级电路（PELV电路）的接地通常是可以接受的，除非特定电路的标准（例如在涡流浴缸）特别要求SELV，在这种情况下，如果满足以下条件，则次级电路的接地是可以接受的：
a) the accessible parts of the secondary circuits are separated from the protective earthing circuit by at least protective impedance, or
次级电路的可触及部分与保护接地电路之间至少要有保护阻抗分开，或者
b) the accessible parts of the secondary circuits are either directly connected to the protective earthing circuit or are protected against accidental contact by insulation as specified for Class III appliances or constructions, in particular the insulation shall be capable of withstanding a test voltage of 500 V AC for 1 min.
次级电路的可触及部分要么直接连接到保护性接地电路，要么通过针对Ⅲ类器具或结构规定的绝缘进行保护，以防止意外接触，尤其是绝缘应能够承受电气强度500 V AC 1 min。
Accessible parts directly connected to the protective earthing circuit shall comply with the requirements for protective earthing (see sub-clause 27.5) or shall be separated from live parts of the supply with insulation as specified for Class II construction.
直接连接到保护性接地电路的可触及部件应符合保护性接地的要求（见27.5条款），或应与电源的带电部件分开，并按II类结构的规定进行绝缘处理。
2. See also the following figure. 也见下图 | 
