This regulation applies to the secondary circuitry. The circuit should be designed to guarantee that under normal operating conditions, the voltage between any two touchable points should be less than 42.4Vpeak or 60Vdc. For class I equipment, it refers to "between any touchable point and the ground." Under single fault conditions, the voltages between any two conductors of the SELV circuit and between any one such conductor and earth shall not exceed 42.4V peak or 60Vdc for a period longer than 0.2 seconds. Moreover, a limit of 71V peak or 120Vdc shall not be exceeded. According to requirements below, MW SPSs can comply with SELV. IEC 60950-1 (ITE SPS): voltage of o/p circuit is less than 60Vdc under normal condition. IEC 61347-2-13 (LED SPS): voltage of o/p circuit is less than 120Vdc under normal condition.