Operation on two phases of a 3-phase system

No external protective devices are required to protect against phase failure.

This power supply can also be operated continuously on two strings of a 3-phase system. However, it is not recommended for this capacity class, since the feeding 3-phase network can become unbalanced.

When operating on only two strings of a three-phase system, the output power must be reduced according to the curves below. Exceedance of these limit values over extended periods leads to thermal shutdown of the system.

This kind of operation is not covered by the UL approval. Additional testing may be required if the complete system has to be approved according to UL 508 or UL 60950-1.

Make sure the EMC performance, hold-up time and losses are different from three-phase operation. Therefore check the suitability of your individual application.