UPS 380VAC output provides single-phase power
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I would like to ask: Can a UPS with 380VAC/60KVA input and output be used for a DCS system, which requires 220VAC power supply? Will it work if only one phase is connected? What will be the consequences of that? As long as it’s not overloaded, is that okay? The DCS capacity should not exceed 60KVA. Thank you for your advice! !
If the power is not high, it is acceptable to use only one phase, resulting in an output of 220VAC; however, this approach is not recommended for higher power levels, to avoid imbalance in the three-phase circuit. If there are many electrical devices in the instrument room, it is possible to feed each phase as a single-phase circuit; it is best to calculate the load for each circuit to achieve a roughly balanced distribution.
Ahaha, I’ll reply to this sea friend! Regarding your company’s estimate that the UPS power required for the DCS power supply is around 60 KVA, it is generally not recommended to use a UPS with three inputs and three outputs. It is suggested that you opt for a UPS with three inputs and one output, operating at 380/220 V. Many imported and joint-venture brands offer UPS units of this power rating; for example, Eaton’s 9EHD series (10–100 KVA) and Emerson’s iTrust Industry series both have models available in the 60 KVA range! If the original poster insists on using it, the load of the DCS system must be distributed evenly across the three phases; only by achieving a balanced distribution can it work properly ； Otherwise, if only one phase is connected, it will cause severe three-phase imbalance in the UPS output. This is a mode of operation that the UPS does not allow, as it severely affects the reliable operation of the UPS and can even lead to frequent failures; such a situation must be avoided!
A three-phase switch with several single-phase switches attached to it can be used
I’ve learned it! The consequences of three-phase imbalance seem quite severe.