For the users who need to use modular UPS power supply, which parameter characteristics need to be attention? and which indicators must be met? For users, it can mainly be considered from six aspects including external characteristics, electrical performance, system design, ease of use design, manufacturing process and after-sales service.
Here we describe how to choose a suitable modular UPS power supply from external characteristics including volume, module weight, routing method, and cabinets parallel mode and etc.
- Volume:With the development of big data and cloud computing, data centers will become more and more centralized due to large-scale data computing and energy reduction. Therefore, the UPS is also required to have a smaller size, higher power density, and more flexible installation method. At present, the general modular UPS in market can support the power capacity of single cabinet more than 200kVA (about 0.5~0.7m2, excluding the distribution switch cabinet).
- System capacity:The system capacity is related to the module capacityand the number of modules that can be in parallel working. In theory, using the CAN bus scheme, up to 49 nodes can be connected to one CAN bus. However, considering the more modules in parallel, the logic is more complex. We recommend that number of modules in one unit of UPS system are no more than 20 pieces.
- Single modulecapacity/weight: At present, the power module capacityis available from 10kVA to 50kVA. Smaller module capacity means that more power modules will be used in the same online ups system capacity, and the system reliability will be reduced (control logic is complex, signal interference is increased, and system failures may occur due to the single module failures), but larger module capacity may result in insufficient redundancy or wasted capacity when the system capacity is low (such as 60kVA system capacity, if you use 50kVA modules, you must use two, and consider at least three for redundancy). Of course, if the overall system capacity is large, the high capacity modules can be selected. Generally recommend the module capacity is 20~40kVA, and the single module weight is less than 40Kg is better, it can be easily installed and maintenance.
- Installation method:The input and output lines of the UPS generally have two modeswhich are the lower cable mode and the upper cable mode (corresponding to the anti-static floor and the top cable tray). The user's actual use environment is changeable, in order to reduce the difficulty of work, the modular UPS should be required to support two types of cabling at the same time.
- System parallel capability:The modularUPS is the same as the normal tower UPS, the number of parallel units is also one of the factors to be considered. If the user have a need for expansion in the future, and the capacity of the single-system modular UPS is insufficient, the manufacturer should be required to provide a 3 phase high capacity UPS with parallel working capability. In order to improve the reliability of the parallel system, the parallel cable connection between the redundant parallel UPSs should be required at the same time. This can avoid the impact of a single point of failure on the system and the fault will not be enlarged. Whether the online UPS has parallel capability or not can be considered as one of the considerations for the design capability of the manufacturer.
- Cabinets combining methods: Modular UPS systemgenerally include power cabinets and power distribution cabinets (sometimes with bypass cabinets). Some manufacturers will sell the power cabinet and the power distribution cabinet as a whole, the twoparts cannot be disassembled independently (may use copper busbar connection, or the power distribution cabinet includes monitoring module and bypass module). Other manufacturers can provide integrated power cabinets,that is, a power cabinet that integrates monitoring, bypass, and partial power distribution functions, and can be sold as a stand-alone no break UPS. Users can choose the modular UPS according to actual needs.