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UPS Sizing
How to Size a UPS System
It’s important to know how to size your UPS. Whether single or three-phase, there are several important factors to consider when correctly sizing your UPS system. At any time you can consult our Technical Consultants to help you with this via chat, call, or email. We discuss your situation and recommend an appropriate system whether Single Phase or 3 Phase.
Power Factor (PF) is the ratio of working power to apparent power, or the formula PF = kW / kVA. A high PF benefits both the customer and utility, while a low PF indicates poor utilization of electrical power.
kW (kilowatts) or Working Power – the “true” or “real” power used in all to perform the work of heating, lighting, motion, server function, etc.
The equipment used in a data center will list its kW rating on the UL listing plate. You should average or keep in context the cumulative power factor of your data center loads to properly size the UPS system.
UPS Power and Internal UPS Loss
UPS system internal power loss as well as the additional power required for battery charging. UPS efficiency varies between product models and varies dramatically depending on the loading of the UPS.
UPS are rarely run at the operating points where their advertised efficiency is provided. A realistic and sufficiently accurate value for UPS efficiency in a typical installation is 88%. Battery charging is a significant but intermittent power consumer.
Under normal operation with a charged battery the battery charging load is negligible. However, when a battery has been partially or completely discharged the battery charging power can be on the order of 20% of the rated UPS load. Although this load only rarely occurs, the generator and service entrance must be sized for this load.
These additional power requirements contribute to the oversized input breakers required for UPS systems upon installation. Load, plus, inefficiency, overload capability, and also the charging of the battery contribute to overall input breaker sizing.
The UPS must be able to handle full load while also charge the battery system post an electrical outage.
Single Source UPS Provider
It’s important to know how to size your UPS. Whether single or three-phase, there are several important factors to consider when correctly sizing your UPS system. At any time you can consult our Technical Consultants to help you with this via chat, call, or email. We discuss your situation and recommend an appropriate system.
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We Can Help Answer Any Unanswered Questions
Experienced Product Representatives are on hand to send you information and quotations for equipment. If you need help with sizing, installation planning, or general questions about products, please fill in the appropriate form below and someone will contact you shortly.
You may also call 844-501-1887 to get a direct product representative. Or you may chat with one of our product specialists in the chat box provided.
