Modular UPS System

A modular UPS protects servers, storage, network equipment and cooling controls in data centers, telecom rooms, hospitals and industrial sites. It converts incoming AC power to DC, charges the battery, and converts DC back to clean AC, so the load rides through outages, sags, surges and frequency changes.

The modular design lets the UPS grow with the load. Start with two or three power modules and add modules as the IT load increases. Failed modules can be replaced while the UPS continues to supply the load, which reduces downtime and spare-parts planning.

The system capacity ranges from 50 kVA to 1,200 kVA. Each power module is typically 50 kVA or 100 kVA, and the frame accepts 4 to 12 modules depending on the model. A 200 kVA frame with four 50 kVA modules can run N+1 with three modules carrying the load and one module as standby.

Redundancy is configured as N+1, N+2 or 2N. N+1 is common for commercial sites; 2N is used for critical data centers and hospitals. The UPS can also be paralleled with a second frame for higher capacity or dual-bus architecture.

Double-conversion efficiency is typically 95% to 96% at full load, with an ECO mode around 99% for stable grids. Input power factor is above 0.99 with low THDi, so the UPS does not distort the building supply. Output power factor is 1.0, which means 100 kVA supports 100 kW of modern IT load.

The inverter supplies a pure sine wave with tight voltage and frequency regulation. Overload capability is typically 110% for 60 minutes, 125% for 10 minutes and 150% for 1 minute. Confirm the overload curve and the bypass configuration for the project.

Battery options include VRLA blocks in a dedicated cabinet and lithium iron phosphate racks. Runtime is usually sized for 10 to 30 minutes at full load, or for the time needed to start a generator and transfer the load. Lithium batteries take less space and have a longer cycle life; VRLA has a lower first cost.

Battery management includes temperature compensation, periodic self-test, and alarms for low voltage and open cells. For long runtime, use an external battery cabinet and confirm the room floor loading and ventilation.

The UPS frame needs front and rear access for module replacement, typically 1,000 mm in front and 800 mm at the rear. Room cooling must remove the UPS losses: at 96% efficiency, a 200 kVA UPS with 160 kW load produces about 6.7 kW of heat. Keep the battery room within the manufacturer's temperature range.

Typical lead time is 30 to 45 working days after drawing approval, depending on the frame, module count and battery configuration. Site work includes cable termination, battery installation, commissioning and load-bank testing.