Dahua PFM3355-1000L 1 kVA 900 W Online Rackmount UPS

Unlike line-interactive or standby units, a double-conversion UPS constantly converts incoming AC to DC and back to AC. Your connected equipment always runs from the inverter, so it is isolated from voltage sags, surges and frequency fluctuations on the mains. When the grid fails, there is no transfer switch to flip, which means workstations, storage and network gear keep running without the brief interruption that can crash sensitive hardware.

The PFM3355-1000L delivers a pure sine waveform, matching the clean power that modern devices are designed for. This matters for workstations with active PFC power supplies, which can behave unpredictably or shut down on simulated sine wave output. Clean output also helps reduce unnecessary heat and noise in connected power supplies, making this UPS a sensible choice for professional computers, NAS units and networking equipment.

With a rating of 1 kVA and 900 W of active power, this UPS has headroom for a typical workstation with a monitor, or a compact set of network devices. The high ratio between watts and volt-amperes means more of the rated capacity is actually usable by modern equipment. To size your setup correctly, add up the real power draw of every connected device and keep the total below 900 W.

Three output sockets let you connect the essentials directly: for example, a workstation, a display and a router or switch. Keeping the protected load limited to critical devices helps you get the most out of the battery during an outage. The manufacturer does not list the outlet type in the specifications provided, so check that your power cables match before installation.

The rackmount form factor allows the unit to sit neatly in a standard equipment rack alongside servers, switches and patch panels, keeping cabling organised and freeing up desk or floor space. The black and grey finish blends in with typical rack hardware. The rack height in units and the physical dimensions are not listed in the specifications, so confirm available space in your cabinet beforehand.

This online UPS is aimed at small offices, IT administrators, video surveillance installers and professionals running workstations that must stay powered through grid disturbances. It suits rack-based setups where clean, uninterrupted power is more important than maximum outlet count. If you need to protect a single critical machine or a compact network stack in a rack, its online topology and pure sine output cover the core requirements.