Vertiv Liebert PSI5 Lithium-ion UPS 1500VA 1350W - PSI5-1500RT120LI - 2U RAC

Vertiv PSI5-1500RT120LI Lithium-Ion 1500VA Rack/Tower UPS

Overview

The Vertiv Liebert PSI5-1500RT120LI is a 1500VA / 1350W line-interactive UPS built around a lithium-ion battery — a meaningful engineering choice for rack environments where weight, footprint, and battery service life matter as much as runtime. At 2U, it fits comfortably in a standard 19-inch rack alongside the NVRs, PoE switches, and access control servers it's protecting. The line-interactive topology with automatic voltage regulation (AVR) keeps connected equipment on conditioned power without switching to battery for every minor grid fluctuation, which extends battery life and reduces wear on downstream hardware. If you're protecting a multi-camera surveillance head-end, a small server room UPS cabinet, or a network closet running critical access control infrastructure, the PSI5-1500RT120LI deserves a close look.

Explore the full Vertiv power protection catalog for additional capacity options and accessories in this line.

Key Features

• 1500VA / 1350W Lithium-Ion Platform: Lithium-ion chemistry delivers a longer service life and significantly lower weight compared to traditional VRLA batteries — useful in rack deployments where total weight budget matters and where you'd rather not schedule battery replacements every 3–4 years. The PSI5 line is built around this chemistry from the ground up, not retrofitted.
• Pure Sinewave Output on Battery: When the PSI5-1500RT120LI switches to battery, it produces a clean pure sinewave — not a simulated or stepped approximation. Active PFC power supplies in servers, NVRs, and managed switches require true sinewave input to operate correctly on battery; a modified waveform UPS can cause those loads to fault or generate excess heat. This matters if you're protecting any modern rack server or high-end NVR.
• Line-Interactive AVR (75–146VAC Input Range): The automatic voltage regulation handles input voltages from 75VAC to 146VAC without touching the battery. In facilities with sagging or swelling utility power — common in older buildings or areas with heavy HVAC loads — AVR keeps connected equipment stable and preserves battery capacity for actual outages. The nominal input is 120VAC.
• Selectable Output Voltage (100/110/115/120/125VAC): Output voltage is user-configurable to 100, 110, 115, 120, or 125VAC. This is useful when protecting mixed-voltage equipment or when dialing output to precisely match sensitive load requirements — particularly relevant for international hardware or legacy equipment running in a domestic rack.
• Front-Access Hot-Swappable Battery Kits: Battery replacement is done from the front of the unit without removing it from the rack or powering down connected equipment. In a live surveillance or access control environment, this is operationally significant — battery service doesn't mean a maintenance window.
• Rotatable LCD Control Panel: The LCD display rotates to remain readable whether the unit is installed in a rack (horizontal) or used as a tower (vertical). A small detail that becomes relevant when the unit ends up in a mixed-orientation server room or a field enclosure where tower orientation is more practical.
• Six 5-15R Output Receptacles: Six NEMA 5-15R outlets on a 5-15P input cord gives you clean, protected power for up to six devices without a PDU. For a typical small surveillance head-end — NVR, managed PoE switch, workstation — that's enough outlets to protect the full stack without additional hardware.
• 98.6% Efficiency: At 0.986 efficiency rating, the PSI5-1500RT120LI runs cool and wastes minimal energy as heat. In a sealed rack or small equipment room, lower heat dissipation reduces cooling load — a real operational factor over a multi-year deployment.
• USB + EPO + Optional IntelliSlot UNITY Card: USB connectivity is built in for local UPS management. An Emergency Power Off (EPO) connector is provided for integration with building systems. For SNMP and web-based remote monitoring, the optional Liebert IntelliSlot UNITY communications card slots in — enabling full network visibility into UPS status, load, and battery health without a separate monitoring appliance. This is where the PSI5 fits into enterprise power management workflows.
• UL 1778, c-UL-us, FCC Part 15 Class B Listed: UL 1778 (UPS standard) and c-UL-us listings cover the safety compliance bases for US and Canadian deployments. FCC Part 15 Class B means it meets residential and commercial EMI limits — relevant if the unit is in an office or customer-facing space rather than a dedicated machine room.

Integration & Compatibility

The PSI5-1500RT120LI fits into standard rack UPS deployments using a 2U form factor in a 19-inch rack. The NEMA 5-15P input cord plugs directly into standard 15A utility or PDU circuits — no special wiring required. USB management works with most UPS management software out of the box. For SNMP integration into a network management system (NMS) or enterprise power management platform, the IntelliSlot UNITY card is the correct path — it enables full SNMP/web monitoring and is sold separately. The EPO connector supports integration with building emergency power-off systems, a requirement in some data center and commercial facility deployments. As a rack or tower unit, it pairs naturally with managed PoE switches, NVR appliances, and access control servers that require conditioned, sinewave-quality power. Consult a UPS sizing and selection guide to confirm the 1350W capacity covers your specific load before deployment.

Frequently Asked Questions

Q: Does the PSI5-1500RT120LI produce pure sinewave output when on battery?

A: Yes. The PSI5-1500RT120LI delivers pure sinewave output on battery — not a simulated or stepped waveform. This is required for servers and devices with active PFC power supplies to operate correctly during an outage.

Q: Can the battery be replaced without powering down connected equipment?

A: Yes. The PSI5-1500RT120LI features front-access, hot-swappable battery kits. Battery replacement is performed from the front of the unit while connected loads remain powered — no maintenance window required.

Q: What input voltage range does the PSI5-1500RT120LI support?

A: The unit accepts input from 75VAC to 146VAC (nominal 120VAC) via its automatic voltage regulation circuitry. Within that range, it conditions power without switching to battery. Outside that range, it transfers to battery to protect connected equipment.

Q: Does the PSI5-1500RT120LI support SNMP monitoring?

A: SNMP and web management are not built in as standard — they require the optional Liebert IntelliSlot UNITY communications card. USB management is included standard. An EPO connector is also provided for building-level emergency power-off integration.

Q: Can the PSI5-1500RT120LI be used as a tower unit instead of rack-mounted?

A: Yes. The rotatable LCD control panel is specifically designed to remain readable in either rack (horizontal) or tower (vertical) orientation, and the unit supports both installation configurations.

Q: What output voltage options are available on the PSI5-1500RT120LI?

A: Output voltage defaults to 120VAC and is user-selectable to 100, 110, 115, or 125VAC to accommodate mixed-voltage equipment or specific load requirements.

Eden Phillips

The PSI5-1500RT120LI is one of the more deployment-practical rack UPS units I've worked with at the 1500VA tier — specifically because of the front-access hot-swap battery design combined with the lithium-ion chemistry. Most integrators encounter the battery service problem when it's too late: the batteries in a 3-year-old rack UPS are degraded and replacement means shutting down the NVR or the access control server during business hours. The PSI5 eliminates that problem entirely. The 98.6% efficiency rating also means this unit runs noticeably cooler than traditional VRLA-based competitors at similar wattage — relevant in equipment closets where you're already fighting heat budgets.

Technical Highlights:

• Pure Sinewave on Battery: 1350W of clean sinewave output protects modern NVRs and servers with active PFC supplies — modified waveform UPS units can cause these loads to fault or run hot on battery; the PSI5 avoids that entirely.
• 75–146VAC Input AVR Window: The wide automatic voltage regulation range means the unit stays on utility power through brown-downs as low as 75VAC, preserving battery for genuine outages rather than burning cycles on everyday voltage sag.
• IntelliSlot UNITY Expansion: The optional communications card slot enables full SNMP/web management integration — the right path for any deployment where the UPS needs to be visible in a network management system or trigger graceful shutdown scripts on protected servers.

Deployment Considerations:

• SNMP monitoring requires the IntelliSlot UNITY card as a separate purchase — budget for it upfront if remote monitoring or automated shutdown is in scope for the project.
• The unit ships at 28.4 lbs; lithium-ion is lighter than equivalent VRLA UPS units but still requires proper rack rail support — verify your rack rail kit is rated for the weight before installation.

The PSI5-1500RT120LI is the right specification for small-to-mid surveillance head-ends and network equipment rooms where the combination of hot-swap battery service, sinewave output quality, and future SNMP integration justify the lithium-ion platform over a basic VRLA alternative.