Scalable runtime and continuous protection

Unlike compact UPS systems with fixed internal batteries, the P91g supports up to eight matching external battery packs to align runtime with application requirements. Online double-conversion topology ensures connected equipment is continuously powered by conditioned output, independent of upstream disturbances; during outages, the system maintains zero transfer time while sustaining load from battery energy. A high-capacity charger (up to 12 A) recharges large battery strings quickly — supporting both short-duration ride-through and extended-runtime strategies across distributed deployments.

What the P91g delivers

The global 208/230V online runtime platform

The P91g operates as the standard 208/230 V online UPS platform within distributed power architecture, balancing power conditioning with runtime scalability. It is typically deployed at the rack or closet level for localized protection, in multi-site environments requiring standardized platforms, and alongside downstream PDUs for distribution and control.

Choose the P91g for 208/230 V online protection with VRLA runtime scaled per deployment and the lowest upfront cost; step up to lithium (P91g Li or J90i) for reduced maintenance and longer lifecycle, or choose the P91 for the 120 V version of this platform.

P91g (VRLA) or lithium?

The P91g is a VRLA-based platform optimized for runtime scalability and lower upfront cost — selected when external battery expansion and cost structure are prioritized over lifecycle optimization. Lithium platforms such as the P91g Li and J90i prioritize reduced maintenance, higher temperature tolerance, and longer lifecycle. Both deliver full-time online conditioning; the choice comes down to runtime strategy and total cost of ownership.

Replace legacy APC / Eaton 230V online UPS

The P91g is commonly deployed as a replacement for legacy compact online platforms — APC Smart-UPS Online (SRT), Eaton 9130 and early 9PX, and Vertiv Liebert GXT systems — providing a modernization path with full real-power output, higher charging capacity, and scalable runtime architecture.

P91g-3000 vs the field at 3 kVA

The differences are clearest at a single capacity. Here is the P91g-3000 against the 3 kVA online platforms it most often replaces, drawn from the per-model comparisons. The 1.5 and 2 kVA matchups follow the same pattern — full breakdowns are in the comparison hub.

The P91g-3000 leads on usable watts vs APC, a faster programmable charger, lighter weight, higher altitude tolerance, and standard TAA compliance. APC supports more battery packs (10 vs 8); Eaton and Vertiv support fewer (4 and 6). All P91g comparisons →

Four models, 1000–3000 VA

The 2U models (1500 / 2000 / 3000 VA) deliver unity power factor (full watts = VA) with output selectable 200 / 208 / 220 / 230 / 240 VAC (capacity derates to 90% at 208 V); the compact 1U P91gc-1000 is 1000 VA / 800 W at 230 VAC. Optional locking-outlet dongles (L6-30R, L6-20R, 6-20, 6-15) are available. Rack depth is measured front bracket to unit panel; add 1 in for the front bezel.

Scalable runtime with external battery packs

Internal hot-swap batteries provide short ride-through; matching external packs scale runtime substantially. Each model shows runtime in minutes at 100% and 50% load, from internal-only out to eight packs.

Estimated minutes; values vary with battery age, temperature, and load profile. A maximum of eight matching packs is supported per 2U model (the high-capacity BP36E pack up to six). The P91gc-1000 uses internal batteries only. Size it with the UPS selector →

Built for distributed global infrastructure

The P91g is deployed across distributed infrastructure where continuous conditioning and runtime flexibility are required — AV systems, retail and hospitality, education facilities, and network closets — and is well suited to multi-site deployments standardizing a consistent UPS platform across locations with different runtime requirements.

Capacity guidance: 1500 VA for small AV and edge systems; 2000 VA for network infrastructure and distributed IT; 3000 VA for higher-density switching and edge compute. Runtime is defined by outage duration and shutdown strategy.

P91g specifications

Documents and related links