How do the real-power output and efficiency specs differ between the E3SUPS15KFBS and the SURT15KRMXLT-1TF10K?

Both units are rated at 15,000 VA, but their watt ratings diverge significantly. The E3SUPS15KFBS is rated at 15 kW with a 0.9 power factor (leading and lagging), while the SURT15KRMXLT-1TF10K is rated at 12,000 W maximum configurable — a 20% reduction in real-power capacity at the same VA rating, implying an effective power factor ceiling of 0.8.

Efficiency compounds this gap. The SURT15KRMXLT-1TF10K specifies 93% efficiency at full load. The E3SUPS15KFBS does not provide a comparable percentage figure in the supplied specs — only a voltage range entry is listed under that field (304–477 V), which appears to be a data entry error rather than an efficiency rating. Buyers requiring a verified full-load efficiency number for energy cost modeling cannot confirm one for the E3SUPS15KFBS from the provided data.

Output harmonic distortion also differs: the E3SUPS15KFBS specifies less than 3% THD on a linear load, while the SURT15KRMXLT-1TF10K specifies less than 5% harmonic distortion. For sensitive power-quality-critical loads, the E3SUPS15KFBS's lower distortion threshold is the stronger spec on paper.

What are the key physical, installation, and battery differences that affect deployment planning?

Form factor is the sharpest divide. The SURT15KRMXLT-1TF10K is rack-mounted at 16U and ships with 4 battery modules already installed, reporting a net weight of 347.73 kg (766.61 lb) and physical dimensions of 70.8 cm H × 43.2 cm W × 77.3 cm D. It is designed for standard 19-inch rack infrastructure. The E3SUPS15KFBS is a floor-standing tower (140 cm tall, 112 kg net weight without batteries) targeted at electrical room installation. It ships with zero battery modules and has 3 empty battery slots — external battery modules must be purchased and installed separately before the unit can provide runtime.

Runtime readiness out of the box therefore favors the SURT15KRMXLT-1TF10K, which includes 4 RBC units and specifies a 2.5-hour typical recharge time. Battery voltage also differs: the E3SUPS15KFBS operates at 240 V DC bus, while the SURT15KRMXLT-1TF10K uses a split ±192 V battery referenced to neutral. The SURT15KRMXLT-1TF10K further specifies battery life at 3–5 years; no equivalent figure is provided for the E3SUPS15KFBS.

The E3SUPS15KFBS supports three-phase 380/400/415 V input, appropriate for international electrical room distribution panels. The SURT15KRMXLT-1TF10K takes 208 V single-phase input (2PH + G hardwire) with the bundled step-down transformer enabling 120 V output — a fundamentally different input architecture suited to US data center row power.

How do connectivity, environmental ratings, and surge/noise protection compare for data center and IT applications?

Output connectivity is a critical differentiator for IT deployments. The SURT15KRMXLT-1TF10K provides a rich receptacle complement: 2× NEMA L5-20R, 4× NEMA L6-20R, 2× NEMA L6-30R, and 2× NEMA L14-30R, plus a 4-wire hardwire output — directly serving rack-mounted IT equipment at both 120 V and 208 V simultaneously. The E3SUPS15KFBS specifies no output receptacles in the provided data; it targets hardwired electrical room distribution rather than direct device connection.

Network management differs by generation. The SURT15KRMXLT-1TF10K ships with a pre-installed SmartSlot Network Management Card 2 (NMC2). The E3SUPS15KFBS supports an optional Network Management Card 3 (NMC3) but does not include one. NMC3 is the current-generation card with broader cloud and IPv6 support; NMC2 is an older platform. The SURT15KRMXLT-1TF10K also specifies full-time multi-pole noise filtering, IEEE surge let-through of 0.3%, and zero-clamping response time — none of these surge/filtering parameters are provided for the E3SUPS15KFBS.

Operating altitude favors the SURT15KRMXLT-1TF10K at 0–10,000 ft versus 0–3,333 ft (or up to 4,921 ft per the secondary spec entry) for the E3SUPS15KFBS — relevant for high-altitude deployments. Both units share IP20 protection, 0–95% non-condensing relative humidity tolerance, and a maximum operating temperature of 40°C (104°F). The SURT15KRMXLT-1TF10K specifies a warranty of 2 years repair or replace; no warranty term is listed in the E3SUPS15KFBS specs. Acoustic output favors the SURT15KRMXLT-1TF10K at 50 dBA versus 60 dBA for the E3SUPS15KFBS.

Which should you choose: the E3SUPS15KFBS or the SURT15KRMXLT-1TF10K?

Our take: The SURT15KRMXLT-1TF10K is the stronger choice when the deployment is a US-based IT data center or server room requiring rack-mount form factor, immediate battery-backed runtime, and direct receptacle outputs at both 120 V and 208 V. It ships with 4 battery modules already installed versus 0 for the E3SUPS15KFBS, delivers a specified 93% full-load efficiency (no comparable figure is available for the E3SUPS15KFBS), and operates at altitudes up to 10,000 ft versus approximately 3,333–4,921 ft. Its pre-installed NMC2 card and detailed surge specs (0.3% IEEE let-through, zero-clamping) add immediate remote manageability and power conditioning out of the box. Conversely, the E3SUPS15KFBS is the correct selection for three-phase electrical room infrastructure operating on 380/400/415 V international distribution panels, where its 15 kW real-power rating (versus 12 kW for the SURT) and lower THD specification (less than 3% versus less than 5%) are material advantages for non-IT critical loads.

Side-by-Side Comparison

Spec-for-spec, from manufacturer data.

Frequently Asked Questions

Related Resources

• APC by Schneider Electric E3SUPS15KFBS product page — full specs and to add to a quote
• APC by Schneider Electric SURT15KRMXLT-1TF10K product page — full specs and to add to a quote