The Xtreme Power Conversion M90S-6S, configured for 18 kW usable output, and the Vertiv Liebert APS AS6C0NCWGNNXLKB are modular, true online, double-conversion UPS systems designed to protect mission-critical IT, network, and edge-infrastructure loads.
While both platforms support modular growth and hot-swappable components, the M90S-6S delivers full 18 kW output as a base configuration, longer baseline runtime, and integrated service features, whereas the Vertiv APS reaches 18 kW only when scaled to its maximum configuration.
18 kW Modular Online UPS Comparison
| Feature | XTREME POWER M90S-6S (18 kW) | Vertiv Liebert APS AS6C0NCWGNNXLKB | XPCC Advantage |
| Base Configuration Rating | 18 kVA / 18 kW (unity PF) | 15 kVA / 13.5 kW | Higher usable power out of the box |
| Maximum Scalable Rating | Scales to 24 kVA / 24 kW | Scales to 20 kVA / 18 kW (N+1) | Greater long-term growth headroom |
| Topology | Online Double Conversion | Online Double Conversion | Equivalent protection |
| Internal Runtime (Full Load, base battery) | ~9 min @ 18 kW | ~5 min @ full load | Longer baseline runtime without EBMs |
| Maintenance Bypass | Standard, integrated | External maintenance bypass option | Reduced accessories and installation cost |
| Display & Diagnostics | Chassis LCD + module-level displays | Removable chassis LCD | More granular local visibility |
| Certifications & Compliance | UL, cUL, TAA Compliant | UL, cUL | Clear positioning for regulated markets |
| Warranty Coverage | 3 years (electronics & batteries) | 2-year limited warranty | Longer standard coverage reduces lifecycle risk |
Printable Comparison PDF
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Where the M90S-6S (18 kW) Excels
- Deployments requiring full 18 kW usable output at base configuration
- Installations prioritizing longer runtime with base batteries
- Facilities planning future expansion beyond 20 kVA
- Projects seeking integrated maintenance bypass to simplify installation
- Regulated environments requiring TAA-compliant solutions
When Vertiv Liebert APS May Be a Fit
- Standardized Vertiv APS environments
- Deployments planning to scale up over time to reach 18 kW
- Architectures where external bypass cabinets are already planned
Who Should Choose Which
Choose Xtreme Power Conversion M90S-6S if you need:
- Full 18 kW usable output without incremental scaling
- Longer baseline runtime before adding EBMs
- Greater scalability headroom within the same platform
- Integrated service features to reduce installation complexity
- Longer standard warranty on electronics and batteries
Choose Vertiv Liebert APS if you need:
- Alignment with an existing Vertiv APS ecosystem
- A solution designed to scale up to 18 kW over time
- External bypass as part of a predefined architecture
Ideal Applications
- Edge and enterprise data-center deployments
- IDF/MDF closets with high power density
- Healthcare and laboratory environments
- Government and education infrastructure
- Modular UPS standardization projects
Plan with Confidence
Request a Quote
Speak with an Xtreme Power Conversion specialist to configure the right M90S-6S 18 kW modular architecture for your load, runtime, and compliance requirements.
Xtreme Power Conversion
Phone: (800) 582-4524
Email: sales@xpcc.com