RM31E 3:1 Rack/Tower Online UPS 6–10 kVA
RM31E is a compact 3U rack/tower online double-conversion UPS for sites with three-phase mains input and single-phase critical loads. It supports 3:1 and 1:1 operation, with DSP control, output PF 1.0, 0 ms online transfer, wide input tolerance, external rack battery cabinets and parallel operation up to 4 units by configuration. Ideal for server racks, telecom cabinets, control rooms, edge IT and commercial buildings with three-phase distribution.
Engineered for 3:1 Rack/Tower Critical Power
Three-phase input / single-phase output online rack/tower UPS architecture for sites with 3-phase utility supply and protected single-phase IT, telecom or control loads in 19″ cabinets.
3-Phase In / 1-Phase Out
Accepts 380 / 400 / 415 Vac three-phase input and delivers 220 / 230 / 240 Vac protected single-phase output for server racks, telecom, security and IT loads supplied from a 3-phase building feed. Single-phase input / single-phase output operation is also supported by configuration.
3U Rack/Tower Form Factor
Compact 3U rack/tower convertible design for standard 19″ cabinets or tower installation. Suitable for server rooms, telecom racks, control rooms and high-density IT environments. Optional rack rail kit supports 700–760 mm cabinet depths.
Online Double-Conversion VFI
True online UPS topology with IGBT rectifier, IGBT inverter and DSP control provides pure sine wave output and 0 ms online transfer from AC to battery for sensitive single-phase critical loads.
PF 1.0 Output / Low Input THDi
Output PF 1.0 (kW = kVA) provides full usable kW capacity. Active input control delivers input PF ≥0.99 and input THDi ≤3%, helping reduce upstream electrical stress and improve compatibility with cables, breakers and generators.
Parallel up to 4 Units
Up to 4 RM31E units can be configured in parallel for capacity expansion or N+X redundancy, subject to model configuration and project design.
Runtime & Monitoring Options
External RC-series rack battery cabinets support extended backup runtime. Communication options include TM550 SNMP card and / or relay card for NMS / BMS integration, dry-contact signalling and remote monitoring by configuration.
Expand Your System
Accessories for RM31E runtime extension, remote monitoring, rack installation and maintenance bypass integration – available by configuration.
TM550 SNMP Card
Optional TM550 SNMP network card enables remote UPS monitoring, web access, event alerts and NMS / BMS integration. RM31E supports optional SNMP or relay card communication by configuration.
External Battery Cabinet
RC-series rack battery cabinets support long-runtime RM31E configurations. Battery string quantity and DC bus voltage are configured according to load level, target backup time and project design.
Rack Rail Kit
Adjustable 19″ rack rails for secure RM31E 3U installation in standard server cabinets, supporting 700–760 mm rack depth.
Maintenance Bypass PDU
External maintenance bypass PDU supports UPS isolation or replacement while maintaining load supply, when installed and operated according to procedure.
Technical Details
Complete specifications for the RM31E 6–10 kVA series.
| Specification | 6 kVA | 10 kVA |
|---|---|---|
| Full Name | RM31E Online Rack/Tower UPS | |
| Topology | Online double-conversion VFI, DSP-controlled (IGBT rectifier + IGBT inverter) | |
| Phase | 3:1 / 1:1 operation (3-phase in / 1-phase out; 1-phase in / 1-phase out supported by configuration) | |
| Form Factor | 3U rack / tower convertible | |
| Capacity | 6 kVA / 6 kW | 10 kVA / 10 kW |
| Output Power Factor | PF 1.0 standard | |
| Input Voltage | 380 / 400 / 415 Vac 3Ph+N+PE; 220 / 230 / 240 Vac 1Ph supported by configuration | |
| Display | LCD | |
| Operating Modes | Normal (Online), ECO, Bypass, Battery | |
| Parallel | Up to 4 units by configuration | |
| Standards | CE, IEC / EN 62040-1, IEC / EN 62477-1, IEC / EN 62040-2 (EMC), LVD (by series) | |
| Specification | 6 kVA | 10 kVA |
|---|---|---|
| Input Voltage | 380 / 400 / 415 Vac 3Ph+N+PE; 220 / 230 / 240 Vac 1Ph supported by configuration | |
| Input Range | 208–478 Vac (3-phase input); 120–270 Vac (1-phase input) | |
| Input Frequency | 40–70 Hz; 50 / 60 Hz auto-sensing | |
| Input Power Factor | ≥0.99 (active PFC) | |
| Input THDi | ≤3% | |
| Output Voltage | 220 / 230 / 240 Vac L+N+PE, ±1% | |
| Output Power Factor | PF 1.0 standard (kW = kVA) | |
| Output THDv | ≤2% linear load; ≤5% non-linear load | |
| Transfer Time | 0 ms (AC→Battery); 0 ms (Inverter→Bypass) | |
| Crest Factor | 3:1 | |
| Online Efficiency (VFI) | Up to 93% | Up to 93.5% |
| ECO Mode Efficiency | Up to 96% | Up to 97% |
| Specification | Details |
|---|---|
| Battery Type | 12 V VRLA lead-acid maintenance-free |
| Battery Configuration | 16 / 18 / 20 pcs configurable |
| Standard DC Bus | ±96 / ±108 / ±120 Vdc |
| Long-Run DC Bus | ±192 / ±204 / ±216 / ±228 / ±240 Vdc, 32–40 pcs supportable |
| Charger Current | 6 kVA: up to 12 A; 10 kVA: up to 14 A |
| External Battery Cabinets | RC20120N / RC40120N rack battery cabinets |
| Derating Note | 20 pcs: no output derating; 18 pcs: PF 0.9; 16 pcs: PF 0.8 |
| Battery Runtime | Sized according to load level, battery capacity and target backup time |
| Specification | 6 kVA | 10 kVA |
|---|---|---|
| UPS Dimensions (W×D×H) | 443 × 580 × 131 mm | |
| Rack Height | 3U | |
| Net Weight | 27 kg | 28 kg |
| Installation | Rack / tower convertible | |
| Rack Rails | Optional 19″ rack rail kit, 700–760 mm depth | |
| External Battery Cabinet | RC20120N: 3U; RC40120N: 4U | |
| Colour | Black | |
| Interface | Details |
|---|---|
| Standard Communication | RS-232, RS-485, EPO, output port, MAINTAIN-AUXSWS |
| Optional Network Card | TM550 SNMP card |
| Optional Relay Card | Relay / dry-contact card by configuration |
| Monitoring Integration | NMS / BMS / remote monitoring by configuration |
| Maintenance Bypass | Optional external maintenance bypass PDU |
| Display | LCD panel |
| Parallel | Parallel kit for up to 4 units by configuration |
AC Mode Overload
| Load Level | Duration | Action |
|---|---|---|
| ≤110% | 60 minutes | Sustained, then transfer to bypass |
| ≤125% | 10 minutes | Transfer to bypass |
| ≤150% | 1 minute | Transfer to bypass |
| >150% | Immediate | Transfer / protection per alarm table |
Battery Mode & Bypass
| Mode | Behaviour |
|---|---|
| Battery Mode | Shorter overload tolerance; refer to manual alarm / protection table |
| Bypass | Subject to bypass input and protection limits |
Protections & Alarms
| Protection | Description |
|---|---|
| Input | Over-voltage / under-voltage / over-frequency / under-frequency / phase loss |
| Output | Over-voltage / under-voltage / overload / short-circuit |
| Battery | Low-battery warning, over-discharge protection |
| Inverter | Over-temperature, fan failure detection |
| EPO | Emergency Power Off |
| Alarms | Buzzer + LCD + LED indicators (Line / Battery / ECO / Bypass / Battery Low / Overload / Fault) |
| Parameter | Specification |
|---|---|
| Operating Temperature | 0–40 °C |
| Storage Temperature | −25 to +55 °C |
| Relative Humidity | 0–95% non-condensing |
| Altitude | <1500 m without derating; derating required above 1500 m |
| Noise | <53 dB at 1 m |
| Protection Class | IP20 (indoor) |
| Cooling | Forced air (fan-cooled) |
| Safety | IEC / EN 62040-1, IEC / EN 62477-1 |
| EMC | IEC / EN 62040-2 |
| Certifications | CE, EMC, LVD (by series) |
Ideal For
RM31E is designed for 19″ rack or tower installations where three-phase utility or generator supply must feed protected 220 / 230 / 240 Vac single-phase critical loads at 6 or 10 kVA.
Server Rooms
3:1 rack UPS protection for server racks, switches, storage, firewalls and IT loads that require single-phase output from a three-phase building supply.
Telecom Cabinets
Compact 3U rack/tower UPS for telecom switching, routing, transmission and access equipment supplied from three-phase utility or generator power.
Edge Computing
6–10 kVA online UPS protection for distributed IT nodes and edge deployments requiring three-phase input with protected single-phase output.
Network Closets
Rack/tower UPS for switches, routers, firewalls and structured-network equipment in buildings with three-phase distribution and single-phase IT loads.
Security Systems
3:1 UPS backup for NVRs, access-control servers, alarm panels, monitoring workstations and security network racks powered from three-phase building distribution.
Financial IT
Online UPS protection for branch banking IT, payment systems, network racks, security servers and critical workstations supplied from three-phase distribution.
Need Single-Phase Input, PF 1.0 Rack or Full 3:3 Output?
If RM31E’s 3:1 rack/tower architecture is not the right match, compare related ATENCO online UPS series for standard single-phase input, PF 1.0 rack applications or full three-phase input/output loads.
RM31E 3:1 Rack UPS FAQ
Answers about RM31E three-phase input / single-phase output rack/tower architecture, 6–10 kVA capacity, PF 1.0 output, external battery runtime, parallel operation and monitoring options.
What does RM31E mean?
What is the difference between RM31E and TM31E?
What is the difference between RM31E and RM33E?
What capacities are available for RM31E?
Can RM31E be paralleled for redundancy?
What monitoring options does RM31E support?
What battery runtime options are available for RM31E?
Which applications is RM31E not recommended for?
Size Your RM31E 3:1 Rack UPS Project
Share your protected load list, target backup time, redundancy plan, 3-phase input voltage, rack details and monitoring requirements. ATENCO will recommend the suitable RM31E configuration – 6 or 10 kVA – with external battery cabinet, parallel and TM550 SNMP / relay options matched to your project.
Send Project Requirements
Share protected load in kW / kVA, target runtime, redundancy requirement, site 3-phase input voltage, rack depth and monitoring preferences such as TM550 SNMP, relay, BMS or NMS integration.
Receive UPS Selection & Sizing
ATENCO engineers recommend the suitable RM31E configuration: 6 or 10 kVA, battery cabinet selection, parallel plan, rack rail kit and matching TM550 SNMP or relay card accessories.