Eaton 9355 UPS 10-30kVA

Eaton 9355 UPS

The Eaton 9355 UPS (formerly Powerware 9355 UPS) provides premium double-conversion backup power and scalable battery runtimes for IT and electrical engineering infrastructure in corporate, healthcare, banking and industrial applications. Packing maximum battery runtime into a very small footprint, the 9355 UPS is a complete three-phase power protection solution. The 9355 can be equipped with an integrated, customizable power distribution module that includes a maintenance bypass switch.

  • Power rating: 10, 15, 20 and 30 kVA at 0.9 power factor (three phase)
  • Form factor: Small-footprint tower, black
  • Topology: Double conversion
  • Battery backup: Up to 22 minutes typical, extendable up to three hours
  • Input voltage: 208V/120V or 220V/127V
  • Output voltage: 208V/120V or 220V/127V 480V: 120V/208V or 600V:120/208 with input isolation transformer (at 60 Hz only)Frequency: 50/60 Hz auto-sensing
  • Dimensions: 10 and 15 kVA two-high configuration: 32.2″ H x 12″ W x 32.5″ D 10 and 15 kVA three-high configuration: 47.8″ H x 12″ W x 32.5″ D 20 and 30 kVA: 66″ H x 20″ W x 34″ D

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Product description

Premium power protection

With the Eaton 9355 UPS, data center managers can safely eliminate the effects of electrical line disturbances and guard the integrity of their systems and equipment. The 9355 is
a true double-conversion, three-phase system that can be used to prevent loss of valuable electronic information and minimize equipment downtime.

  • The 9355 continually monitors incoming electrical power and removes the surges, spikes, sags, and other irregularities that are inherent in commercial utility power•
  • Working with a building’s electrical system, the 9355 supplies the clean, consistent power required by sensitive electronic equipment for reliable operatio
  • During brownouts, blackouts, and other power interruptions, internal batteries provide emergency power to safeguard operation


The 9355 constantly monitors its own operation such as voltage, temperature and function of internal components—and sends an alarm or takes action if it detects a potential problem.


If it senses a problem, the 9355 instantly transfers the power path to a bypass source with zero interruption in power. When the alarm condition passes, the 9355 automatically reverts from bypass to normal power. The 9355 UPS features a four-button graphical LCD that provides useful information such as load status, events,
measurements and settings.

Advanced battery management

The 9355 UPS offers innovative technologies to maximize the health and service life of its internal and external batteries:

  • ABM technology uses a unique three-stage charging technique that significantly extends battery service life and optimizes recharge time when compared to traditional trickle charging
  • Temperature-compensated charging monitors battery temperature and adjusts the charge rate accordingly, which properly charges the battery and greatly extends battery life
  • An integrated battery management system tests and monitors battery health and remaining lifetime, providing user notification to guide preventive maintenance

Eaton’s UPS batteries are field replaceable. One person, working alone, can easily replace a battery without disrupting data center operations or power to protected equipment.

Green power performance

The 9355 delivers a robust combination of low input current distortion and high power factor for maximum efficiency. Operating at greater than 90 percent efficiency across all load ranges, the 9355 helps to reduce utility costs, extend battery runtimes and produce cooler operating conditions. In addition, Eaton’s use of sustainable materials and highly efficient manufacturing technology results in dramatic savings in carbon footprint as compared to competitive UPS products.

Industry-leading scalability and redundancy

Today’s critical applications require redundancy for ultimate reliability—and the 9355 delivers. Eaton’s innovative Hot Sync technology and optional maintenance bypass parallel tie cabinet work together with the 9355 to provide an advanced, cost-effective UPS paralleling system.

The patented Hot Sync technology enables system load sharing, allowing any UPS module in the system to serve as a backup for any other module. Hot Sync’s wireless paralleling capability also ensures system stability in the event of a communications failure.

Using a wall-mounted maintenance bypass parallel tie cabinet, data center managers can easily parallel up to four 9355 UPSs for either redundancy or capacity. UPSs can
be quickly added to the pre-installed parallel tie cabinet and brought online in minutes, and individual UPSs can be isolated and swapped out for maintenance significantly
reducing installation and maintenance expenses.

Most other paralleling systems on the market use a top-down configuration in which the master fails when any subsidiary module fails. With Eaton’s unique approach, each UPS is independent, yet synchronized with the others to prevent any single point of failure and help eliminate costly downtime.

Additional paralleling benefits include:

  • Scalability, from 10 to 120 kVA using one parallel tie cabinet
  • N+3, N+2 or N+1 redundancy, from 10 to 90 kVA in a compact footprint—often in a smaller footprint than a single large UPS
  • Redundant battery systems, with each parallel UPScontaining its own internal batteries
Double Conversion Online UPS

Double Conversion Technology

Double Conversion Topology

The Eaton 9355  uninterruptible power supply uses the Double Conversion Online UPS topology.  This  provides the ultimate in clean and stable electrical power for critical applications.  Incoming AC power is fed to the UPS’ rectifier converting it from AC to DC power. The converted DC power routes to a battery charging circuit and to the inverter for conversion back to AC power. The resulting “double converted” electrical power is pure sine wave output providing near perfect electrical power for connected equipment.

To ensure 7/24 up time the double conversion UPS topology utilizes a static “bypass switch” within its circuity design. If the Eaton 9355 detects a system failure, audible alarms will sound as the bypass switch is engages. This routes power around the failed UPS and ensures critical load power to target equipment.  This very important feature allows for 100% up time for critical equipment during repair.

In the event of total power failure, the UPS will power off the rectifier when the loss of power is detected. The UPS’ internal backup batteries will continue to supply DC power to the inverter. There is no transfer time as the transition to battery power is instantaneous. This feature provides true uninterruptible power to mission critical equipment.

Technical Specifications


Eaton 9355

Rated Power Capacity (Apparent/Active)

9355 (10-15kVA)
9355 (20-30kVA)

Voltage/frequency range

50/60 Hz (45 to 65 Hz)
9355 (10 – 15 kVA): 208/120, 220/127 Vac
9355 (20 – 30 kVA): 208/120, 220/120 Vac

Efficiency (Maximum%)

91%, typical

Overload Capacity

150% for 5 sec / 125% for 1 min (online), 110% for 10 min

Max charging (adjustable)

9355 (10 – 15 kVA): Default is 3.4A per battery string. Charger current is configurable from 0.5A to 25A per string with an overall maximum of 34A (limited by input current)
9355 (20 – 30 kVA): Default is 8A

Battery Module

9 Ah, sealed, lead-acid, maintenance-free

Operating Temperature

50–104ºF (10–40ºC), 45ºC with 7.5% derating; Optimal battery performance: 77ºF (25ºC)

Operating Elevation

9355 (10 – 15 kVA): 9,843 ft. (3000m) without derating
9355 (20 – 30 kVA): <3000m

Acoustic Noise

9355 (10 – 15 kVA): <56 dBA at 1 meter (noiseless room) typical
9355 (20 – 30 kVA): <58 dBA at 1 meter depending on load


EMC COMPLIANCE 47 CFR Part 15/ICES-003 Class A
Quality ISO 9001:2015, ISO 14001:2004
SAFETY CERTIFICATIONS UL1778 5th Edition, CSA C22.2 No. 107.3-14, NOM-NYCE
SURGE ANSI C62.41 Category B3, IEC 61000-4-5


(1) RS-232, (1) relay contact, (1) REPO, (2) environmental input
COMMUNICATION SLOTS (2) X-Slot communication bays

Estimated Run-Time

Battery Run Time Chart: