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Emergency Inverters

The IOTA IIS EXT Series Inverter is a UL Listed single-phase sine wave output inverter designed to provide power to designated emergency lighting fixtures in the event of a loss of normal power. In a power loss situation, the IOTA IIS EXT will supply 3.0KVA to 8.0KVA of emergency power from the battery supply at 2ms transfer time. The IOTA IIS EXT works in conjunction with any lighting load type and is capable of running normally-on or normally-off designated circuits in the emergency mode. The IIS EXT is ideal for providing emergency power to extensive 120V/277V lighting arrangements that utilize multiple lamp and fixture types. The IIS EXT conducts monthly and annual tests for operation readiness and logs the test results for reference as needed. The IIS EXT features a durable front-access NEMA 3R steel cabinet design suitable for outdoor use and is backed with a standard 1-year warranty.

Input Voltage

120/208/240/277VAC Single-Phase

Output Voltage

120/277VAC Single-Phase



Output Power

3.0kVA - 8.0kVA

Transfer Time

2 milliseconds

Emergency Operation

90 minutes

Load Power Factor Range

.5 lagging to .5 leading

THD (input/output)

<5% / <3%

Input Power Walk-in

Limiting inrush current to <125%,
10 times for 1 line cycle

Synchronizing Slew Rate

1Hz per second nominal

System Short Circuit


Static Voltage

+/- 2% (Load current change)
+/- 12.5% (Battery discharge)

Dynamic Voltage

+/- 2% (+/- 25% load step change)
+/- 3% (+/- 50% load step change)
recovery within 3 cycles

Inverter Overload Threshold

280% for 12 line cycles, 115% for 10 minutes

Crest Factor


Operating Temp

10° to 40° C

Storage Temp (electronics only)

-20° to 70° C

Relative Humidity

< 95%


Maintenance-free Valve Regulated Lead Acid (VRLA)

Audible Noise (standby mode)

45 dba @ 1m


UL 924 Listed
find the UL Mark on this product

*Input +/- 3%, Output in emergency +/- 0.05Hz

Advantages and Features

Product Advantages

  • Single-Phase emergency system with exceptional 97% power efficiency
  • NEMA 3R steel cabinet rated for outdoor installation applications
  • Fast 2 millisecond transfer time allows for uninterrupted operation of all lighting load types
  • Provides full light output in the emergency mode
  • Conducts required monthly and annual tests for operational readiness and logs test, event, and alarm data


  • PWM/IGBT inverter design for optimal switching speed
  • Micro-processor controlled, temperature compensating charger
  • Valve Regulated Lead Acid (VRLA) batteries provide long life and are maintenance free
  • Low Battery Voltage Disconnect protects batteries against deep discharge
  • Includes Input Circuit Breaker and Battery Fuse Protection
  • Output Circuit Breaker options available
  • User Programmable / Password Protected Interface
  • Touchpad interface and LCD display screen
  • Includes RS232 Serial Communications port
  • Locking NEMA 3R steel cabinet design with white finish
  • Temperature-controlled forced air cooling with no filter requirement
  • Meets or exceeds all National Electrical Code and Life Safety Code Emergency Lighting Requirements
  • Covered by IOTA’s standard 1-Year Warranty on all electronic components and pro-rated warranty on batteries
  • Factory Startup and Training available