10000 Woodward Avenue
Woodridge, Illinois 60517
+1 773-869-1776
+1 (773) 869-1329
United States
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100kVA/kW transformer provides 480V (Delta) to 208V (Wye) step-down and isolation protection to a 3-phase UPS and its load.

  • Recommended for government, manufacturing, healthcare and corporate settings
  • Up to 97.7% efficiency with a quiet acoustic profile less than 65 dBA
  • Resettable protection relay/switch and red LED indicator warn against overheating
  • Rugged stainless steel housing with compact footprint comes ready for installation
  • Compatible with 80–100kVA/kW S3M-Series 3-phase UPS systems
  • 2-year limited warranty


Get Complete Step-Down and Isolation Protection and Prevent Power Disruption
S3MT-100K480V 100kVA/kW transformer offers line isolation and protection to the connected 3-phase UPS system and its load. It isolates the UPS and connected components from line surges and spikes caused by utility power disruptions that can damage equipment or corrupt data. The step-down input isolation transformer is ideal for 4-wire (3Ph+N+PE) IT loads in government, manufacturing, healthcare and corporate settings with a 480V electrical feed and 208/120V equipment.

Performs with High Efficiency up to 97.7%
Not only is the S3MT-100K480V very efficient, with up to 97.7 percent efficiency, but it is also very quiet with a noise profile less than 65 dBA. A built-in circuit breaker on the output side helps prevent dangerous power overloads. Three large ball-bearing cooling fans help prevent overheating. An overheat-sensing relay and switch combine with a red LED indicator to provide over-temperature warning and overheating protection.

Small Footprint for Quick Installation in a Compact Space
The compact footprint enables installation of the S3MT-100K480V with minimal space. The rugged stainless steel housing ships ready for immediate installation with a compatible 80–100kVA/kW S3M-Series 3-phase UPS system.

Package Includes

  • S3MT-100K480V 3-Phase 100kVA Input Isolation Transformer
  • Owner’s manual
TAA compliant RoHS compliant


UPC Code037332253187
Efficiency96.7% @ full load
Nominal Voltage / Frequency480V 3-PH / 60Hz
VA / Watt Capacity100000
Transformer TypeDry type, Input step-down isolation transformer
Input Phase3-Phase
Nominal Input Voltage(s) Supported480V 3-PH Delta
UPS Input Connection TypeHardwire
Output Capacity (VA)100000
Output Capacity (kVA)100
Nominal Output Voltage(s) Supported120/208V 3-PH Wye
Output ReceptaclesHardwire
Primary Form FactorTower
Cooling Method3 x BALL BEARING, 172x152mm (723 TOTAL CFM)
Form Factors SupportedTower
Shipping Dimensions (hwd / in.)55.10 x 27.60 x 37.80
Unit Dimensions (hwd / in.)47.200 x 23.600 x 33.500
Unit Weight (lbs.)1078
Online Mode Heat Dissipation (BTU/Hr) @ Full Load  11263
Input Voltage480V 3-PH Delta
Input Voltage Range(-45%, +25%) for 40% load (-20%, +25%) for 100% load
Input Amp(s)168 A
AC Input ConfigurationDelta
AC Input Frequency50/60
Frequency Range40/70Hz
Voltage SelectionNONE
Input Inrush Current


VA Rating100K
Input Number of Phases3PH
AC Output Voltage (V)120/208V 3-PH Wye
AC Output Amps374 A
Output Number of Phases3PH + N
AC Output ConfigurationWYE
Output IsolationYes
Output Breaker Rating400 A
Connection TypeCOPPER BAR
LED Warning Light FunctionsThe over-temperature warning LED light will turn ON when the output/secondary of the Input transformer reaches 160°C ±5°C and will turn OFF wthen the corresponding transfomer cools down to 125°C ±5°C
Over Temperature Reset

If the secondary side of the input transformer reaches temperatures of or higher than 160°C ± 5°C, i.e. a range of 155°C to 165°C (311°F to 329°F), an over-temperature protection relay and thermal switch will activate and will open the breaker on secondary side of the transformer. Once the transformer temperature has cooled down to 125°C ± 5°C, i.e. a range of 120°C to 130°C ( 248°F to 266°F) the warning LED light will turn OFF, and you may manually re-activate (close) the output breaker on the transformer to restart normal operation..

Efficiency @ Half Load


Efficiency @ Full Load


Heat Dissipation (BTU/Hr) @ Full Load11263
Audible Noise (dBA @ 1m)65dB max
UPS ApplicationsMission Critical Applications
Efficiency @ Half Load


Efficiency @ Full Load


Product ComplianceTrade Agreements Act (TAA)
Product Warranty Period (U.S. & Canada)2-year limited warranty

Questions & Answers

Need help with your purchase?
We're always available to help with questions, including product selection, sizing, installation and product customization. Call us at +1 773-869-1776 or email