Industrial-grade automatic voltage regulation featuring a non-full-power semiconductor design.

The MiniEVR continuously monitors output voltage and quickly switches transformer taps when voltage falls outside regulation range. The MiniEVR™ automatic voltage regulator continuously conditions power with no operator or programming required. In the event of a malfunction, the automatic bypass actuates to isolate power electronics and controls while maintaining power to the load.

Industrial-grade means our MiniEVR is compatible with all load types and load-power factors and provides a minimum 1,000% fault-clearing capability. Unlike computer-grade products, the MiniEVR is designed for frequent high-inrush current and low-power factor loads without the need to oversize the product or sacrifice reliability.

MiniEVR Features

  • Highest overload capacity available for compatibility with all load types
  • Highest fault-clearing capacity available for reliable operation of protective devices
  • 99% efficiency for all but the lowest end of the load range
  • Continuous load current – no load current interruption on tap switching
  • Quickly corrects under/over voltage, sags, and swells
  • Automatic failsafe electronic bypass eliminates load current interruption in the event of a malfunction
  • Zero moving parts and fan-free design for increased reliability and no scheduled maintenance
  • Surge suppression and input circuit breaker are standard
  • Natural convection cooling

MiniEVR installation is simple. The unit arrives completely assembled and requires no programming, testing, measuring, setting of switches, or internal wiring. It installs much like a dry-type transformer: simply place the unit and make the input and output wiring connections.

MiniEVR Pricing

SizeCredit or DebitPurchase Order

All prices subject to change without notice. Quantity discounts available, contact UST for details.

Size (kVA) - Single Phase5, 7.5, 10
(for larger sizes see UST SureVolt™)
Input / Output Voltages1Ø/60Hz: 120, 208, 240, 480
1Ø/50Hz: 110, 220, 380, 400
Non-standard voltages available upon request.

Regulation / Operating Characteristics
RegulationNominal input voltage +10%/-22%, Nominal output voltage ±3 (other options available)
Regulation VariationNone – regulation constant for 0 to 100% load and any load power factor
Overload/Inrush Capability1000% - 1 second, 500% - 5 seconds, 200% - 1 min. ; 1000% fault clearing
Minimum LoadNo limitations, compatible with all load types
Load / Power FactorNo minimum or part load or power factor limitations, compatible with all load types
Tap SwitchingNo load current interruption or waveform distortion on switching at any load or power factor
Zero Crossing SensitivityNone, tap switching not dependent on determining load current zero crossing
Harmonic DistortionNo distortion added at any load or load power factor
Response Time1 cycle typical, regardless of load or load power factor
Efficiency99% typical
Operating Frequency± 3% of nominal frequency

Protection / Bypass
Surge SuppressionIncluded, complies with ANSI/IEEE C62.41, UL 1449
Failsafe Electronic BypassAuto-actuation on high temperature, over-current, or component failure with no loss of load

TechnologyElectronically controlled tap-switching series transformer design
Switching SemiconductorsNon-full power semiconductors. Individual SCRs are not required to carry full unit current
ControlsNo controls or programming required, no user-adjustable controls
CoolingNatural convection, no cooling fans used
TransformerDry-type auto-transformer, copper wound
EnclosureNEMA-1, ANSI 61 grey, other enclosure types & colors available (consult factory for specific requirements)
MonitoringContacts for remote indication of unit and surge suppression status are included
Audible Sound LevelLess than 65 dB @ 1 meter

Environmental Requirements
Temperature - HumidityAmbient 32° to 104°F (0 to 40°C) – Relative humidity 0-95% non-condensing
Operating Altitude0 to 3,300 ft (1000m)