Transformerless 400 V series
Transformer 200 V series

Uninterruptible power supply (UPS)Uninterruptible power supply (UPS series)

Power supply with high efficiency, high quality, and high reliability protects important loads from power failure.

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Product Features

Overall efficiency of the transformerless 400 V series
Overall efficiency of the transformer 200 V series
Output voltage transient variation characteristic (transformer 200 V series). IEC62040, AC output voltage transient variation characteristics.

We have been producing and conducting sales of uninterruptible power supply (UPS) from 1961 to today, and it has been used by customers in various industries.
We have two types of lineups, the 400V input/output series and the 200V input/output series, for the three-phase output UPS, and both of them have implemented high efficiency, space saving, and longer operational life of the main periodical replacement parts.

  • Reduction of electricity cost through high efficiency (97% or more with the 400 V series, 92% or more with the 200 V series)
  • Reduction of operating cost with longer operational life of the periodical replacement parts
  • Effective utilization of customer's space in a space saving
  • Output voltage transient variation characteristics (IEC62040-class 1 compliance) of the industry's highest class
  • 24-hour 365-day security support system with a remote monitoring function (optional)

Applications and Solutions

Our UPS is used in the important load facilities of various customers including financial services, broadcasting, government offices (prefectural office buildings and city halls), public facilities, data centers, and general buildings.

Meidensha Corporation provides the optimal UPS system meeting customer's needs.

Single machine system

  • A system configured with one UPS
  • During UPS inspection, power supply is continued to the load by the maintenance bypass circuit.

Parallel / individual switching system

  • Parallel system is configured by connecting multiple UPS which have built-in bypass switching circuit in parallel and has no common switching circuit.
  • Even if several UPS were failed, only the failed machines would be removed from the parallel connection, and the system can be continue powered by those working machines.
  • During inspection, the UPS can be continue powered by parallel release / parallel input of UPS one by one.

Common spare system

  • This system configures multiple UPS for each targeted load and backs them up with buckup UPS
  • The UPS power supply is carried out from the common machines during failure of the regular machines.



  200 V series
(transformer system)
400 V series
(transformerless system)
Equipment method Regular inverter power supply system
Rated capacity 20-300kVA 500kVA
Compensation time (standard) 5 min, 10 min
Overall efficiency 92% or more 97% or more
AC input Rated voltage
(allowable fluctuation range)
200,210.220V 415、420V
Source resultant pulse number Three-phase three-wire
(allowable fluctuation range)
50 Hz or 60 Hz
AC output Rated voltage 200,210.220V 415、420V
Voltage accuracy ±1%
Source resultant pulse number Three-phase three-wire
Rated power factor Delay 0.9 Delay 0.9 (option 1.0)
Type of rating 100% consecutive
125% 10 min
150% 1 min

100% consecutive
125% 10 min
150% 1 min
200% 2 sec

Voltage transient variation
 Rapid change of input voltage (±10%)
 At power failure and recovery of commercial power source
 Rapid change of load (0⇔100%)
 Output switching (bypass⇔UPS)
 At parallel connection and removal (same setting time as above)
±2% ±1%
±2% ±1%
±5% ±3%
±5% ±5%
±5% ±5%
30 ms or less 20 ms or less
Accuracy of frequency ±0.01% (at internal oscillation)
Distortion factor of voltage waveform 2.0% (at linear load)
5.0% (at rectifier load)
Energy storage device Lead storage battery
Cooling system Reinforced air cooling
Ambient temperature / relative humidity 0-40°C/15-90%

High efficiency & High performance

High efficiency

UPS transformer 200 V series
Overall efficiency of 92% or more has been achieved in a range from 20 kVA to 300 kVA. The highest level of a transformer system (built-in inverter transformer) in the industry. In particular, efficiency of 92.5% has been achieved for the 300 kVA machine.
UPS transformer 400V series
The 97%, which is the highest level of overall efficiency of the 400 V series transformerless type in the industry, has been achieved by using a three-level method for the PWM conversion circuit.

High performance

With its performance that can satisfy the output transient voltage characteristics required in JEC2433-2003 Class 1 during 100% load rapid change, it allows us to provide a stable power source to customers.

Space saving

Board dimensions of the UPS transformer 200 V series
The dimensions are reduced by 40% compared to the conventional board. (300 kVA machine)
Board dimensions of the UPS transformerless 400V series
The dimensions are reduced by 33% compared to the conventional board.

Maintenance and service

The times of replacement of the main maintenance parts were reduced for 15 years of the operational life that is expected for the equipment.

  • Cooling fan 8 years
  • Control power source 15 years
  • Electrolytic capacitor 15 years

We provide a security system by remote monitoring (*1), 24-hour Meiden customer center, and maintenance contract (*1).
The functions that can be provided by the information communication terminal are as follows.

  • Monitoring function (measurement, failure condition, machine condition)
  • Recording function (document, logger, system history)
  • Mail notification function
  • Data storage and downloading function
Inquiries about this product
[Electric Power Utility & Energy System Sales Division]