Rotabloc Integrated DRUPS System

Fully integrated system comprising the RBT UPS Module, Engine Genset, Switchgear, Control Systems, with Full Systems Integration.

IEM Power Systems can fully integrated UPS systems, delivering to your site a fully integrated and tested UPS solution. This unique approach saves you time, lowers cost, reduces risk and ultimately improves overall reliability.

IEM Power Systems' fully Integrated DRUPS systems comprises:
  • Rotabloc – UPS Energy Storage Unit 400 - 2000kVA (320 - 1600kW) (systems up to 50MW+)
  • Switchgear – Low and Medium voltage input and output switchgear
  • Engine Generator – The diesel gen-set can be located remotely and operated independent of the Rotary UPS
  • Control System – With a simple HMI this links the major UPS components and can be integrated into the facilities BMS
  • Rotabloc Control System Integration – Software integration that allows the elements of the system to perform as a single effective unit
With full integration and comprehensive system testing in the factory the benefits include:
  • No additional integration costs
  • Lower overall cost as the integration is undertaken as the system is built and it is not as an additional item
  • Increased reliability as the whole UPS system is designed and built to work together
  • The assurance that the system has been tested (including any MV sections) before it leaves the factory – minimizing time required for on-site testing, speeding up implementation, reducing project risk and promoting site safety

Only IEM Power Systems offer this fully integrated approach to DRUPS.

Power Rating 400 - 2000kVA (320 – 1600kW)
Frequency 50 or 60Hz
Voltage Range 400V / 480V
Load Power Factor Range 0.8 lag to 0.9 lead (adjustable)
Efficiency at nominal load 96% +
Ambient Temperature 0-40° (32-104° F), 113° F for Rotabloc
Altitude (without de-rating) ≤ 1000m (3280ft.)
Humidity ≤ 90%

The Diesel Engine Generator, UPS and Switchgear components are all controlled by a central operating system.

The system is both simple in its design and in its mode of operation. The Power Control System while operating the UPS, also manages the operation of the Diesel Engine Generator, ensuring that it:

  • Monitors the Utility supply for both voltage and frequency deviation
  • Comes up to speed at the required rate
  • Synchronizes with the Rotabloc
  • Manages load in a controlled manner
  • Resynchronizes automatically to a returning Utility supply
  • Reconnects to the Utility in a controlled fashion


The switchgear is also operated by the the control system guaranteeing that:

  • Breaker operation occurs in the correct sequence
  • Breaker sync check systems are UPS controlled



Normal Operation

In normal operation, the Rotabloc (RB) filters the supply to the ‘No-Break’ Loads and regulates the power factor at the utility service input.

Normal Operation

Total Utility Failure

When the Utility fails for more than 80ms, D1 opens. After 1 second the Engine Generator (EG) receives a ‘start’ signal.

From the start of the failure and through the EG start period the Rotabloc discharges into the ‘No-Break’ Load to maintain power. The ‘Short-Break’ Loads are disconnected (DE open) at this time.

As the generator comes up to speed, the Diesel syncs with the UPS and breaker DG closes (DM opens). All ‘No-Break’ Loads are maintained during this period.

Total Utility Failure

Diesel Gen-Set

After a short period of serving only the ‘No-Break’ loads, Breaker DE closes and reconnects the ‘Short-Break’ loads. The VFD then maintains the Flywheel speed or recharges it, dependent on EG rating. During this period all loads remain connected.

Diesel Gen-Set

Return of the Utility

When the Utility supply returns, the VFD, via the drive motor of the Rotabloc, ensures that the Flywheel is recharged. Once the Rotabloc is fully charged, the Utility breaker DM closes and the Generator Breaker DG is opened to disconnect the Genset which enters ‘cool down mode’. During this transfer all Critical Loads are maintained without a break.

Rotabloc UPS Advantages:
  • Efficiently protects the critical No-Break and Short-Break loads
  • Engine Generator can be operated and maintained independent of the Rotabloc UPS, supporting continuous running
  • Lowest maintenance requirements for any UPS solution
  • Flexible configurations for all applications up to 50MW+ in low and medium voltages and isolated parallel systems
  • Very low TCO, minimal maintenance costs, high efficiency with no a/c requirement
Rotabloc UPS Features:
  • Standard Alternator with no special windings and easy to adapt to your requirements
  • Low Speed Bearings with AutoLube extend system lifetime and reduce maintenance
  • Electromagnetic Coupling for no maintenance, frictionless energy transfer
  • Simple design using standard electrical and mechanical components lowers cost and increases reliability
  • Patented drive motor maintains the optional speed, automatically matching the needs of the No-Break load to the energy stored by the UPS system
  • Green technology – extremely recyclable, no a/c and very high operating efficiency – supports your facility’s green credentials

ESRF Rotary UPS Solutions