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Zenith DigiCommand PSG Paralleling Switchgear

Zenith DigiCommand PSG paralleling switchgear is a leading solution to simple and very complex systems due to its design flexibility and reliability.

ABB has been providing customer facilities with reliable power switching systems for decades. Since the inception of paralleling switchgear, hundreds of installations have been supplied with a focus on providing reliability.

Zenith DigiCommand PSG is a system design that has evolved and adapted to the changing technologies in engine generator design, switchgear controls and monitoring systems. It reflects ABB's continuing commitment to reliable solutions for critical power applications.

Mission critical facilities may be best served by paralleling two or more generator sets. Paralleling switchgear will monitor the status of the incoming utility and automatically start the generators if the utility is experiencing power fluctuations or an outage. Under parallel operation, any available generator may be used to support the load. In the event of a generator failure, the paralleling switchgear can redirect available generator capacity to the load designated with the highest priority, preventing a generator failure interrupting power to the most critical loads.

Paralleling power sources allow a facility a wide variety of choices in the generation, distribution and utilization of the system's power.

Uninterruptible Maintenance
When one engine - generator set is out of service for maintenance or repair, having others synchronized on the same bus can provide the needed back-up power, should an outage occur.

Cost Savings
Savings can be realized on the application when a number of smaller sets would be less expensive than one large set or when the load makes it impractical to divide into several sections, each with its own generator. Savings can also occur on the operation side when generator set life is extended from being used only when needed to support the load. Also, when it is anticipated that the load will grow significantly in the future, the capital investment can be reduced by starting with small sets and paralleling additional units as load increases dictate.

Features & Benefits

The Zenith DigiCommand PSG provides the following standard functions:

  • Controls for up to 16 generators and two separate buses
  • Controls different types of generators such as MTU, Cummins and CAT
  • 18” Advanced Control System touch screen. With multiple screens as described below 
  • Manage up to 16 loads
  • Single utility single generator main breakers control
  • Open transition mode of operation between utility and generators
  • Modbus communication to the engine generator sets
  • Modbus communication to up to:
    - 16 ABB breakers [Entelliguard trip units] distributing the load
    -  or up to 32 ABB ATSs 
  • Modbus TCP to Building Management System [BMS] or Power Monitoring and Control System [PMCS]
  • Electrical metering for the generators
  • Alarm and Event logging
  • Different non-emergency system tests:
    - Test no load
    - Test with load
    - Test with load bank
  •  Intuitive interface makes operation simple. Little or no learning curve required to operate system.
  • A main screen with navigation buttons and non-system critical button/switches.
  • System testing screen allowing the operator to manually initiate automatic system testing operations.
  • Generator interface settings latched into the PLC control system upon entry.
  • Generator optimization settings latched into PLC control system upon entry.
  • The system is designed to dynamically add or shed load based on the system load level rather than using inflexible load blocks.
  • The system is programmed to dynamically track the size of each load individually. This allows the system to quickly determine exactly how many loads are to be added to or shed from the system, whether it is in the middle of the afternoon or in the middle of the night.
  • A generator controller is added, if required, which has the functionality required by different applications and the flexibility to communicate with all types of existing engines. 


  • UL508 Listed Controls
  • Available for controlling both Low Voltage and Medium Voltage
  • NEMA 1 and NEMA 3R enclosures
  • Seismic Certified