Praxis PMS


The Mega-Guard Power Management System (PMS) is an advanced system for full automation of power plant, including power management, diesel engine control, generator control,  synchronizing, generator protection and optional diesel engine safety system.

Each generator set is equipped with its own independent and autonomous PMS system. This ensures the highest degree of reliability and availability. The Mega-Guard PMS is supplied as a complete product and no additional components are needed for automation of a low voltage switchboard up to 690VAC.

The Mega-Guard PMS is operated through a user friendly touchscreen (5,7″ or 8″) for intuitive operation and monitoring of power plant.

Reliable operation is  guaranteed by 6 operator pushbuttons for essential
functions. All essential power plant parameters are displayed on the touchscreen. The touchscreen supports swiping in between pages and activating sub menus with the touch of a finger.

Mega-Guard PMS is built-up with the following three items for each generator:

PMS Operator Panel for flush panel mounting in switchboard

PMS Controller for DIN rail mounting inside switchboard

I/O Cable interconnecting the PMS Operator Panel and the PMS Controller

Both the PMS Operator Panel and the PMS Controller are equipped with a powerful ARM microprocessor for independent function execution.


Mega-Guard PMS can be configured for a mixture of the following applications:

  • diesel generator
  • shaft generator
  • automatic bus tie breaker
  • emergency generator
  • shore connection

Mega-Guard PMS provides for auto starting, synchronisation and load sharing functions. Metering functions include 3 phase voltage, current, frequency and power measurement, calculation of power factor and running hours. Diesel engine,  enerator and circuit breaker are controlled and monitored by Mega-Guard PMS. Safety
functions are executed in accordance with the applicable ANSI standard (see PMS protection function table).

Other functions include black-out start, consumer enable when enough power and preferent tripping in case not enough power available.

Mega-Guard PMS includes a PLC programming option and graphic editor which is not needed for most switchboard applications. Special applications can be programmed with the built-in and optional PLC logic. The PLC logic is in accordance with the IEC61131 standard.

Mega-Guard PMS can be extended with additional modules to realize following functions:

  • Safety system for diesel engine
  • Differential tripping
  • Check synchronizer with back-up measurement of kW, V, A, Hz and Cos φ
  • Analog control for frequency and voltage
    Additional Controllers for user functionality (requires PLC programming option)
Installation and commissioning of Mega-Guard PMS can be executed by switchboard builder and does not require special skills. The technician can easily set switchboard and power plant parameters in the Mega-Guard PMS with the user friendly PMS Operator Panel with touchscreen. Parameters such as generator power, number of generators, bus tie breaker, busbar nominal voltage, alarm limits, type of generator etc. can easily be entered in the menu driven operator interface. 

PMS system lay-out

Mounting & dimensions