GuardII+ – Generator and Motor Condition Based Monitoring

Continuous Online Monitoring of Flux, Partial Discharge, End Winding Vibration and Shaft Current on Generators and Motors

Product Overview

The Iris Power GuardII+ is one of the most versatile and reliable condition based monitoring instrument available. It is capable of collecting data, analyzing results and communicating with third party networks about the condition of generators and motors, including continuous online monitoring of Partial Discharges, Rotor Magnetic Flux for Shorted Turn Detection, Stator End-Winding Vibration and Shaft Voltages or Current.

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Partial Discharge Monitoring:

Collection of partial discharge pulse data through 80pF Iris Power Epoxy Mica Capacitors (EMC) or Stator Slot Couplers (SSC) and automatically analyzes the data using the diagnostic software to provide the information needed to understand the severity and location of insulation abrasion, loose stator wedges, thermal degradation of stator insulation and manufacturing defects of stator bars.

Rotor Magnetic Flux Monitoring

Collection and analysis of flux data from any flux probe in real time, providing the user with data on rotor winding shorted turns without adjusting the load settings. The magnetic field of the rotor is analyzed in real time to identify anomalies in the flux due to shorted rotor turns. This can also identify changes in the air-gap between the rotor and stator, key or stator migration and out-of-round or off-center rotors.

End winding Vibration Monitoring

Simultaneous monitoring of up to 25 channels from Iris Power EVAII fiber optic accelerometers to provide detailed analysis of acceleration, velocity, and displacement for each channel.  Automated alerts and alarm outputs based on displacement levels in order to provide a means of avoiding considerable collateral damage resulting from phase‐to‐phase faults or broken copper conductors.

Shaft Voltage and Current Monitoring

Shaft monitoring to indicate the presence of high levels of voltage or current on the motor or generator shaft in order to detect poor grounding shaft performance prior to bearing failures.

Product Details


Partial Discharge

  • Ideally used with permanently installed Iris Power 80pF Epoxy Mica Capacitors (EMC)
  • Remote inputs with 8 analog points proportional to operating conditions such as equipment temperature, voltage, current or power. These conditions are recorded for trending and analysis.
  • The GuardII+ uses superior automatic noise separation technology based on filtering and pulse shape analysis to reliably distinguish partial discharges from electrical interference (noise) to prevent false alarms.
  • In response to a partial discharge alert, users can review the pulse height analysis plots, and the 36-window phase resolved PD plots using basic interpretation to confirm the cause of the alert

Rotor Magnetic Flux

  • Ideally used with permanently installed Iris Power Total Flux Probe (TFProbe) or Folding Flux Probe (FFProbe)
  • Inputs for shaft sync sensor (Keyphasor) to determine which poles have shorts detected.
  • The diagnostic software provides instant analysis to indicate the presence and location any rotor poles with shorted turns by
  • High speed acquisition capability creates a table of results covering each pole and each load point

End-Winding Vibration

  • The hardware and diagnostic software allow for various configurations of single-axis and dual-axis accelerometer packages to suit the need of any application.
  • Optional 4-20mA output modules can be included with the package that typically uses USB, Ethernet or Modbus.

Shaft Voltage and Current Monitoring

  • Continuously monitors up to 4 inputs including 2 voltage and 2 current
  • Accepts currents from existing grounding brushes using two different shunt values
  • Automatic analysis and output of alerts on high level of current and voltage


  • The GuardII+ can operate “stand alone” system with only periodic downloading of archived data or it can be networked into the plant control system for remote data acquisition and analysis through USB, Ethernet or Modbus.
  • All alerts generated by the GuardII+ instrument may also be connected to a plant monitoring system.
  • Combined with the Iris Application Manager (IAM),  data can be collected from GuardII+ units on multiple rotating machines which can be monitored continuously at a  given time.


Options for data acquisition from:

  • GuardII+ units appropriately configured for either Tubo Generators, Hydro Generators, or High Voltage Motors
  • Sensor packages, commissioning, and training are also offered with the GuardII+ instrument

Get a Quote

Call us at +1 905.677.4824 or Toll Free at +1 888-873-4747 or fill out our online quote form below.

Learning Center

This Resource Library is designed to provide current, relevant resources that provide technical knowledge and practical solutions for owners and operators of rotating machines. We encourage you to use the search feature and filters to locate specific resources of interest.


Articles, Technical Papers, & Case Studies

Stator End-Winding Vibration in Two-Pole Machines – Avoiding Generator Failure

IN THE PAST 15 YEARS, INSURANCE INDUSTRY DATA HAVE indicated that stator end-winding vibration has become the most important ...



Hands-on, practical experience

EL CID Training | Electromagnetic Core Imperfection Detection – October 1-3, 2024 – Iris Power, Toronto, Canada

Reasons to Take The Course Mechanical, electrical and environmental stresses can cause a breakdown in the inter-laminar insulation on Stator Core…


IRMC 2024 June 17-20, 2024 - Renaissance Las Vegas, Las Vegas NV

IRMC 2024

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