GuardII+ 4208 IPB – Partial Discharge Monitoring for Busduct and Isolated Phase Bus-Bar (IPB)

Continuous Online Partial Discharge Monitoring

Product Overview

The GuardII+ 4208 instrument is the leading on-line continuous partial discharge monitor used on isolated phase bus and busduct globally.

Works with the Following Assets
Assists with the Following Type of Monitoring

Iris Power uses the GuardII+ 4208 to collect voltage pulse data from 80pF Iris Power Epoxy Mica Capacitors and analyzes the data using PDView diagnostic software to provide information need to avoid catastrophic failures, extending the life your asset and reducing the risk of unplanned outages.

All data analysis results automatically output from PDView provide information need to understand the severity and location of:

The results are the most repeatable and reliable information available which can also be referenced against the Iris Power severity tables which consist of a statistical review of over 700,000 machine tests globally to provide a relative health index against similar machines.

Product Details



  • 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.

Data Analysis

  • The GuardII+ 4208 uses superior automatic noise separation technology based on time of flight, filtering and pulse shape analysis to reliably distinguishing partial discharges from electrical interference (noise) to prevent false alarms.
  • In response to a PD alert, users can review the pulse height analysis plots, and the 24-window phase resolved PD plots using basic interpretation to confirm the cause of the alert


  • The GuardII+ 4208 can operate “stand alone” system with only periodic downloading of archived partial discharge data or it can be networked into the plant control system for remote data acquisition and analysis through USB, Ethernet or Modbus.
  • An alert output using a dedicated relay can activate a remote indicator of high partial discharge alert conditions.  The alert output may also be connected to a plant monitoring system.

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

Looking for more Information

Sign up to receive our latest whitepapers, webinars, new product information, product updates and more.