Megger IDAX322 Insulation Diagnostic Analyser

Megger IDAX322 Overview

The Megger IDAX322 is an insulation diagnostic analyser that uses Dielectric Frequency Response (DFR), also known as Frequency Domain Spectroscopy (FDS). By measuring capacitance and loss (tan delta / power factor) over a range of frequencies, it assesses the condition of insulation in power transformers, bushings and instrument transformers — a laboratory-grade technique adapted by Megger for the field as part of the IDAX family.

Who the Megger IDAX322 is for

The Megger IDAX322 is built for utilities, transformer owners and test service companies who need to know how wet the solid insulation is without opening or draining the transformer, and who test many bushings and instrument transformers. Megger notes that moisture sits mainly in the cellulose, so an oil sample alone gives an unreliable picture, and that single-frequency tan delta can be misleading because of temperature effects.

Figures from Megger’s IDAX322 datasheet (V05a):

• Tan delta inaccuracy at 2 kV peak of 0.5% of reading + 0.01% absolute above 100 pF (+0.03% above 10 pF)
• Capacitance 10 pF to 100 µF, 0.5% + 1 pF; up to 1 kHz at 2 kV and 10 kHz on the 10 V range, with ITC referring tan delta to 20 °C
• Tolerates 10 mA of AC interference (1:10 SNR) and 20 µA DC
• Measures two test modes at once, such as UST-R and UST-B, and runs multi-mode sequences automatically
• Material models for RBP, OIP, RIP and RIS bushings; the DFR method appears in CIGRE TB 254, 414, 445 and 775 and IEEE C57.152 and C57.161

Browse related instruments in our power transformer testing and insulation testing ranges or on the Megger brand page. For a rugged unit with an on-board computer, see the Megger IDAX350; the compact Megger IDAX300 pairs with the Megger VAX020 amplifier for 2 kV work. For 12 kV line-frequency power factor tests, compare the Megger DELTA4000.

Megger IDAX322 Key Features

What sets the Megger IDAX322 apart for field DFR work:

• Built-in 2 kV peak, 50 mA source keeps readings on low-capacitance bushings and CTs well above the noise
• Dual ammeters for two simultaneous measurements, for example UST-R and UST-B in one run
• DFR (Dielectric Frequency Response / FDS) measurement of insulation condition
• Measures capacitance and tan delta / power factor across frequency
• Assesses moisture, oil conductivity and ageing in insulation
• Dedicated test procedures for power transformers, bushings and instrument transformers
• Temperature-corrected results for reliable comparison with reference data, using Individual Temperature Correction (ITC)
• Part of the proven Megger IDAX family of DFR analysers

Megger IDAX322 Applications

The IDAX322 is used to assess the moisture and ageing condition of transformer, bushing and instrument-transformer insulation. Its DFR analysis gives engineers a reliable, reference-based picture of insulation health, supporting maintenance decisions and life-extension of critical HV assets.

What comes with the Megger IDAX322

Included accessories for the IDAX322 (cat. no. AG-29090), per Megger’s datasheet:

• Megger IDAX322 insulation diagnostic analyser
• Measurement leads (18 m generator cable, red and blue 21 m measure leads with clamps) and a 5 m, 6 mm² ground cable
• Mains lead and software (IDAX for Windows on a 16 GB USB stick), plus USB cable and fixed interlock
• Soft backpack for the leads and the IDAX322 user guide

Megger IDAX322 in the IDAX family

The IDAX322 shares the DFR measurement capability of the IDAX range. The Megger IDAX300 works with an external PC, the IDAX300/S adds a second ammeter, and the IDAX350 adds a rugged waterproof case with an on-board computer. The IDAX322 is the model with the built-in 2 kV amplifier, which is why Megger recommends it for field testing of bushings.

Megger IDAX322 FAQ

Questions engineers ask before a DFR campaign:

• Does the transformer have to be opened or drained? No. The IDAX322 connects to the terminals and calculates moisture in the solid insulation from the frequency response.
• Why use 2 kV on bushings? Bushings and CTs have low capacitance, so the higher voltage gives a cleaner signal, and measuring up to 1 kHz helps diagnose these small test objects.
• Does it need a laptop? Yes. It runs from the IDAX Windows software on a PC connected by USB 2.0 or Ethernet.
• How heavy is the kit? The instrument is 13 kg and the lead backpack 10 kg; the unit measures 420 × 480 × 220 mm.

Why buy the Megger IDAX322 from MME in the UAE

MME (MOHAMMAD MAHDI Electronics Trading LLC) is an authorized Megger representative in the UAE. We can help utilities and transformer service teams choose between the IDAX322, IDAX300 and IDAX350 and the accessory kit for bushing taps. Contact us for a quotation.