The Megger MWA300 and MWA330A three-phase ratio and winding resistance analysers are advanced transformer test systems that provide complete ratio, phase, and winding resistance measurements with only one three-phase lead set connection. What’s more, they offer portability, a reduced set-up time, and increased job safety.


Once connected, the MWA300 and MWA330A perform DC resistance measurements on all high- and low-side windings without reconnection. It has an eight-terminal/six-winding resistance measurement capability and doesn’t need any interconnected boxes, allowing you to test all phase windings without having to disconnect and reconnect leads.


The MWA300 and MWA330A save you even more time by using a single software platform: PowerDB. This means you only need one setup and one easy-to-use test form.


The MWA300 and MWA330A can be used to effectively test power transformers, distribution transformers, CTs and VTs, and motors and generators. The following tests/functions are easily performed with a single instrument and one three-phase lead set connection:

  • Three-phase turns ratio
  • Three-phase winding resistance
  • OLTC continuity (make-before-break)
  • Three-phase core demagnetisation
  • Magnetic balance/flux distribution
  • Excitation current
  • Polarity and phase angle deviation
  • Auto vector detection
  • Heat-run test

The MWA300 is externally controlled by PowerDB software running on an external PC. The MWA330A, on the other hand, comes equipped with its own built-in computer that can be operated via a 305 mm (12 in) colour touch screen display and can store up to 100 000 data sets.

Input Power

MWA3xx: 108 to 132 V, (207 to 253 V*), 58 - 62 Hz, 660 VA

MWA3XX-47: 207 to 253 V, (108 to 132 V*), 48 - 52 Hz, 660 VA

*Input fuse change required - 6.3A fuse for 120 V nominal and 4.0A fuse for 230 V nominal line input.


Internal Data Storage

MWA330A (built-in computer): up to 100,000 data sets


Communication/Control Software

MWA3xx: PowerDB Lite

MWA330A: Controlled via built-in industiral PC or external customer PC.

The MWA330A’s internal computer is designed to control a limited

number of Megger instruments including the DELTA4000 as well as

the Megger S1 and MIT Series DC insulation testers.


Resistance

Resistance ranges:

Current Range | Resistance Range | Resolution

10 A | 10 mΩ to 0.2 Ω | 0.000001 Ω

10 A | 0.2 Ω to 2 Ω | 0.0001 Ω

1 A | 100 mΩ to 2 Ω | 0.00001 Ω

1 A | 2 Ω to 20 Ω | 0.001 Ω

100mA | 1 mΩ to 20 Ω | 0.0001 Ω

100mA | 20 Ω to 200 Ω | 0.01 Ω

10 mA | 10 mΩ to 200 Ω | 0.001 Ω

10 mA | 200 Ω to 2000 Ω | 0.1 Ω

Accuracy: ±0.25% Range ±0.25% Rdg

Resolution: Up to 4 digits


Excitation Current Specifications

Range and Accuracy:

0 to 500 mA, 3 digit resolution, ±(2% of reading + 1 digit)


AC Specifications (Turns Ratio, Winding Balance)

Range and Turns Ratio Accuracy:

8 V AC:

±0.1% (0.8 to 2000)

±0.25% (2001 to 4000)

±0.35% (4001 to 8000)

40 V AC:

±0.1% (0.8 to 2000)

±0.15% (2001 to 4000)

±0.3% (4001 to 10,000)

±0.35% (10,001 to 25,000)

80 V AC:

±0.1% (0.8 to 2000)

±0.15% (2001 to 4000)

±0.25% (4001 to 10,000)

±0.30% (10,001 to 45,000)


Phase Specifications (Phase angle deviation, Phase-shift analysis, auto Vector detection)

Input voltages: 8, 40, and 80 V AC

Range and Accuracy: ±90 degrees, 2 decimal points for the degree display, or for the centi-radian display

Accuracy: ±3 minutes (from 0.8:1 – 2,000:1)


MWA300 and MWA330A datasheet


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