Winding Resistance Ohmmeter QRM10P

The QRM-10P is designed to accurately measure the winding resistance of highly inductive power transformers. The unit’s dual resistance-reading input channels can measure two winding resistances simultaneously, and four-wire (Kelvin) connections provide high accuracy and require no lead compensation.

The QRM-10P provides stable resistance readings of very large transformers by utilizing a 36Vdc power supply capable of outputting up to 10 Amperes. The resistance reading of a 100MVA transformer can be achieved in 5 minutes or less. The unit’s power supply is cooled by heavy-duty fans designed for continuous operation. For greater flexibility in the field, the QRM-10P comes with a built-in 2.5-inch wide thermal printer used for printing test reports.

Main Features

• Built-in Safety Features

At the end of each test, the QRM-10P automatically dissipates the stored energy in the transformer. This discharge circuit will continue to work even if the supply voltage is lost. For added safety, the unit’s power supply is thermally protected from over-load damage.

• Internal Test Record Storage

The QRM-10P can store 63 test records (up to 48 readings per test record) in Flash EEPROM. Test records can be retrieved and printed on the built-in thermal printer or can be transferred to a PC via the RS-232C interface port. Windows® -based software is provided with each QRM-10P that can be used to retrieve test records from the QRM-10P and can also be used to export records in Microsoft® Excel format.

• User Interface

The QRM-10P features a back-lit LCD screen (20 characters by 4 lines) that is viewable in both bright sunlight and low-light levels. A rugged, alpha-numeric, membrane keypad is used to control the unit.

• Built-in Thermal Printer

The QRM-10P features a built-in 2.5” wide thermal printer that can be used to print test reports in the field.

QRM-10P Specifications

Type	Portable transformer winding resistance meter
Physical specifications	17”W x 12K”H x 10K”D, (42.6 cm x 32.0 cm x 27.0 cm); Weight: 27 lbs (12.2 kg)
Operating voltage	100 - 120 Vac or 200 - 240 Vac (factory pre-set), 50/60 Hz
Resistance reading range	1 micro-ohm- 2,000 ohms
Accuracy	1 - 19,999 micro-ohms: ±0.5% reading, ±1 count; 20 - 999 milli-ohms: ±1% reading, ±1 count; 1- 2,000 ohms: ±1.5% reading, ±1 count
Test current	Auto range, 10 Amperes max
Test voltage	36 Vdc max
Resistance channels	Two static resistance reading channels
Display	Back-lit LCD Screen (20 characters by 4 lines); viewable in bright sunlight and low-light levels
Printer	Built-in 2.5-inch wide thermal printer
Internal test record storage	Stores 63 test records of 48 readings each
Computer interface	RS-232C
Pc software	Windows®-based software is included with purchase price
Safety	Designed to meet IEC61010 (1995), UL61010A-1, CSA-C22.2 standards
Environment	Operating: -10°C to +50°C (+15°F to +122°F); Storage: -30°C to +70°C (-22°F to +158°F)
Humidity	90% RH @ 40°C (104°F) non-condensing
Altitude	2,000 m (6,562 ft) to full safety specifications
Cables	Three 50-foot test cables, ground cable, power cord and cable bag
Optional accessories	Transportation case
Warranty	1 year on parts and labor

NOTE: the above specifications are valid at nominal voltage and ambient temperature of +25°C (+77°F). Specifications are subject to change without notice