True ripple-free DC current up to 600 A weighing only 7-8 kg
RMO-A
Microhmmeters
RMO-A
Micro-ohmmeter for circuit breakers
Contact resistance measurement in manufacturing, commissioning and maintenance.
Up to 600 A without ripple
The series generates a true DC current, with less than 1% ripple, in an automatically regulated ramp that rises before measuring and falls afterwards: magnetic transients are removed and the measurement reaches a typical accuracy of ±(0.1% of reading + 0.1% of full scale), using Kelvin's four-point principle.
Six models, three test modes
From the 100 A model to the 600 A one, all offer the SINGLE, CONTIN and DTRtest modes; the latter saturates the current transformers of dead-tank circuit breakers before the measurement.
Main features
- Range from 0.1 µΩ to 999.9 mΩ, expandable up to 6 Ω.
- Best resolution of 0.1 µΩ.
- 100 A test current continuously, without rest time.
- Optional high-precision module: 1 to 30 µΩ with 0.01 µΩ.
- Internal memory for 500 timeand date-stamped measurements.
- Optional thermal printer and Bluetooth.
- Cancellation of electrostatic and electromagnetic interference.
Applications and software
Applications
- Contact resistance of mediumand high-voltage circuit breakers.
- Live-tank and dead-tank breakers (DTRtest mode).
- Disconnectors, busbar joints, cable splices and welded joints.
- Fuses and other high-current links in factory or substation.
- Pass/fail criterion with Rmax limit on the device and on the PC.
PC software for control and analysis
The included PC software controls the test over USB or RS232, records results at configurable intervals in continuous mode, downloads the memory with search filters and generates configurable reports with export to Excel.
High output power
The high output voltage widens the measuring range at high currents and allows longer or thinner cables: the 600 A model measures up to 5.3 mΩ with 5 m / 50 mm² cables, and the 100 A model accepts 20 m cables of only 16 mm².
| RMO-A�—�MEASUREMENT�DATA | |
|---|---|
| Resistance range | 0.1 µΩ – 999.9 mΩ; expandable from 0 to 6 Ω |
| Resolution | 0.1 µΩ (up to 999.9 µΩ); 1 µΩ (up to 9.999 mΩ); 10 µΩ (up to 99.99 mΩ); 0.1 mΩ (up to 999.9 mΩ) |
| Typical accuracy | ±(0.1% of reading + 0.1% of full scale) |
| Test current | Selectable, up to 600 A DC depending on model; ripple < 1% |
| Open-circuit voltage | 10 V DC ±2% |
| High-precision module (optional) | 1 to 30 µΩ with 0.01 µΩ resolution |
| Memory | 500 time- and date-stamped measurements |
| Test ramp | Automatically regulated, progressive rise and fall |
Specifications valid at +25 °C with the recommended accessories.
The manufacturer reserves the right to change the specifications without prior notice.
RMO-A�—�TECHNICAL�SPECIFICATIONS
| RMO100A | RMO200A | RMO300A | RMO400A | RMO500A | RMO600A | |
|---|---|---|---|---|---|---|
| Maximum current | 100 A | 200 A | 300 A | 400 A | 500 A | 600 A |
| Duration at maximum current | Continuous | 150 s | 150 s | 50 s | 30 s | 20 s |
| Consumption at 230 V AC | 1210 VA | 1890 VA | 2360 VA | 3520 VA | 3930 VA | 4560 VA |
| Full-load voltage (230 V) | 7.30 V | 7.20 V | 6.10 V | 6.70 V | 6.00 V | 5.80 V |
| Weight | 7 kg | 7 kg | 7.5 kg | 7.5 kg | 8 kg | 8 kg |
Common to all models: dimensions 198 × 255 × 380 mm; supply 90 – 264 V AC, 50/60 Hz; backlit 4 × 20 character LCD; USB (optional RS232 and Bluetooth); IP50; operating temperature -20 to +55 °C; storage -40 to +70 °C; humidity 5 – 95% non-condensing.
Standards: IEEE C37.09 and IEC 62271-100 (circuit breaker testing); safety IEC EN 61010-1; EMC EN 61326-1. Specifications valid at +25 °C.
| C/ María Barbeito, 14 | Contact Contact +T [+34] 982 20 99 20 |
|---|---|
| 27003, Lugo, Spain | +T [+34] 982 20 99 20 info@amperis.com | www.amperis.com |