MJOLNER 200 A MICRO-OHMMETER WITH DUALGROUND SAFETY
With MJÖLNER 200 it is possible to make measurements according to the DualGround™ method. This means that the test object will be grounded on both sides throughout the test giving a safer, faster and easier workflow.
- Specifically designed for measuring contact resistances in circuit breakers, disconnecting switches, bus-bar joints, and other such devices
- Safer testing using the patented DualGround™ technology to test circuit breakers with both sides grounded
- Fully automatic testing- microprocessor-controlled
- Wide measuring range and test currents
- High-Power and lightweight
The MJÖLNER Series is designed to measure the resistance of circuit breaker contacts, bus-bar joints, contact elements in bus-bars, and other high-current links. This product has been designed with safety, ease of use, and versatility in mind.
It can be used anywhere to measure a low resistance value with high accuracy. It conducts true DC ripple-free current testing of bus bars, circuit breakers, fuses, etc.
It can be used anywhere to measure a low resistance value with high accuracy. It conducts true DC ripple-free current testing of bus bars, circuit breakers, fuses, etc.
Features and Benefits :
1. Grounding terminal
2. Connection for mains voltage
3. Switch for mains voltage
4. TEMP SENSOR
This interface is for the connection of a temperature probe for temperature compensation.
5. interface
for communication with PC and MJÖLNER Win.
6. DATALOGGER
Port to connect a USB stick for data logging. Results can be viewed with Excel.
7. REMOTE
Remote control connector The remote controls current value, start /stop of measurement and print out function.
8. Printer
9. Keys to control the menu functions
10. Start/Stop key with status LED
11. Adjustment keys to set the measuring current and all menu values
12. DC- current output
13. Sensing terminals
14. DC+ current output
15. Shunt output
16. Clamp sense input
MJÖLNER 200 test system is designed to serve a number of applications. The most common are contact resistance measurements of low-, medium- and high-voltage breakers and also at bus-bar joints, and other high-current links. The contact resistance measurements concerning breaker testing are particularly called for in the following standards: IEEE C37.09-1999 and IEC 62271-1 (2011). If the contact resistance is too high this will lead to power loss and temperature rise, which often leads to serious trouble. To avoid such problems, it is necessary to check the resistance at regular intervals. The following table demonstrates how important low resistance is at high currents:
| Current | Contact Resistance | Power Loss |
| 10 kA | 1 mΩ | 100 kW |
| 10 kA | 0.1 mΩ | 10 kW |
| 1 kA | 1 mΩ | 1 kW |
| 1 kA | 0.1 mΩ | 100 W |
At 10 kA a contact with the resistance 0.1 mΩ gives a power loss of 10 kW. This power loss in one single point will definitely confer a temperature rise, which may result in overheating and possibly premature failure.
APPLICATION EXAMPLES
Circuit Breaker testing
- Test of circuit breaker contacts
- Test of the connections to the breaker
Testing of Bus-bar
- Test of Bus-bar joints
- Test of connections
Everywhere you need to test a
low resistance/high current connection
- Switches
- Disconnecting devices
- Safety ground connections
- Welding points
- Fuses
- Cables