Megger MJOLNER 200 Digital Microhmmeter

Megger MJOLNER 200 Micro-Ohmmeter

The Megger MJOLNER 200 is a 200 A micro-ohmmeter with DualGround safety, designed for electrical contractors, substation engineers, and industrial maintenance teams in Ireland who need accurate low-resistance measurements on switchgear contacts, busbar joints, and earthing connections in a more portable form than the higher-class MJOLNER 600. Powerpoint Engineering supplies the MJOLNER 200 alongside the wider Megger micro-ohmmeter range, with calibration, accessory supply, and operator training as part of our authorised Megger distributorship.

The MJOLNER 200 is the right tool when 600 A is more current than the test demands, and portability matters more than top-end capability. For typical distribution switchgear, MV breaker contacts, smaller busbars, and most earthing tests, the MJOLNER 200 has the test current to overcome contact film without the size, weight, and cost of a 600 A unit.

What the MJOLNER 200 measures

• Resistance of circuit breaker contacts: detect contact wear and erosion before it becomes a thermal problem.
• Busbar joints and bolted connections: verify joints are tight, clean, and within manufacturer specification.
• Earthing and bonding paths: confirm earthing connections and bonding straps are within their commissioning resistance.
• Cable terminations and lugs: contact resistance testing across the full range of bolted electrical connections.
• Welded and bolted contact elements: pinpoint loose or oxidised connections that show up as a higher resistance reading.

Using a 200 A DC test current is the difference between a real reading and a misleading one. At lower test currents, contact film and oxidation can give problems with incorrect test results due to low-energy probing of the actual contact surface. The MJOLNER 200 delivers enough current to push through that surface layer and measure the true bulk contact resistance.

DualGround safety on a 200 A platform

DualGround testing keeps both sides of the breaker earthed for the duration of the test. That removes the induced-voltage hazard that comes with a single-grounded approach and is now mandated by many utility safe-systems-of-work procedures. The MJOLNER 200 carries the same DualGround safety capability as the larger MJOLNER 600, designed with safety features at the top of the priority list, just at the smaller test-current rating that suits its target applications.

Specifications: what to confirm before you order

Target users and applications

• Electrical contractors carrying out planned preventative maintenance on industrial and distribution switchgear
• Substation engineers verifying contact resistance during commissioning and routine outages
• Industrial maintenance teams running condition-based maintenance on critical switchgear assets
• Renewable site operators testing interconnection switchgear, BESS connections, and earthing systems
• Service providers offering switchgear maintenance to multiple clients across Ireland

Typical applications include circuit breaker contact resistance measurement on distribution-class breakers, busbar joint verification on smaller switchgear, earthing path resistance verification, and acceptance testing of new switchgear at the distribution voltage classes. For larger transmission-class breakers and very low-resistance applications, the higher-current MJOLNER 600 is the right step up.

As authorised Megger distributor in Ireland, Powerpoint Engineering supplies the MJOLNER 200 with in-house calibration and repair, accessory supply, and operator training in DualGround micro-ohmmeter use.

FAQs

When should I choose the MJOLNER 200 over the MJOLNER 600?

For distribution-class switchgear, smaller busbars, and routine maintenance work, the MJOLNER 200 has enough test current to deliver accurate readings while being more portable and lower-cost than the MJOLNER 600. For transmission-class breakers, large generator switchgear, or applications where the contact path is very short and demands high test current, the MJOLNER 600 is the right tool.

Does the MJOLNER 200 support DualGround testing?

Yes. DualGround safety is built into the MJOLNER 200 micro-ohmmeter platform, allowing both-sides-grounded contact resistance testing on substations where the safe-system-of-work demands it. That is one of the main reasons it can be used anywhere a substation operator wants the safety margin of dual earthing without losing measurement accuracy.

Does the MJOLNER 200 need calibration?

Yes. As a precision test instrument, the MJOLNER 200 should be recalibrated periodically to remain trusted on contract and reporting work. Powerpoint Engineering's calibration laboratory recalibrates Megger micro-ohmmeters in-house and supplies a traceable certificate.

To match the right MJOLNER 200 configuration to your switchgear and test workflow, request a quote or speak to our team for compatibility advice.