Whether the MRW 1000 Limit, MRW 4-20mA or MRW CAN - all variants also have an insulated version. The insulated versions are always used in instances where live cables or lamps are used.
Additional manufacturing steps and special components ensure that no electrical current can damage the load cell.
The load cell meets the criteria of the DIN/VDE standard 0682-742 and is suitable for working on live parts up to AC 1000 Volt and DC 1500 Volt.
The manufacturing process is largely identical to that of a non-insulated MRW.
However, an additional insulation test is carried out after completion of the MRW.
MOBA plays it safe and tests every manufactured MRW 100% for its insulation properties.
For this purpose, the load cell is subjected to an insulation test. In this insulation test, one test pole is connected to the aluminium body of the MRW and the second test pole is connected to the wires of the connecting cable. The MRW is then charged with an increased test voltage of 3.5KV. The test voltage thus corresponds to more than triple the specified value in order to rule out any errors.
The test is passed if the MRW has not passed a voltage breakdown within a defined period of time.
The distinguishing feature of an insulated MRW design is the blue triangular sticker. A non-insulated version of the MRW is shown on the right for comparison.
To be able to carry out the test safely, MOBA uses an in-house developed insulation test stand. The test can only be started when the hood is closed, thus ensuring that no person can touch the load cell during the test. Due to the high voltage, touching the MRW could result in life-threatening injuries.