Are you sick of fluctuating measurements when you are loop testing? The latest innovation from Megger may just have the answer!
Non-trip loop testing is certainly convenient, especially in modern installations where almost every circuit is protected by an RCD or RCBO, but it’s not always completely straightforward. A particularly common issue is that the measurement fluctuates and if you repeat the test several times on the same circuit, every result is different. So how can you have confidence in your results?
Until recently, there was no easy answer, but now the first multifunction installation tester (MFT) to incorporate a novel “confidence” feature has been launched. It’s the Megger MFT1741 and, when it is used to carry out a loop test, it very quickly returns a provisional reading, but the display also shows an arc. The length of the arc diminishes as the test proceeds and, when only a single element is left, you can be highly confident of the result. A bonus is that, on quiet circuits, the high-confidence result is typically available within eight seconds.
But what about noisy circuits? For these, the tester operates in a very similar way, displaying a reading as the arc gradually shrinks. You can, if you wish, take the result while the instrument is in this “less confident” phase but, if you wait a little longer, the arc will diminish to the single element high-confidence state. If noise is detected while the arc is diminishing, it will expand again, indicating increased uncertainty, before it shrinks to a single element.
When you use this new confidence function, there really is no need to carry out repeated tests but if you do, you will find that they produce results that only vary by a small amount, if at all – provided, of course, that the readings have been allowed to settle to the high-confidence state.
The new MFTs with their innovative confidence function are nothing short of a revolution in loop testing. For the first time ever, they make it possible for you to perform non-trip loop testing easily and efficiently, and to be absolutely confident that the results are reliable.