Imaging the time you could save if your multifunction installation tester provided reliable non-trip loop testing at the first time of asking.
When you use an ordinary multifunction installation tester (MFT) to perform non-trip loop tests, it typically makes the measurement over a fixed time period of 15 seconds. That’s not long, but if the result isn't quite what you expected – possibly because of noise in the circuit under test – you may well decide to do a second test “just to be sure”, and maybe even a third! So now testing this circuit has taken a minimum of 45 seconds, but probably longer. And now there’s another issue: which of the three test results do you put on the certificate. It’s very unlikely they will be identical!
There has to be a faster and better way – and now there is!
A new MFT – the Megger MFT1741 – has just been launched that incorporates a unique “confidence function” for loop tests.
The principle is simple: when you carry out a non-trip loop test, your tester actually makes a large number of measurements before using these to calculate the result it shows on the display. The confidence function continuously monitors these measurements, and tells you when they become stable.
On a quiet circuit, which has low levels of electrical noise, this can take as little as eight seconds, which is a big time saving compared with 15 seconds or more with a conventional MFT. On a noisy circuit, the test may well take a little longer than 15 seconds, but there’s still a very important benefit – the result will be right first time.
You never need to perform multiple tests to make sure of getting a reliable result, and you never need to decide which of several different results should go on the test certificate. So, whether the circuits you’re working on are noisy or quiet, using an MFT with a loop test confidence function will save you valuable time, as well as making sure that you can complete the test certificate with a high level of confidence.