Working on your own? Need some technical advice? Don’t know where to turn? The technical team at Megger answers the latest technical query from end users.
YOU ASK:
I’VE JUST LANDED A GREAT CONTRACT TO CARRY OUT REGULAR TESTING FOR AN INDUSTRIAL CLIENT. THE ONLY PROBLEM IS THAT THEY WANT PI MEASUREMENTS FOR ALL OF THEIR MOTORS. THESE TESTS TAKE AGES TO PERFORM AND THE CLIENT HAS A LOT OF MOTORS – IS THERE ANY WAY TO CUT DOWN THE TEST TIME?
MEGGER SAYS:
That’s a question a lot of our customers have asked. A polarisation index (PI) test normally takes a minimum of 10 minutes to perform. It has to be carried out separately for each phase, so it takes at least 30 minutes to test a three-phase motor. That’s too long, so we’ve developed PI Predictor (Polarisation Index Predictor), a new patent-pending technology. PI Predictor continuously monitors insulation resistance during the test and, after just three minutes, begins to compute an extrapolated value for PI and assess the stability of this value. When a stable PI result has been reached, the test stops automatically. In almost every case, this takes less than five minutes, although it may take a little longer if the asset’s insulation behaves atypically. In other words, the time needed to carry out a PI test on a three-phase motor is typically reduced from 30 minutes to 15 minutes or less, which is definitely a worthwhile timesaving. PI Predictor is currently available on insulation testers in the Megger S1 range, and is coming soon to the MIT range.
Get more details about Megger’s PI Predictor technology here
Read more ‘Made 2 Measure’ articles here
