T
Thenitwentbang
I did originally post this in the Tools and Products area - but think that was probably the wrong place.
Recently, I purchased a Metrel MI3000. The initial impression was actually very good - looks robust enough and with very logical controls.
Shortly after getting it and whilst installing a SWA run to an outbuilding through a RCD spur, I had my first opportunity to test the No Trip PEFC facility. The readings were much higher than I expected (about 2 Ohms!!) so much re-checking of connections ensued, followed by another test - readings exactly the same. It's worth pointing out that the automated PSCC readings from the socket in the outbuilding were spot on.
My gut instinct is that the No Trip process is probably giving the unexpectedly high reading, so I took the meter into the house and tested from a socket adjacent to the spur (fed from the same ring). This seemed to confirm suspicion - no trip reading was almost exactly 1.5 Ohms higher than the standard (this socket is not RCD protected, so could perform both tests on it back to back). Reading with the No Trip facility set was 1.94 Ohms (so, that would be outside limits for the 32 A Type B breaker protecting the ring). However, with the No Trip facility switched off, the reading was a much more acceptable (and realistic) 0.43 Ohms.
So, long-wnded question, but can anyone throw some light on this for me? Until I've got it sorted, I'm definitely not going to trust the No Trip readings on this meter.
Cheers.
Recently, I purchased a Metrel MI3000. The initial impression was actually very good - looks robust enough and with very logical controls.
Shortly after getting it and whilst installing a SWA run to an outbuilding through a RCD spur, I had my first opportunity to test the No Trip PEFC facility. The readings were much higher than I expected (about 2 Ohms!!) so much re-checking of connections ensued, followed by another test - readings exactly the same. It's worth pointing out that the automated PSCC readings from the socket in the outbuilding were spot on.
My gut instinct is that the No Trip process is probably giving the unexpectedly high reading, so I took the meter into the house and tested from a socket adjacent to the spur (fed from the same ring). This seemed to confirm suspicion - no trip reading was almost exactly 1.5 Ohms higher than the standard (this socket is not RCD protected, so could perform both tests on it back to back). Reading with the No Trip facility set was 1.94 Ohms (so, that would be outside limits for the 32 A Type B breaker protecting the ring). However, with the No Trip facility switched off, the reading was a much more acceptable (and realistic) 0.43 Ohms.
So, long-wnded question, but can anyone throw some light on this for me? Until I've got it sorted, I'm definitely not going to trust the No Trip readings on this meter.
Cheers.
