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eskimo39
Can anyone shed some light on this? I am at a customers house who has a 3 phase supply protected by a main RCD just after the suppliers meter and just before the main consumer unit.
Been having lots of problems with nuciance trips so tested the RCD today with my Megger RCDT320 on a ramp test.
The RCD is rated at 100mA. I connected the gree earth lead and then used the red probe (Phase) to the L1 terminal. The ramp test never tripped the RCD and showed >150mA.
The exact same reading on L2 again with no tripping.
On L3 the RCD tripped but the reading was 140mA.
I am guessing the RCD is faulty but am confused why the customer is still experiencing a lot of nuciance tripping as surely no tripping on L1 & L2 and a very high tripping current on L3 would cause less tripping???
If I install a new 3P RCD which trips correctly on L1,L2 & L3 won't this just trip more??
Another problem that may be connected is I have installed a single phase consumer unit on L3 which feeds gates and exterior lights. I tested the 30mA RCD in this which tripped correctly at 24mA and in .20 seconds. However it also caused the main 3 Phase RCD to trip as well??
Heeeelp
Been having lots of problems with nuciance trips so tested the RCD today with my Megger RCDT320 on a ramp test.
The RCD is rated at 100mA. I connected the gree earth lead and then used the red probe (Phase) to the L1 terminal. The ramp test never tripped the RCD and showed >150mA.
The exact same reading on L2 again with no tripping.
On L3 the RCD tripped but the reading was 140mA.
I am guessing the RCD is faulty but am confused why the customer is still experiencing a lot of nuciance tripping as surely no tripping on L1 & L2 and a very high tripping current on L3 would cause less tripping???
If I install a new 3P RCD which trips correctly on L1,L2 & L3 won't this just trip more??
Another problem that may be connected is I have installed a single phase consumer unit on L3 which feeds gates and exterior lights. I tested the 30mA RCD in this which tripped correctly at 24mA and in .20 seconds. However it also caused the main 3 Phase RCD to trip as well??
Heeeelp
