Moved into an old house, and I'm turning things off at the MCB + using a socket tester to see what's on each circuit from the CU (the stickers aren't particularly helpful). I saw something odd: there's a set of sockets (4 doubles) in the basement that leave the socket tester partially lit even after I turn the MCB off for that circuit, and also even after I trip the RCD for all the MCBs on that RCD.
1 LED stays faintly green when the MCB is off; it turns to a faint red when the RCD is off, whether or not the MCB is on or off. This doesn't correspond to anything shown on the tester's labelling. What might be happening?
With both the MCB and RCD on (i.e when the circuit is live), all lights are green - all OK.
The tester is a TIS 100. The faint red/green light is the leftmost one.
I appreciate that I presumably need to get an electrician in, but I'd like to have an informed discussion with him/her based on this site's collective wisdom! Plus, if it's as simple as checking the wiring in the four sockets, or replacing them (they're old), maybe I can try that first.
I have a decent multimeter, so I can do some (safe) further testing if that would be sensible.
1 LED stays faintly green when the MCB is off; it turns to a faint red when the RCD is off, whether or not the MCB is on or off. This doesn't correspond to anything shown on the tester's labelling. What might be happening?
With both the MCB and RCD on (i.e when the circuit is live), all lights are green - all OK.
The tester is a TIS 100. The faint red/green light is the leftmost one.
I appreciate that I presumably need to get an electrician in, but I'd like to have an informed discussion with him/her based on this site's collective wisdom! Plus, if it's as simple as checking the wiring in the four sockets, or replacing them (they're old), maybe I can try that first.
I have a decent multimeter, so I can do some (safe) further testing if that would be sensible.
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