Oh silly Sunray that was in my reply with this bit before I capitalised it for emphasis
Still silly Sunray for missing it
-
Looking for a smarter way to manage your heating this winter? We’ve been testing the new Aqara Radiator Thermostat W600 to see how quiet, accurate and easy it is to use around the home. Click here read our review.
Extractor fan timer is random
- Thread starter portuguesejohn
- Start date
Still silly Sunray for missing it
To answer the original issue, the random timing, I wonder if that earth wire is actually connected to anything at the other end?
Might the triggering of the SL, simply be due to the earth wire picking up a bit of voltage, enough to trigger the SL input on the fan?
Might the triggering of the SL, simply be due to the earth wire picking up a bit of voltage, enough to trigger the SL input on the fan?
Yeah I wondered about that - but it would surprise me. In a correctly-wired system, when the switch is off the SL is pulled to ground via the bulb. It's not tied to neutral. If you remove the bulb from the fitting, it's floating. Do fans come on randomly when bulbs are removed? Maybe they do, but I doubt it.
No, I've installed several with just a retractive switch and no light
Something not correct = bulb fitted or not, shouldn't make any difference at all. The fan should continue to be triggered to on , by the switch.
No, something is very wrong, and despite the earth wire being used as the SL, at the fan, I would suggest it hasn't been connected to anything at the lights ceiling rose, or it is connected to the earth terminal, and that is not then connected to a valid earth. The fan is simply being triggered, by random voltages, appearing on the earth wire.
I assumed that an RCD would trip faster than a MCB and offer greater protection. Years ago an electrician friend of mine was complaining about a builder who had wired in a series of plastic LED down lights and that he had snipped off all of the earths as the cable ran from one light to the next. I am pretty sure that he said that the earth cables should have been connected to each other. I may have misunderstood though.
If you mean because of an L to E fault then I don't think there would be much difference with a dead short fault.
Of course, the RCD will trip with a tiny L to E or N to E fault but their purpose is to protect people; not be a nuisance with tiny 'faults'.
RCDs do not trip with an L to N fault but the MCB will.
Would that be an argument for having a CPC in the way?
Well, conductors should never be snipped off.
They should be joined but if not used then it makes no real difference whether joined or not.
I can see nothing I write will change your mind that you think a CPC should be present but as the regulation specifically states that they should be present solely in case required for Class I items in the future, none of your reasons really apply regulation-wise; just personal opinion.
Is the cable at the fan flex, or T+E?
Are we REALLY certain that the green and yellow wire IS switched live, and not an earth that someone has wrongly put in the switched live terminal?
Doesn't quite compute to me.
Are we REALLY certain that the green and yellow wire IS switched live, and not an earth that someone has wrongly put in the switched live terminal?
Doesn't quite compute to me.
Post #1, includes a photo of the fan terminals. I looks like 3-core flex, with the earth wire, connected to the SL terminal.
That is a very, very common installation method for the SL so I have every expectation it is as it appears to be.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
