Yet Another Cycling Forum
Off Topic => The Pub => Topic started by: Beardy on 02 December, 2023, 07:04:31 pm
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This afternoon, while I was doing some electrickery stuffs, I was again struck by the inappropriateness of the screws used to fasten the wires in. Why are the terminating screws configured with slotheads and not some other head configuration that would hold the driver in the right place?
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I think it's a truism that electricians never have the right screwdriver. Hence those Pozi/slot-head hybrid screws you get on circuit breakers etc.
The solution appears to be Wago-style sprung terminals.
Complicated devices with a large number of screw terminals (heating controls, alarm panels and the like) demand a blood sacrifice in order to function properly. Slot head screws ensure that happens.
I assume the ubiquity of slot head on faceplate screws (those weird M3.5 things) is to do with preventing them getting rounded off by clueless DIYers and/or electricians with the wrong screwdriver.
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Why wouldn’t a brand new extractor fan work when one of those fancy screwdrivers confirm it is receiving electricity?
Asking for a friend who bought it off a leading online retailer. It looks cheaply made TBH.
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They are always cheaply made. Even the premium ones only last a handful of years (buy one with a 5 year guarantee and keep the receipt - you'll need it).
I think most are made to satisfy builders who are compelled to install them by the regs, but will be long gone when the fan craps out after a year or two.
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Why wouldn’t a brand new extractor fan work when one of those fancy screwdrivers confirm it is receiving electricity?
Asking for a friend who bought it off a leading online retailer. It looks cheaply made TBH.
the fancy screwdrivers use your body as an "earth" to use the electricity to light up
The reason you aren't hurt or electocuted by this is that the amount of current is tiny
So I would guess that the reason is that either the fan is jammed and will not turn or that the supply to the fan doesn't have two wires that work to make a ciruit
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Why wouldn’t a brand new extractor fan work when one of those fancy screwdrivers confirm it is receiving electricity?
Asking for a friend who bought it off a leading online retailer. It looks cheaply made TBH.
the fancy screwdrivers use your body as an "earth" to use the electricity to light up
The reason you aren't hurt or electocuted by this is that the amount of current is tiny
So I would guess that the reason is that either the fan is jammed and will not turn or that the supply to the fan doesn't have two wires that work to make a ciruit
I wonder if it's one of those designed to work via the light switch with a time delay. They can be tricky to wire up.
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Why wouldn’t a brand new extractor fan work when one of those fancy screwdrivers confirm it is receiving electricity?
Asking for a friend who bought it off a leading online retailer. It looks cheaply made TBH.
the fancy screwdrivers use your body as an "earth" to use the electricity to light up
The reason you aren't hurt or electocuted by this is that the amount of current is tiny
So I would guess that the reason is that either the fan is jammed and will not turn or that the supply to the fan doesn't have two wires that work to make a ciruit
I wonder if it's one of those designed to work via the light switch with a time delay. They can be tricky to wire up.
At a guess I think that is the problem! He is not an electrician. I did have brief look and then realised that neither am I.
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Why wouldn’t a brand new extractor fan work when one of those fancy screwdrivers confirm it is receiving electricity?
Those fancy screwdrivers confirm the presence of a voltage relative to your body, they don't necessarily confirm that your fan is receiving electricity. They're semi-useful as a check before sticking your fingers in what-you-thought-weren't-live terminals, but can be actively misleading when troubleshooting wiring.
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At a guess I think that is the problem! He is not an electrician. I did have brief look and then realised that neither am I.
I'm going to suggest that it's probably not wired up right.
They usually need a 3-core and earth cable, fed from a 3-pole fan isolator switch.
The 3 cores are: Perm Live, Switched Live and Neutral. All of these can be sourced from the lighting circuit. From the ceiling rose, in a loop-through system, or the switch wall-box in a neutral-to-the-switches system.
The Perm live is what actually runs the fan motor.
The Switched live is a control input that tells it to start. It will continue to run for a time after the Switched live goes off.
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Slothead screws are fine but you do need a good fitting screwdriver. The main problem is many taper in thickness.
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At a guess I think that is the problem! He is not an electrician. I did have brief look and then realised that neither am I.
I'm going to suggest that it's probably not wired up right.
They usually need a 3-core and earth cable, fed from a 3-pole fan isolator switch.
The 3 cores are: Perm Live, Switched Live and Neutral. All of these can be sourced from the lighting circuit. From the ceiling rose, in a loop-through system, or the switch wall-box in a neutral-to-the-switches system.
The Perm live is what actually runs the fan motor.
The Switched live is a control input that tells it to start. It will continue to run for a time after the Switched live goes off.
I installed a "delay fan" in our shower room a couple of months ago - having given my roll of 3 core + earth to friend I have effected a temporary fix by bridging the permanent and switched live on the fan - the switch is a pull-cord (too complex to get to the light circuit)
The way it's wired means that when I switch the fan on with the cord I continue to hold the pull for a few seconds and then pull it again to "switch off" the fan . . . which because it has a permanent live continues for the pre-set run on time. WIGRTI I'll sort out a proper permanent live.
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Slothead screws are fine but you do need a good fitting screwdriver. The main problem is many taper in thickness.
One of those things that's obvious only after someone explains it to you is that the longer a screwdriver is the easier it is to keep it properly perpendicular to the screw head. This makes a huge difference where slot-head screws are concerned.
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I really regret that the fan in our new bathroom is connected to the lighting circuit.
If I want a shower in the day, I have to close the blind in order to not frighten those in the street below. (Or the horses in the field beyond)
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There is the idea that longer screwdrivers have more turning force but I would have thought what matters is the diameter of the handle. Longer screwdrivers might wobble less at the tip if you only use hand, if you hold the shaft with one hand and press against the screw and the use the other just to turn, you shouldn't get much wobble, at least in theory.
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I regret not telling the wee bro to wire the new fan up to a different switch from the lighting circuit, really don't need 20mins of fan after dashing in for a pish.
The velux light tunnel does help on that front in summer but it's 6 hours of dullness season now.
Sent from my IV2201 using Tapatalk
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The trick when it comes to bathroom lighting is to have more than one lighting mode, so you can select full brightness for zit squeezing and cleaning the bath, but just enough at bladder o'clock to check for Big Hairy Spiders and see whether the toilet seat is down without ruining your night vision.
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As I find myself needing to avail myself of the facilities more often at stupid o clock, I'm starting to wish I'd done the same.
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We have a plug in night light in the kitchen of our 2-up 2-down, ostensibly to make sure we don’t take a header down the stairs that are directly outside the bedroom door. The kitchen has a glass door. But it means enough light spills upstairs to see what’s what.
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I find that when I use the bathroom in the night the light from the bedside lamp is enough for me. It's not direct light either.
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At a guess I think that is the problem! He is not an electrician. I did have brief look and then realised that neither am I.
I'm going to suggest that it's probably not wired up right.
They usually need a 3-core and earth cable, fed from a 3-pole fan isolator switch.
The 3 cores are: Perm Live, Switched Live and Neutral. All of these can be sourced from the lighting circuit. From the ceiling rose, in a loop-through system, or the switch wall-box in a neutral-to-the-switches system.
The Perm live is what actually runs the fan motor.
The Switched live is a control input that tells it to start. It will continue to run for a time after the Switched live goes off.
Thanks, I will pass that on! As a first time buyer of a property 'in need of updating' he can't afford to hire experts and can make a pretty good job without..