Ask an Electrician anything...
Discussion
eein said:
The whole thing about downlighters is actually about psychology and what's natural to humans. There's plenty of properly researched papers out there about this, and you can go to training courses in the lighting design industry and learn this.
At the simplest level, in the natural world the sky is the brightest thing when you're out and about, so it's most natural to humans to have brightness in their upper vision versus what's at eye level of low down. So downlighters (and some other styles of fittings on their own provide illuminated areas low down but a leave a dark ceiling, which is not natural. There's also relationships to how the body produces melatonin, not just the sheer intensity of lighting, but also the style.
Poor office lighting down like this will make employees more tired and depressed through the day. This is why in the late 90s there was a shift in design of suspended tub light fittings which used to have reflected all pointed down to also have some pointing up to bounce some of the light to the ceiling.
In a home environment this means you should balance down lighting with upwards lighting, at least for 'normal' lighting scenarios (ie not 'mood' lighting). You can up light either with dedicated additional fittings, or with different styles of downlighter, or even just with considered use of reflective surfaces to reflect the downlight back up.
This is also why you should paint ceilings with vinyl silk and walls with matt emulsion.
Very interesting an makes a lot of sense.At the simplest level, in the natural world the sky is the brightest thing when you're out and about, so it's most natural to humans to have brightness in their upper vision versus what's at eye level of low down. So downlighters (and some other styles of fittings on their own provide illuminated areas low down but a leave a dark ceiling, which is not natural. There's also relationships to how the body produces melatonin, not just the sheer intensity of lighting, but also the style.
Poor office lighting down like this will make employees more tired and depressed through the day. This is why in the late 90s there was a shift in design of suspended tub light fittings which used to have reflected all pointed down to also have some pointing up to bounce some of the light to the ceiling.
In a home environment this means you should balance down lighting with upwards lighting, at least for 'normal' lighting scenarios (ie not 'mood' lighting). You can up light either with dedicated additional fittings, or with different styles of downlighter, or even just with considered use of reflective surfaces to reflect the downlight back up.
This is also why you should paint ceilings with vinyl silk and walls with matt emulsion.
I work in a brand new office building, which has LED strip lights flush fitted into the ceiling in a way that fails to light the ceiling. We also have white desks which cause glare from the above lights and noticeable VDU fatigue (desk is brighter than the screen) and is generally poor.
The above adds to that and makes a lot of sense.
dhutch said:
eein said:
The whole thing about downlighters is actually about psychology and what's natural to humans. There's plenty of properly researched papers out there about this, and you can go to training courses in the lighting design industry and learn this.
At the simplest level, in the natural world the sky is the brightest thing when you're out and about, so it's most natural to humans to have brightness in their upper vision versus what's at eye level of low down. So downlighters (and some other styles of fittings on their own provide illuminated areas low down but a leave a dark ceiling, which is not natural. There's also relationships to how the body produces melatonin, not just the sheer intensity of lighting, but also the style.
Poor office lighting down like this will make employees more tired and depressed through the day. This is why in the late 90s there was a shift in design of suspended tub light fittings which used to have reflected all pointed down to also have some pointing up to bounce some of the light to the ceiling.
In a home environment this means you should balance down lighting with upwards lighting, at least for 'normal' lighting scenarios (ie not 'mood' lighting). You can up light either with dedicated additional fittings, or with different styles of downlighter, or even just with considered use of reflective surfaces to reflect the downlight back up.
This is also why you should paint ceilings with vinyl silk and walls with matt emulsion.
Very interesting an makes a lot of sense.At the simplest level, in the natural world the sky is the brightest thing when you're out and about, so it's most natural to humans to have brightness in their upper vision versus what's at eye level of low down. So downlighters (and some other styles of fittings on their own provide illuminated areas low down but a leave a dark ceiling, which is not natural. There's also relationships to how the body produces melatonin, not just the sheer intensity of lighting, but also the style.
Poor office lighting down like this will make employees more tired and depressed through the day. This is why in the late 90s there was a shift in design of suspended tub light fittings which used to have reflected all pointed down to also have some pointing up to bounce some of the light to the ceiling.
In a home environment this means you should balance down lighting with upwards lighting, at least for 'normal' lighting scenarios (ie not 'mood' lighting). You can up light either with dedicated additional fittings, or with different styles of downlighter, or even just with considered use of reflective surfaces to reflect the downlight back up.
This is also why you should paint ceilings with vinyl silk and walls with matt emulsion.
I work in a brand new office building, which has LED strip lights flush fitted into the ceiling in a way that fails to light the ceiling. We also have white desks which cause glare from the above lights and noticeable VDU fatigue (desk is brighter than the screen) and is generally poor.
The above adds to that and makes a lot of sense.
eein said:
Too many architect and building services design companies these days are overly concerned about their fit out designs 'looking cool' to take the time to skill up in the human side of their designs. It's just part of the woke superficial populist world we now live in. Hopefully Hybrid working and the need to attract workers to choose to come in to the office more will drive a trend to think more about the actual comforts to staff.
We have had a few 'how are people finding the office' questioners and I say the lighting is poor and desk create glare every time, but what can they do at this point? its a 600 person office, two wings three floors, are they about to change all the lighting and desks. No because it would cost a fortune. Would doing it right first time have cost any more, likely not. But it looks cool..... ... our company also has an bit focus on safety, and slips trips and falls are a huge percentage of our injuries due to the other half of the business being an old semi-derelict chemical works. The carpark for the new building looks likes Escher's "relativity" print there are that many stairs, often to no where, or going up in order to turn 90deg and come down again. All in granite and stainless steel hand rails, which are both slippy when wet, and the stainless is already rotting due to the winter grit salt. Again, form over function!
Just changing a knackered socket.
Time to remove old socket - 2 minutes
Time to wire in new socket - 5 minutes
Time to screw socket into backbox - tending to infinite...
What am I doing wrong? Is there a trick. or are all backbox screws just supplied intentionally too short to make this trivial?
Time to remove old socket - 2 minutes
Time to wire in new socket - 5 minutes
Time to screw socket into backbox - tending to infinite...
What am I doing wrong? Is there a trick. or are all backbox screws just supplied intentionally too short to make this trivial?
silentbrown said:
Just changing a knackered socket.
Time to remove old socket - 2 minutes
Time to wire in new socket - 5 minutes
Time to screw socket into backbox - tending to infinite...
What am I doing wrong? Is there a trick. or are all backbox screws just supplied intentionally too short to make this trivial?
Just posting to add the offer of a virtual beer for whoever can answer this with a decent 'knack'Time to remove old socket - 2 minutes
Time to wire in new socket - 5 minutes
Time to screw socket into backbox - tending to infinite...
What am I doing wrong? Is there a trick. or are all backbox screws just supplied intentionally too short to make this trivial?
Electricians I've used have always had a pack of the longer screws in the toolbox and instantly use them without even trying the default supplied ones. They also grumble about the standard ones being too short, especially if the first fit of the back box was flush to the wall structure and then plasterboard and skim brought the finished wall significantly further out.
As an amateur I have to technique and have experienced the infinite fiddling many times. Only once of twice I've noticed that the threads on the tip of the screw are worn and a fresh screw has helped, or some standard screws which have a 'bald' mm or two at the tip and changing for others in my draw of bits that don't have this has helped.
In some scenarios I have also resorted to ripping out the original standard depth box and putting in a deeper one, which then is flush to the plastered finished wall surface.
As an amateur I have to technique and have experienced the infinite fiddling many times. Only once of twice I've noticed that the threads on the tip of the screw are worn and a fresh screw has helped, or some standard screws which have a 'bald' mm or two at the tip and changing for others in my draw of bits that don't have this has helped.
In some scenarios I have also resorted to ripping out the original standard depth box and putting in a deeper one, which then is flush to the plastered finished wall surface.
BigBen said:
silentbrown said:
Just changing a knackered socket.
Time to remove old socket - 2 minutes
Time to wire in new socket - 5 minutes
Time to screw socket into backbox - tending to infinite...
What am I doing wrong? Is there a trick. or are all backbox screws just supplied intentionally too short to make this trivial?
Just posting to add the offer of a virtual beer for whoever can answer this with a decent 'knack'Time to remove old socket - 2 minutes
Time to wire in new socket - 5 minutes
Time to screw socket into backbox - tending to infinite...
What am I doing wrong? Is there a trick. or are all backbox screws just supplied intentionally too short to make this trivial?
Screws you need are M3.5mm. Problem is they are sold in packs, maybe a friendly electrical wholesaler will sell/give you a couple.
https://www.screwfix.com/c/screws-nails-fixings/el...
You an also get extension studs which make the job easy.
https://www.toolstation.com/extension-stud/p79641
Edited by megaphone on Tuesday 7th February 14:15
Edited by megaphone on Tuesday 7th February 14:16
megaphone said:
Screws you need are M3.5mm. Problem is they are sold in packs, maybe a friendly electrical wholesaler will sell/give you a couple.
https://www.screwfix.com/c/screws-nails-fixings/el...
You an also get extension studs which make the job easy.
https://www.toolstation.com/extension-stud/p79641
Cheers. Just ordered a job lot from the bay of evil .https://www.ebay.co.uk/itm/362805440306https://www.screwfix.com/c/screws-nails-fixings/el...
You an also get extension studs which make the job easy.
https://www.toolstation.com/extension-stud/p79641
The annoying thing here was that the screws I'd removed just wouldn't locate, even though they'd been fitted fine before. My hacksawed-down 70mm ones eventually worked OK, but the lead-in thread had inevitably got a little borked when I shortened them.
Don't cut the screws with a hacksaw, you won't get a clean cut. Use a crimp tool that has a cutter on. Dead easy, screw the screw into the cutter until the required length. Close crimp tool to cut off the waste and unscrew the screw which cleans the thread. https://uk.rs-online.com/web/p/crimp-tools/1367425
silentbrown said:
megaphone said:
Screws you need are M3.5mm. Problem is they are sold in packs, maybe a friendly electrical wholesaler will sell/give you a couple.
https://www.screwfix.com/c/screws-nails-fixings/el...
You an also get extension studs which make the job easy.
https://www.toolstation.com/extension-stud/p79641
Cheers. Just ordered a job lot from the bay of evil .https://www.ebay.co.uk/itm/362805440306https://www.screwfix.com/c/screws-nails-fixings/el...
You an also get extension studs which make the job easy.
https://www.toolstation.com/extension-stud/p79641
The annoying thing here was that the screws I'd removed just wouldn't locate, even though they'd been fitted fine before. My hacksawed-down 70mm ones eventually worked OK, but the lead-in thread had inevitably got a little borked when I shortened them.
https://www.screwfix.com/p/c-k-re-threading-tool-m...
julian64 said:
Why did sparkie who recent did some work to my house electrics, connect an earth to plastic water piping.
I asked him and he said 'regulations' . I said 'insulator', he said 'capacitor', I said 'you're joking'.
MadnessI asked him and he said 'regulations' . I said 'insulator', he said 'capacitor', I said 'you're joking'.
Though equally mad are some of the drain pipes from some sinks at work.
They are glass pipes with metal coupling clamps and each clamp is connected to the next one along with chunky earth wires.
Its not like we need equipotential bonding of our sinks at a power station, in fact in a large fault, its more likely to suffer from voltage differentials.
Another house. Another LED light issue.
All lights replaced. Now all LED. Hallway light will come on dimly in the middle of the night. Switch on then off problem sorted.
I was changing all the light switches the other day. Two of the rooms had the below bridging Com and L1 in the switches, I can't honestly remember what bulbs were in the rooms, halogen or LED. If it was LED then they were early LED bulbs.
I suspect they're a capacitor or diode, can any one advise? Where can I get more?
All lights replaced. Now all LED. Hallway light will come on dimly in the middle of the night. Switch on then off problem sorted.
I was changing all the light switches the other day. Two of the rooms had the below bridging Com and L1 in the switches, I can't honestly remember what bulbs were in the rooms, halogen or LED. If it was LED then they were early LED bulbs.
I suspect they're a capacitor or diode, can any one advise? Where can I get more?
Edited by Sir Bagalot on Sunday 12th February 21:56
Sir Bagalot said:
Another house. Another LED light issue.
All lights replaced. Now all LED. Hallway light will come on dimly in the middle of the night. Switch on then off problem sorted.
I was changing all the light switches the other day. Two of the rooms had the below bridging Com and L1 in the switches, I can't honestly remember what bulbs were in the rooms, halogen or LED. If it was LED then they were early LED bulbs.
I suspect they're a capacitor or diode, can any one advise? Where can I get more?
It's a neon, unusual to find in a light switch but some brands used them as a low light "locator". Would probably cause an led bulb issues like glow/flickerAll lights replaced. Now all LED. Hallway light will come on dimly in the middle of the night. Switch on then off problem sorted.
I was changing all the light switches the other day. Two of the rooms had the below bridging Com and L1 in the switches, I can't honestly remember what bulbs were in the rooms, halogen or LED. If it was LED then they were early LED bulbs.
I suspect they're a capacitor or diode, can any one advise? Where can I get more?
Edited by Sir Bagalot on Sunday 12th February 21:56
Teddy Lop said:
Sir Bagalot said:
Another house. Another LED light issue.
All lights replaced. Now all LED. Hallway light will come on dimly in the middle of the night. Switch on then off problem sorted.
I was changing all the light switches the other day. Two of the rooms had the below bridging Com and L1 in the switches, I can't honestly remember what bulbs were in the rooms, halogen or LED. If it was LED then they were early LED bulbs.
I suspect they're a capacitor or diode, can any one advise? Where can I get more?
It's a neon, unusual to find in a light switch but some brands used them as a low light "locator". Would probably cause an led bulb issues like glow/flickerAll lights replaced. Now all LED. Hallway light will come on dimly in the middle of the night. Switch on then off problem sorted.
I was changing all the light switches the other day. Two of the rooms had the below bridging Com and L1 in the switches, I can't honestly remember what bulbs were in the rooms, halogen or LED. If it was LED then they were early LED bulbs.
I suspect they're a capacitor or diode, can any one advise? Where can I get more?
Edited by Sir Bagalot on Sunday 12th February 21:56
Where can they be bought?
Hi guys,
Specific question about meter tails.
In order to prepare for some forthcoming works, I need to ensure I have a route for some new meter tails.
Existing meter cupboard on external wall, existing CU almost directly below in cellar (slightly side ways but only by about 1m).
Existing 25mm tails run out of the base of the meter box and through the cavity, through a hole in the inner blockwork (plugged with glass wool) and secured in to the CU with a tails gland.
Need to route three phase tails to an adjacent new three phase CU.
Total length will be 3m as in the existing installation.
Ordinarily I would think that running some ducting down the cavity (40mm) which would then take the new tails would be okay. I realise that some bricks might need to come out so I can rod down the cavity.
However, it appears the latest regs don't seem to like tails in the cavity. My electrician mate did mention this to me.
It isn't clear if this is just due to mechanical damage and cable support reasons.
Q1: Is it okay to use 40mm plastic flexible ducting (inside the cavity)?
Q2: Should it be metal Copex?
Q2a: Should that metal duct be earthed?
Q2b: Should that be earthed at at the CU end only with an isolation gland at the meter cupbord end?
Background to Q2b... The earthing is TN-C-S (PME), but also has an earth rod connected to the MET via 16mm cable (for forthcomming EVSE).
DNO will be connecting the tails, just don't want to fall foul of the regs for the cable routing.
Thanks
Specific question about meter tails.
In order to prepare for some forthcoming works, I need to ensure I have a route for some new meter tails.
Existing meter cupboard on external wall, existing CU almost directly below in cellar (slightly side ways but only by about 1m).
Existing 25mm tails run out of the base of the meter box and through the cavity, through a hole in the inner blockwork (plugged with glass wool) and secured in to the CU with a tails gland.
Need to route three phase tails to an adjacent new three phase CU.
Total length will be 3m as in the existing installation.
Ordinarily I would think that running some ducting down the cavity (40mm) which would then take the new tails would be okay. I realise that some bricks might need to come out so I can rod down the cavity.
However, it appears the latest regs don't seem to like tails in the cavity. My electrician mate did mention this to me.
It isn't clear if this is just due to mechanical damage and cable support reasons.
Q1: Is it okay to use 40mm plastic flexible ducting (inside the cavity)?
Q2: Should it be metal Copex?
Q2a: Should that metal duct be earthed?
Q2b: Should that be earthed at at the CU end only with an isolation gland at the meter cupbord end?
Background to Q2b... The earthing is TN-C-S (PME), but also has an earth rod connected to the MET via 16mm cable (for forthcomming EVSE).
DNO will be connecting the tails, just don't want to fall foul of the regs for the cable routing.
Thanks
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