Ask an Electrician anything...

[Regbuser]

The symptom is the failing equipment. And different types of equipment at that.
The equipment doesn't fail when tested by the mfr.
Therefore the fault is within the installation.
If the contractor went pop, that's not encouraging that they had the competency for design (nor installation).
A competent designer would be knowledgeable as regards Chapter 44 of the 18th edition wiring regs, amendment 2, be cognisant of the BS EN IEC 61000 series, and may also have attended mfrs design brief events to pick up the particular considerations required so as to avoid the problems your block of flats are experiencing.
There may also be one or two installation shortcomings, and incorrectly terminated cabling with an odd poor connection can play havoc with LED systems, as they are very sensitive to supply reference disturbance.
I'd be looking to have an M&E contractor review the designs first, then have their qualifying supervisor and a couple of techs pick over one dwelling in order to see how the design was installed.
It won't be cheap.

Edited by Regbuser on Friday 3rd November 06:26

[Teddy Lop]

Raj28 said:

Are there any CSI type electricians which specialise in finding and tracing down obscure issues? If so, can anyone recommend someone near London?

Summary:
New build block of flats
A number of residents getting issues with some LED dimmers (predominantly bathroom ones, though others do sometimes play up).
GU10 240v lamps. Lamp and dimmer manufacturer confirmed compatibility. Dimmer manufacturer re-tested lamps (we supplied) and reconfirmed compatibility.
Symptoms include:
Dimmer failure (have to reset MCB)
Dimmer failure (replace dimmer)
Lights come on then go off
Light come on, flash rapidly, then go off
Lights come on but some dim some bright (bright/flickering positions can be inconsistent)
Lights come on but some bright and others flickering (bright/flickering positions can be inconsistent)

Even when the dimmers have been replaced with a different type completely (same manufacturer, different tech), the issue is still present.
Dimmer manufacturer has inspected failed dimmers and said they think it's some kind of site specific interference.
I am inclined to agree as there have been quite a few PIR failures as well, and those almost never go wrong.

Struggling to think of anything along the lines of installation faults that could result in this without other symptoms, it's quite bizarre.

It's unlikely a dimmer would knock out an MCB, more likely a bulb, when the dimmers fail do you have failed lamps too? Some lamps fail hard, by which I mean short circuit, which can easily wreck both dimmers and PIRs and trip MCBs. Are you both dimming and PIR-controlling lights together?

I would take whatever the manufacturer says about their product with a pinch of salt, especially if it's aurora.

But bulbs would be my first suspect and as a (relatively) low cost experiment it may be worth changing a load to a different brand?

[mickk]

I too would look at a complete lamp change on a single flat (if you haven't already) before you do anything else. The manufacture isn't going to blame his equipment.

[silentbrown]

Replace dimmers with regular switches is the easy option

[ruggedscotty]

silentbrown said:

Replace dimmers with regular switches is the easy option

depends - if its network addressed wiring that wont work.... may find behind the switch two wires connecting to the pcb in the switch.
put a switch on that then the system shorts and it affects other lighting....

[cayman-black]

I,m really not sure what this is in my Bathroom ?Is it for the extractor? thx.

[silentbrown]

cayman-black said:

I,m really not sure what this is in my Bathroom ?Is it for the extractor? thx.

Temperature sensor for UFH, I think?

https://www.johnguest.com/gb/en/products/jg-underf...

[cayman-black]

Thanks silent could well be.

[Raj28]

Teddy Lop said:

Raj28 said:

Are there any CSI type electricians which specialise in finding and tracing down obscure issues? If so, can anyone recommend someone near London?

Summary:
New build block of flats
A number of residents getting issues with some LED dimmers (predominantly bathroom ones, though others do sometimes play up).
GU10 240v lamps. Lamp and dimmer manufacturer confirmed compatibility. Dimmer manufacturer re-tested lamps (we supplied) and reconfirmed compatibility.
Symptoms include:
Dimmer failure (have to reset MCB)
Dimmer failure (replace dimmer)
Lights come on then go off
Light come on, flash rapidly, then go off
Lights come on but some dim some bright (bright/flickering positions can be inconsistent)
Lights come on but some bright and others flickering (bright/flickering positions can be inconsistent)

Even when the dimmers have been replaced with a different type completely (same manufacturer, different tech), the issue is still present.
Dimmer manufacturer has inspected failed dimmers and said they think it's some kind of site specific interference.
I am inclined to agree as there have been quite a few PIR failures as well, and those almost never go wrong.

Struggling to think of anything along the lines of installation faults that could result in this without other symptoms, it's quite bizarre.

It's unlikely a dimmer would knock out an MCB, more likely a bulb, when the dimmers fail do you have failed lamps too? Some lamps fail hard, by which I mean short circuit, which can easily wreck both dimmers and PIRs and trip MCBs. Are you both dimming and PIR-controlling lights together?

I would take whatever the manufacturer says about their product with a pinch of salt, especially if it's aurora.

But bulbs would be my first suspect and as a (relatively) low cost experiment it may be worth changing a load to a different brand?

Sorry, I wasn't clear - the dimmer stops working (according to manufacturer this is overload protection, but only 3 or 4 5w lamps on it so nowhere near overload), and to get the dimmer working again you have to turn off and turn on the lighting breaker in the fuse board.

Lamps working after resetting the dimmer via the fuse board, lamps have been replaced to test, also compatibility tested by dimmer mfr twice. No dimming of PIRs.

All the lamps in the building were swapped out to a different brand during the build due to compatibility issues so the current ones have been tested twice (one back then and then again after these issues started).

To discount supply side issues a 7 day monitoring of the incoming supply is being carried out next week by UKPN. I think this covers voltage and harmonics from what the guy said.

It's strange as not all flats are impacted, with 1 particular flat many times worse than all the others, so I don't think it's the lamps this time.

It is a mystery, but will keep this thread updated - essentially going to be a process of elimination. Am very curious myself as to what will happen!

[Regbuser]

Further to this:

The apartment block has a fire alarm system, and this is unaffected?
Ditto, door access system?
Is there a lift system?
Is there a UPS?
Is there telecoms equipt on the roof?
Is there solar PV on the roof?

[Teddy Lop]

Raj28 said:

Sorry, I wasn't clear - the dimmer stops working (according to manufacturer this is overload protection, but only 3 or 4 5w lamps on it so nowhere near overload), and to get the dimmer working again you have to turn off and turn on the lighting breaker in the fuse board.

Lamps working after resetting the dimmer via the fuse board, lamps have been replaced to test, also compatibility tested by dimmer mfr twice. No dimming of PIRs.

All the lamps in the building were swapped out to a different brand during the build due to compatibility issues so the current ones have been tested twice (one back then and then again after these issues started).

To discount supply side issues a 7 day monitoring of the incoming supply is being carried out next week by UKPN. I think this covers voltage and harmonics from what the guy said.

It's strange as not all flats are impacted, with 1 particular flat many times worse than all the others, so I don't think it's the lamps this time.

It is a mystery, but will keep this thread updated - essentially going to be a process of elimination. Am very curious myself as to what will happen!

Power quality monitoring is something you can do yourself too, even down to circuit level (bad batch of breakers? Lots of junk out there today with no QC), supply is getting worse and is my theory why surge devices are stipulated now (which are worth considering if not already fitted), but I'd be surprised if an external problem was affecting only lighting. Loss/loose neutral connections can do all sorts of weird things.

Ultimately dimming of led bulbs is bread and butter, there should be little to go wrong and talk of design parameters is a bit highfalutin.

[Regbuser]

A little reading discovers this useful guide for trouble shooting network controlled lighting systems > https://lightingcontrolsassociation.org/2019/12/27...

You can download the excel spreadsheet by clicking through on a link here > https://lightingcontrolsassociation.org/resources/

[GTS_uk]

Replacing built in, plug in oven with hard wired.

Hi. Wondering if anyone had a minute to offer some guidance here pls.

I live in a relatively new build (5 yrs old) and looking to replace the two built in single ovens.
They both connect with a 3-pin plug. They have individual isolation switches and connect to individual 32amp RCDs.

The new ovens are hard wired only.

Can I assume it’s just a case of replacing the plug sockets with a spur to connect the oven?
I’m competent doing the wiring (and have the spec for the oven > spur cable) wanted to check on the regs/config.
Thanks in advance.

[ruggedscotty]

GTS_uk said:

Replacing built in, plug in oven with hard wired.

Hi. Wondering if anyone had a minute to offer some guidance here pls.

I live in a relatively new build (5 yrs old) and looking to replace the two built in single ovens.
They both connect with a 3-pin plug. They have individual isolation switches and connect to individual 32amp RCDs.

The new ovens are hard wired only.

Can I assume it’s just a case of replacing the plug sockets with a spur to connect the oven?
I’m competent doing the wiring (and have the spec for the oven > spur cable) wanted to check on the regs/config.
Thanks in advance.

ok....

oven rating. ? what does the instruction book state as the feed for each oven

existing you said 3 pin plug. is it a 13A style plug ?

32A RCD - unless its an rcbo then an RCD isnt an overcurrent, its differential. more than 30mA device will trip. 32a is the rating of the load capacity.

Ive seen ovens wired back to consumer unit and individual 16A MCB for each one. id run 2.5mm twin and e to the outlets. over rated but i dont know how far from the kitchen your consumer unit is.

what your saying is to swap out the socket to spur, that would be fine if cable is flex. i like to keep plug socket though as it lets me pull out the oven for cleaning fixing etc.

[Schwarz930]

Shaver Socket.

Can the feed come from the lighting circuit?

Or are they normally fed from a socket circuit or even a dedicated circuit?

Thanks.

[miniman]

Schwarz930 said:

Shaver Socket.

Can the feed come from the lighting circuit?

Or are they normally fed from a socket circuit or even a dedicated circuit?

Thanks.

Mine runs from lighting circuit.

Which means I probably shouldn’t have intercepted the feed to run a TV

[GTS_uk]

ruggedscotty said:

ok....

oven rating. ? what does the instruction book state as the feed for each oven

existing you said 3 pin plug. is it a 13A style plug ?

32A RCD - unless its an rcbo then an RCD isnt an overcurrent, its differential. more than 30mA device will trip. 32a is the rating of the load capacity.

Ive seen ovens wired back to consumer unit and individual 16A MCB for each one. id run 2.5mm twin and e to the outlets. over rated but i dont know how far from the kitchen your consumer unit is.

what your saying is to swap out the socket to spur, that would be fine if cable is flex. i like to keep plug socket though as it lets me pull out the oven for cleaning fixing etc.

Thanks for your help here.

According to the manual - The max loading is 3.5kW
My existing ovens have 13A style plugs, and you're right, wrong terminology from me re RCD. 32A on each oven 'breaker' in the consumer unit.
New oven says 16A, so they may need changing. Also says "hard wired only'.
For reference, this is the new oven in question - https://www.aeg.co.uk/kitchen/cooking/ovens/oven/b...

I'd assume as they are plugs, on an oven circuit and on a new(ish) build - they should be wired with 2.5mm twin and earth already? I guess I'll see when I take the oven out!

On the assumption that's the case, and with a switch to 16A, sounds like it should be ok?

Thanks again for your help here!

Looks like I should be
So, in principle, swapping the socket for a spur and

[Raj28]

Regbuser said:

Further to this:

The apartment block has a fire alarm system, and this is unaffected?
Ditto, door access system?
Is there a lift system?
Is there a UPS?
Is there telecoms equipt on the roof?
Is there solar PV on the roof?

Fire alarm not impacted.
Door access fine.
Single lift, variable speed drive.
No UPS.
No telecoms on roof.
Yes, solar PV on roof.

Ref the links, thank you. It isn't an addressable system but will look it further. This is all well above my head, but am trying to find a knowledgeable consultant to assist.

[Raj28]

Teddy Lop said:

Power quality monitoring is something you can do yourself too, even down to circuit level (bad batch of breakers? Lots of junk out there today with no QC), supply is getting worse and is my theory why surge devices are stipulated now (which are worth considering if not already fitted), but I'd be surprised if an external problem was affecting only lighting. Loss/loose neutral connections can do all sorts of weird things.

Ultimately dimming of led bulbs is bread and butter, there should be little to go wrong and talk of design parameters is a bit highfalutin.

Agree with your sentiment. Until we get someone on board I am following the initial informal advice I'm getting. From this it looks like it'll be UKPN first, then assuming no issues, someone clever will look at the LV distribution and then down to apartment level.

I don't think there is any SPD either at the incoming or in each apartment currently.

Will update the thread again as things play out. Thanks.

[DoubleSix]

Hello!

I want to buy these dimmers to control the LED strips in my new kitchen.

However, the discription says “not compatibile with lights using transformers or drivers”… which seems a bit odd as most LEDs use those no?

https://www.dowsingandreynolds.com/shop/triple-dim...