I have 2 ceiling lights (40w SES) that I want to put in our bedroom. I have a 2 gang switch already fitted (only 1 gang currently wired up). I looked in the shed to find some cable to use and I have run out of T&E, can I use 4 core PVC flex (3184YH 0.75mm) for a lighting circuit?
Can i use 3184yh flex in a lighting circuit?
- Thread starter iab026
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Do you really want to protect 0.75mm flex with a 6 amp MCB?
Do you really want to use flex wiring where the properties are unknown for the given application?
1mm or 1.5mm T&E cost pennies. Better to do it right.
Do you really want to use flex wiring where the properties are unknown for the given application?
1mm or 1.5mm T&E cost pennies. Better to do it right.
It would. depending on method of installation ( thermal insulation etc ) be acceptable with a 6 amp fuse. Though where a single run of triple and earth is needed getting the "right" cable would be better.
From the Permaniod data at http://www.permanoid.co.uk/products/flexible/318_309/
Style 3184Y
No. and Area of conductors 4 x 0.75mm2
Voltage rating 300/500V
Current Rating (Amps) 6
From the Permaniod data at http://www.permanoid.co.uk/products/flexible/318_309/
Style 3184Y
No. and Area of conductors 4 x 0.75mm2
Voltage rating 300/500V
Current Rating (Amps) 6
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433.2.1 Except where Regulation 433.2.2 or 433.3 applies, a device for protection against overload shall be installed at the point where a reduction occurs in the value of the current-carrying capacity of the conductors of the
installation.
To fit a FCU to fuse down would cost more than the correct cable. Likely there would be no problem as ceiling roses which are junction boxes are only rated at 6A so most houses will have lighting protected at 6A as a result. It is normal to use 0.75mm flex from ceiling rose to BA22d bulb holder with itself is rated at 2A however the bulb should have built in fuse and since the flex is less than 3 meters as a result it complies.
See
433.2.2 The device protecting a conductor against overload may be installed along the run of that conductor if the part of the run between the point where a change occurs (in cross-sectional area, method of installation, type of cable or conductor. or in environmental conditions) and the position of the protective device has neither branch circuits nor outlets for connection of current-using equipment and fulfils at least one of the following conditions:
(i) It is protected against fault current in accordance with the requirements stated in Section 434
(ii) Its length does not exceed 3 m, it is installed in such a manner as to reduce the risk of fault to a minimum, and it is installed in such a manner as to reduce to a minimum the risk of fire or danger to persons (see also
Regulation 434.2.1).
The phrase "Can I" I read as "Can I and comply with regulations" and I would say in answer unlikely. Although if you are asking if doing so would cause a problem then I would also say unlikely.
installation.
To fit a FCU to fuse down would cost more than the correct cable. Likely there would be no problem as ceiling roses which are junction boxes are only rated at 6A so most houses will have lighting protected at 6A as a result. It is normal to use 0.75mm flex from ceiling rose to BA22d bulb holder with itself is rated at 2A however the bulb should have built in fuse and since the flex is less than 3 meters as a result it complies.
See
433.2.2 The device protecting a conductor against overload may be installed along the run of that conductor if the part of the run between the point where a change occurs (in cross-sectional area, method of installation, type of cable or conductor. or in environmental conditions) and the position of the protective device has neither branch circuits nor outlets for connection of current-using equipment and fulfils at least one of the following conditions:
(i) It is protected against fault current in accordance with the requirements stated in Section 434
(ii) Its length does not exceed 3 m, it is installed in such a manner as to reduce the risk of fault to a minimum, and it is installed in such a manner as to reduce to a minimum the risk of fire or danger to persons (see also
Regulation 434.2.1).
The phrase "Can I" I read as "Can I and comply with regulations" and I would say in answer unlikely. Although if you are asking if doing so would cause a problem then I would also say unlikely.
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The wiring regulations discriminate between the use of flexible and cable.
The 3184 flex isn't considered suitable for fixed wiring unless additional mechanical protection and support is provided.
Once you have done this, as suggested, you may as well have bought the correct materials for less.
The 3184 flex isn't considered suitable for fixed wiring unless additional mechanical protection and support is provided.
Once you have done this, as suggested, you may as well have bought the correct materials for less.
I would be interested to know where it is stated that 3184 is not suitable for fixed wiring as I am told 12 core (11 + earth) is an option I can use to reduce the amount of "damage" to 490 year old joists in the cottage I am renovating.
That's interesting. We have a similar challenge on a listed 16th century manor house next month. Are you using the 12 core instead of multiple T&Es?
The plan is to use ELV ( 12 volt ) to the switches in the walls using alarm type cable to minimise the size of the cut in the wattle and daub walls. These circuits will be input to a custom built controller where all the 230 volt feeds to lights will be switched. 12 core will run from the controller to a distribution box where individual cables will run out to the lamps. PVC twin and earth for the ground floor and pyro for the lamps in rooms under the thatched roof.
Using ELV for the switches means antique switches can be used. Functions such as two way switching and more complex functions will be provided by the logic in the controller which will also fuse each lamp separately.
Using ELV for the switches means antique switches can be used. Functions such as two way switching and more complex functions will be provided by the logic in the controller which will also fuse each lamp separately.
Ah yes, that's an excellent way to do it. We have done such things in the recent past with a custom built controller. We used a bank of TRIACs to actually switch the lights (not to fade them) and 12 volts DC switch signals feeding opto-isolated relays in the controller to "gate" the TRIACs on/off. This allowed us to use alarm cable for the switching.
On the upcoming job the customer wants a Futronix P800 system which use ELV via 4 core cable from main controller to individual SP4 remote switches/display panels. The building is gradeII listed and listed as special interest in the local hamlet so we need to take great care with cable runs. It's really my sons job but he has never worked on a listed building so I am making sure we don't get on the wrong side of Heritage.
PS, did you know that you do not need to charge VAT on anything over and above maintenance on a listed property? No VAT on complete rewires etc.
I am using opto isolated inputs for the ELV from switches into a PIC processor and mechanical relays switching the 230 volt. Each switched lamp circuit has its own 2 amp fuse. Mechanical relays were chosen as they can be fitted in sockets and a failed one ( shorted lamp etc ) can be replaced without having to unsolder anything. Repair time is minimised.
Using the PIC processor enables functions such as two way switching to be set up without having to interconnect switches with strappers. It also provides multiple timer functions such that lights can be turned on manually and then they automatically turn off after a period of time.
PS the VAT situation is not very clear, I am VAT registered for my electronics design business but as this renovation is a private DIY project it seems I cannot as a private person reclaim the VAT on purchases as I did 30 years ago when we DIY built our house.
Using the PIC processor enables functions such as two way switching to be set up without having to interconnect switches with strappers. It also provides multiple timer functions such that lights can be turned on manually and then they automatically turn off after a period of time.
PS the VAT situation is not very clear, I am VAT registered for my electronics design business but as this renovation is a private DIY project it seems I cannot as a private person reclaim the VAT on purchases as I did 30 years ago when we DIY built our house.
STOP!!!
VAT is charged on rewires on listed buildings. Rewires are classed as maintenance and repair according to HMRC
http://customs.hmrc.gov.uk/channels...CE_CL_000513&propertyType=document#P896_85591
I'm currently rewiring a listed building for a customer (at a cost of around £30K) And we definately have to charge VAT.
I think you hjave missed sparkticus's point. It's not a matter of reclaiming VAT (on purchases of materials etc.) but, rather, that undertaking 'approved alterations' to a listed building are Exempt from VAT - i.e. for example, if you employ the services of a bullder, plumber or electrician for 'approved alterations' (and there are rules about what constitutes that, rather than 'maintenance'), they should charge you VAT at 0%.
For this purpose, an 'approved alteration is defined as:
- In most cases an approved alteration is an alteration for which listed building consent is both needed and has been obtained from the appropriate planning authority (or, in some circumstances, the Secretary of State) prior to the commencement of the work. In each case you will need to find out from your customer (or their architect or surveyor) to what extent the work you have been contracted to do has both required and received listed building consent.
Kind Regards, John.
Hi John
I will be talking to the VAT man later this week to see if there is a legal way I can recover some of the VAT now that I know the full extent of the very necessary work needed on the cottage.
If I ( owner of listed building ) had employed myself ( VAT registered sole trader ) to renovate the building then I ( sole trader ) could apply zero rating to some of the work and apparently reclaim the VAT that I ( sole trader ) had to pay on some of the materials.
But if I employ myself in oprder to reduce VAT liability then I am probably going to have to pay tax on the money I ( sole trader ) charge myself ( owner ) for labour as it is earned income.
I will be talking to the VAT man later this week to see if there is a legal way I can recover some of the VAT now that I know the full extent of the very necessary work needed on the cottage.
If I ( owner of listed building ) had employed myself ( VAT registered sole trader ) to renovate the building then I ( sole trader ) could apply zero rating to some of the work and apparently reclaim the VAT that I ( sole trader ) had to pay on some of the materials.
But if I employ myself in oprder to reduce VAT liability then I am probably going to have to pay tax on the money I ( sole trader ) charge myself ( owner ) for labour as it is earned income.
A lot of the stage dimmers these days are designed with the traics connected to the PCB via pcb mount terminal blocks, the traic over hangs the edge of the board where it is fixed into a big heatsink using a pan head self tapping screw. Might be an alternative to look into if you want to eliminate the clicking
They also tend to use the mulicore cable arrangement you suggest, oven something like SY with a high core count, although I gather there are specialist cables for just this purpose about. Ends are made off in socapex or lectriflex connectors if you need to make them disconnectable
I'm sure RF will be along in a moment...
The clicking isn't going to be a problem. It can even be a benefit.., a confirmation that the switch has operated something.
Almost all semi-conductor switches and / or the protection devices "leak" a small amount of current when they are off. This is often enough energy to make an energy saving lamp flash or LEDs to glow dimly but noticeable when the light is off.
Almost all semi-conductor switches and / or the protection devices "leak" a small amount of current when they are off. This is often enough energy to make an energy saving lamp flash or LEDs to glow dimly but noticeable when the light is off.
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