Pendant wiring maximum load

[noaliasmike]

Hi All,

I've just purchased a new lampshade weighing 1.7 KG.

On the side of the packaging it says to check "pendant wiring is suitable for this load"

I just have a standard pendant lamp light fitting - Is this sufficient to hold a 1.7KG load?

Thanks,

Michael

 

[crystal ball]

I had this problem last year and I seem to think I found the info from Hager, either on the website or their technical helpline

 

[JohnW2]

I've just purchased a new lampshade weighing 1.7 KG. On the side of the packaging it says to check "pendant wiring is suitable for this load" I just have a standard pendant lamp light fitting - Is this sufficient to hold a 1.7KG load?

The regulations indicate that 0.5mm² flexible cable can carry a maximum load of up to 2kg and 0.75mm² cable a maximum of 3kg. So, on that basis, even 0.5mm² would be OK for your lampshade. However, the crucially important thing would be to ensure that the support ('strain relief') of the cable at the ceiling rose was adequate to support the weight without pulling the wires out. You certainly should not rely on the electrical terminals of the ceiling rose to carry the weight - roses have various ways of providing 'strain relief' for the cable.

Kind Regards, John

 

[333rocky333]

as well as the strain relief in the Lampholder

 

[JohnW2]

as well as the strain releif in the Lampholder

Yes, that too. ... no point in the cable remainly firmly connected to the rose if the lampholder and shade come crashing down to the ground! The OP's problem may be in finding any definitive information on what load the strain relief of roses and lampholders can cope with.

Kind Regards, John

 

[noaliasmike]

Thanks for the replies. I will take the precaution of adding some sort of strain relief inside the ceiling rose to make sure it doesn't pull the wires out of the terminals.

Something like this looks like it will do the job:

What is the technical term for this device? If I pop into somewhere like Homebase what am I looking/asking for?

Thanks again.

 

[noaliasmike]

as well as the strain releif in the Lampholder

Yes, that too. ... no point in the cable remainly firmly connected to the rose if the lampholder and shade come crashing down to the ground! The OP's problem may be in finding any definitive information on what load the strain relief of roses and lampholders can cope with.

Kind Regards, John

I think I'll make the assumption that I need the support for both. There's a £600 glass table directly beneath it so there's no point in taking risks here.

What sort of strain relief options are available for securing the lampholder?

Thanks.

Edit: It's a standard Bayonet Cap holder by the way.

 

[JohnW2]

Thanks for the replies. I will take the precaution of adding some sort of strain relief inside the ceiling rose to make sure it doesn't pull the wires out of the terminals. Something like this looks like it will do the job:

What is the technical term for this device? If I pop into somewhere like Homebase what am I looking/asking for?

I don't think you'd get anything like that inside a ceiling rose - what exactly do you have on your ceiling? I don't think you'd get anything like that in the likes of Homebase.

Standard ceiling roses usually have lugs to wrap the wires around to provide strain relief. Lampholders usually have the same, plus and arrangment whereby the cover of the holder 'squashes/grips' the wires when screwed on (similar can apply with the covers of roses). What I don't know, in either case, is what weight/force they are designed to be able to stand.

Given the glass table, is there any way you could implement some sort of 'safety chain/wire' (maybe wound around the pendant cable?) from ceiling to the lampshade itself in a manner that was aesthetically acceptable?

Kind Regards, John

 

[333rocky333]

Another aditional aid i have used in the past is tight cable ties around the cable within the accesories
alternatively a hook base, chain and hooked lampholder, similar to pubs and restaurants is sometimes the only way for heavy shades

 

[Chri5]

No one seems to have discussed the actual method used at the moment to fix the ceiling rose to the ceiling.

Is it fixed in to a juicy joist or a well supported noggin above the ceiling?

If its plugs or dry line fixings then the whole lot will get pulled out when you put the new weighty fitting on.

 

[bernardgreen]

The weight limits giving for fittings are almost always for STATIC loads and take no account of DYNAMIC forces ( loads ) due to movement.

If the ceiling is liable to vertical movement from people bouncing around on the floor above then dynamic loading has to be considered.

With a £600 glass table underneath I would not rely on just a standard ceiling rose where the cover is held by a screw thread formed in the pliable plastic that some roses are made from.


Safety chain to a fixing into a joist is a good idea.

 

[noaliasmike]

It's just a standard ceiling rose I think? I've just opened it up and I can see what you mean about not being able to fit that hook contraption I posted above. The blue and brown wires do, however, already seem to be wrapped around a piece of plastic. Is this enough to provide the support? Picture:

The lamp holder however doesn't seem to have any support. The cables just get funneled up a piece of plastic but they're not wrapped around anything else:

 

[noaliasmike]

No one seems to have discussed the actual method used at the moment to fix the ceiling rose to the ceiling.

Is it fixed in to a juicy joist or a well supported noggin above the ceiling?

If its plugs or dry line fixings then the whole lot will get pulled out when you put the new weighty fitting on.

I'm sorry I have no idea which it is. Are you able to tell from the picture I posted?

 

[333rocky333]

No one seems to have discussed the actual method used at the moment to fix the ceiling rose to the ceiling.

The head of the fixing screw does look small actually

 

[DetlefSchmitz]

If I'm not sure what something will take, I usually load test it. If you try suspending a weight twice what you are expecting to support and see it if falls off the ceiling then it is likely to take the nominal load.

I did some similar tests to check the screws I was going to use for a juliette balcony, by supporting two concrete building blocks (duct taped together) from one of the fixings in question.

Apart from proving that they withstood twice the design load, it also demonstrated how incredibly strong duct tape can be.