I'm not great with electronics really. I'm more a mechanical guy but I think this is relatively simple:

 

I'm after running two lamp fixings off one plug, currently they obviously have a plug each. What's the best way to make this actually happen? Can I just get a spur type box and wire them both up in parallel and then have one cable off of that with a fused plug on?

 

I'm looking at a 150w bulb in one and a 50w bulb in the other if that makes any difference?

 

 

Everything in my brain is saying this would be fine and still totally safe. But I don't trust myself in any way to accept that without someone else's opinion.

 

(I know I could just get a 2way gang but I'm trying to reduce the physical size and cabling of everything as part of a larger project)

Yes, no problem, this is no different to a 2 gang extension lead; why not just wire them into one plug?? Most decent plugs will take two lamp cables as  they are designed to take 1.5-2.5mm cable, and the lamp cables would only be 0.5 - 0.75mm each, oval or flat cables would work better than round though, as the choke point would be the external insulation clamp.

The lamp cables are round, a specialist 2 core with silicone sleeving, so I'm not sure I'd get both into a single plug. Hence looking at a junction box type thing before the plug end.

My question is, are both these lamps portable and free standing, or are they fixed?  If fixed then maybe connect them to a spur type thing, if portable, why faff about trying to connect them together, I'd use as suggested, a 2/3/4 in line extension lead to give them power.

Both will be fixed in place (they're both just a rose really). But they're connecting to a normal 3 pin socket that supplies a variable voltage (dimmer) so I need them to both be running from one plug and ideally without extra cables/gangs as it's a tight space in the cabinet where the socket is fixed.

Maybe one of these?

 

https://www.amazon.co.uk/s/ref=nb_sb_ss_c_1_16?url=search-alias%3Daps&field-keywords=two+way+socket+adaptor&sprefix=two+way+socket+a%2Caps%2C141

GG & other electrical types on here will be better advised on insulation, but I'd look at two ways of doing this in limited space.

Both involve the use of heatshrink, and possible insulating tape to get the insulation to mains standard. I'm assuming that the wiring is all two wire.

1) - Twist the two Live ( brown ) leads of both together, and join to brown lead of extension cable. Solder all wires together, cover with heatshrink and heat down. Heat shrink should be good enough, but add a layer of insulation tape anyway. Do likewise to Neutral lead ( Blue) . Slide a length of larger heatshrink over the two joints, and heat to close. A layer of tape might be needed to maintain mains insulation.

2) - Joint using crimp sleeves, and insulate sleeves with heatshrink. Cover joint with heat shrink, and perhaps layer of tape.

Add mains plug to single cable.

If space is that tight, I would try to go outside of the cabinet with the socket, if the wiring is accessible - and fit a fused spur box that feeds to the socket box in the cabinet, then fit the dimmer to the existing socket box and wire the two lights into it.

 

I would also look at replacing the old filament bulbs with LED to reduce the heat build up in the cabinet - unless of course the heat is what you want.

Buy one of these, cut of the IEC plugs and rewire the lamp ends rather than the plug end?

https://www.amazon.co.uk/Netshop-Mains-Splitter-Sockets-overall-Black/dp/B00XAC9E66/ref=pd_vtph_147_tr_img_2?ie=UTF8&psc=1&refRID=Q38GJNMZVNDB71MJRPCK

I would also look at replacing the old filament bulbs with LED to reduce the heat build up in the cabinet - unless of course the heat is what you want.

 

To all intents and purposes neither bulb will give out any light so I'm pretty much only after the heat.

 

Buy one of these, cut of the IEC plugs and rewire the lamp ends rather than the plug end?

 

The bulb socket is a specialist ceramic fitting to cope with the heat from the bulb(s) and the cable that end needs to be heat, UV and moisture resistant too, so I'm not keen on changing the bulb end/cable at all or I'd definitely be doing something like this (which is why I also want to keep it simple on the fuse/plug end in case anything does go tits up).

 

The space constraint is in the plug area, so in-between the plug and the light fitting I have a lot more leeway. I was wondering if it'd be a better bet to solder and essentially make up a custom cable, or if a junction box would be easier. Might go the heatshrink way as VWD said and solder a custom cable. 

easy:-

 

   http://www.screwfix.com/p/chocbox/54936

 

Wire as show in pics, did this when fitting two LED strips to a cabinet, so two wires (one from each LED strip) into box, then one cable out from box to transformer plug (wall wart).

 

Can't remember it the box came with the terminals, as I have loads of them anyway.!!

In regards to VWD's response, neither heat shrink or insulation tape are actually rated as an insulator (remember, it's insulation MARKING tape) so if this project is to be used in a place of work it may fall foul of regulations if they were used for insulating purposes

Updown- THAT is why I did QUALIFY my response to include advice on the insulation needed to provide the required insulation needed to insulate the conductors at the required voltages. I've been working/qualified to work  on high voltage systems for a long time, and that was my advice- "INSULATE TO THE VOLTAGES NEEDED".

It wasn't a dig, just stating that neither product is suitable for use as an insulator as such. I just don't want anyone to be in trouble for using the wrong product.

For 240v electrical shrink-wrap is fine*, but I am assuming you will also be using a heat resistant glass fibre insulation -  or a heat resistant insulated cable - normal cable insulation will go brittle if you are using these as heat lamps.

 

Unless I am corrected - ie the regs have changed; shrink wrap used to be used for insulating 240v - 600v equipment when I was an industrial sparky.

We used to carry it for use on rail power stuff up to /including 650 VAC joints. I'd be wary of other types of insulation. I had many problems abroad with various types of sleeving, which ,although stood up to mains /mains + voltages, broke down on lightning strikes. Almost always Live- Earth, so my solution ( complete with warning notices, mainly to self) was to swap L & N over the section .(Remember that this was an emergency repair in the middle of no where in the middle of the night to keep trains moving).

Well, I think the chances of a lightening strike inside a cabinet, INSIDE a house, are fairly low, so shrinkwrap will do the job.

Only if it has the correct markings as a BS certified insulator though. 100m of heat shrink straight from ebay is unlikely to. Not wise in a workplace environment where the Chances of being sued if it burns down are high.