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Other Vintage Household Electrical or Electromechanical Items For discussions about other vintage (over 25 years old) electrical and electromechanical household items. See the sticky thread for details. |
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22nd Apr 2018, 5:19 pm | #21 |
Pentode
Join Date: Apr 2018
Location: Tyne and Wear, UK.
Posts: 168
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Re: Daisy Chain Mains Extensions
What is branching ?
I have not come across that before ? |
22nd Apr 2018, 5:54 pm | #22 |
Dekatron
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Location: Leominster, Herefordshire, UK.
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Re: Daisy Chain Mains Extensions
Example:
4 4way extensions plugged into a 4 way extension is branching, 5 4 way extensions plugged 1st one into the wall, 2nd on into the 1st and so on is daisy chaining. Actually no. of ways doesn't matter for daisy chaining but you can only branch if there's more than one!
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22nd Apr 2018, 6:10 pm | #23 |
Pentode
Join Date: Apr 2018
Location: Tyne and Wear, UK.
Posts: 168
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Re: Daisy Chain Mains Extensions
Thank you for that.
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22nd Apr 2018, 6:18 pm | #24 |
Dekatron
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
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Re: Daisy Chain Mains Extensions
I don't think there is anything plugged into one of the (few enough, and nowhere near where needed) wall sockets in my house that isn't an extension lead! And there are more extension leads plugged into them ..... and even them, sometimes .....
For computer and audio / video equipment with only modest current consumption, cascaded extension leads are very unlikely to be a problem. Especially with the UK's system of every socket being earthed and every plug fused. Just make sure to plug anything over a kilowatt into the nearest one to the wall. The second-level extension leads can be fused at 5A or even 3A, limiting loading to 1150 or 690W respectively and hopefully blowing only their own fuses in the event of a fault.It's all about If you stay within the wattage limits (3kW through a 13A fuse) and use only decent quality extension leads made with 1.5mm² flex, you will be fine.
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22nd Apr 2018, 7:06 pm | #25 |
Pentode
Join Date: Apr 2018
Location: Tyne and Wear, UK.
Posts: 168
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Re: Daisy Chain Mains Extensions
Thank you
If I could find an unwired mains extension with more than six sockets would be ideal. The ones I use are pro elec, Does anyone know if there are any of these available with more than six sockets ? |
22nd Apr 2018, 7:20 pm | #26 |
Moderator
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Location: Fife, Scotland, UK.
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Re: Daisy Chain Mains Extensions
Didn't a firm called Olsen in London make metal distribution strips with lots of MK sockets. Used to advertise in WW
Still on the go? David
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22nd Apr 2018, 7:41 pm | #27 |
Retired Dormant Member
Join Date: Dec 2007
Location: Shropshire, UK.
Posts: 3,051
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Re: Daisy Chain Mains Extensions
Olsen dis boards are really nice - my electronics bench is fitted with an example with its own double-pole MCB.
Having said that, one of its sockets feeds a couple of daisy-chained plastic multi-way extensions! |
22nd Apr 2018, 8:05 pm | #28 | |
Hexode
Join Date: May 2015
Location: Northampton, Northants, UK.
Posts: 380
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Re: Daisy Chain Mains Extensions
Quote:
"The Show Must Go On" > "Health & Safety". The average theatre fly floor is an excellent place to hunt for impromptu autotransformers constructed from nothing more than TRS. More seriously, perhaps that experience is why I'm not very concerned with "daisy chaining" since the lighting rig will be full of it, which is what the Grelcos I referred to earlier up the thread are for. They actually are now made so that you can't stack them (the "Snapper" type), which is why every theatre will have a good stock of splitters (1 plug, two trailing sockets). Mind you I stopped working in theatre in the 90s so I daresay it's all much more elfinsafety and so on. In my day you were being pedantic if you tried to achieve some kind of phase separation in the rig. Having said all that, the most unpleasant accident I ever experienced was grabbing a lantern that was bolted to a wooden set (hence no fortuitous earthing) whose live and earth wires had been reversed, presumably before the lighting hire company had put the "inspected and tested" sticker on it. |
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22nd Apr 2018, 8:38 pm | #29 | |
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Re: Daisy Chain Mains Extensions
Quote:
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22nd Apr 2018, 9:04 pm | #30 | |
Heptode
Join Date: Apr 2011
Location: Edinburgh, UK.
Posts: 805
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Re: Daisy Chain Mains Extensions
Quote:
https://olsondirect.co.uk/ Or a series of metalclad sockets with conduit couplers between them, cable gland at the end(s) all mounted on a nice piece of varnished plank. |
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22nd Apr 2018, 9:16 pm | #31 |
Pentode
Join Date: Apr 2018
Location: Tyne and Wear, UK.
Posts: 168
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Re: Daisy Chain Mains Extensions
I have looked on the Olson site before. There are so many options, I am not really sure what I need to be looking for. Curiously i noticed most have a coiled earth wire on the side of the extension next to the mains cable.
Is that meant to be connected to anything ? |
22nd Apr 2018, 9:51 pm | #32 | ||
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Daisy Chain Mains Extensions
Quote:
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22nd Apr 2018, 10:01 pm | #33 |
Nonode
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
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Re: Daisy Chain Mains Extensions
I must admit to daisy chaining in my den, but it's done on a load rated basis. The heaviest users -PC/lamp is on the first quad unit ,with printers/speakers /scanners on the following units. All my lead lengths are short. Biggest problem ,that is not advertised ( IMHO-well enough) is the eddy current heating effect of wind up type extension leads used for even low-moderate current consumption.
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22nd Apr 2018, 10:35 pm | #34 | |
Hexode
Join Date: May 2015
Location: Northampton, Northants, UK.
Posts: 380
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Re: Daisy Chain Mains Extensions
Quote:
Such niceties as worrying about phases were falling by the wayside as the theatre industry got more and more younger people with an influence from rock'n'roll touring who didn't tend to worry about the likes of it. I was a young'un too, but as I said with a very traditional first boss who saw himself primarily as an electrical engineer. Funny thing writing this, I can't remember the Duke Of Yorks (where I was myself chief LX) having any dip traps at all. I remember the elderly batten boxes on the fly floor that were still labelled with the batten colours (red, blue, amber, white) that fell to bits when you unplugged something (until they were replaced when I convinced management to pay for a ROH rewire) and I remember the awesome Strand Grandmaster still on its perch, but I can't remember any stage dips. I guess we must have just dropped tripes down from above, then daisychained |
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22nd Apr 2018, 10:51 pm | #35 | |
Pentode
Join Date: Apr 2018
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Re: Daisy Chain Mains Extensions
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22nd Apr 2018, 10:58 pm | #36 | |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
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Re: Daisy Chain Mains Extensions
Quote:
A quick lookup of the derating factors needed for "all cores loaded" in multiway cable will make the point...... for many cores (like in a wound up lead) derating to 25% or less of the single wire in free air rating will be needed. Stage dips are sockets in the floor. Usually under a cover with cable entry cutouts on its edge(s).
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22nd Apr 2018, 11:06 pm | #37 |
Hexode
Join Date: May 2015
Location: Northampton, Northants, UK.
Posts: 380
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Re: Daisy Chain Mains Extensions
A proper "dip trap" is a recessed plug box in the floor (containing your sockets from the dimmer outputs) with a trapdoor on it, so you can run your cables out of it (gaffer taped to the floor) to lanterns at stage level. The trapdoor will have cutouts for the cables to egress.
In practise, any plug box at stage level (e.g. on the walls) gets called a dip, whether under a "trap" or not. It's worth noting that wherever your outlets are, they are in the wrong place for any particular production. I think probably in the early days of electrical lighting of theatre it would be presumed you'd only be using some of the circuits, but in reality every show uses all of them. Hence the problems of phase separation Paul originally described. IIRC at the Dukes it was blue phase on the fly floor, yellow on stage and red front of house. And having written that, we must have had dips (to be on a phase at all) but for the life of me I can't remember them at all. Not that it matters, but now it's niggling me like mad. Maybe we didn't have any until the rewire (I'm pretty sure I had wall mounted plugboxes installed). Gaah. This is going to keep me awake tonight |
22nd Apr 2018, 11:38 pm | #38 |
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Re: Daisy Chain Mains Extensions
I imagine the presence of dips mostly depends on the basic stage electrical layout, which in turn partly depends on when the theatre was built or rebuilt. They are much more common in the small rep / arts centre theatres that were built in large numbers in the 70s, originally with 30 channel Strand thyristor boards of some description. My sixth form college (opened in 1970) had this setup in its large central lecture theatre.
I have no real experience with large houses or music venues. Presumably these now have hundreds of lighting channels with computer control, and it would be pretty pointless wiring all those to recessed sockets in the stage floor. Anyway, I'm taking the thread off topic. Back to daisy chained multiway sockets please. |
23rd Apr 2018, 10:00 am | #39 | |
Dekatron
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Location: Wiltshire, UK.
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Re: Daisy Chain Mains Extensions
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23rd Apr 2018, 4:46 pm | #40 |
Octode
Join Date: Jun 2013
Location: Fleet, Hampshire, UK
Posts: 1,765
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Re: Daisy Chain Mains Extensions
Some of this seems a little OTT considering the extension lead plugged into the mains socket will have a 13A fuse in the plug protecting it. Is chaining a few together going to add significant extra length when compared with the length of the socket cabling in a typical house? Also, if the earth connections in such extension boards are poor or plugs not wired properly, then they are not fit purpose, chained or otherwise.
I always thought these views came from the original multi socket blocks that plugged into a socket and had 2 or 3 sockets on them, because the originals were not fused, so very easy to overload a socket? |