nuttytechy Posted April 18, 2018 Share Posted April 18, 2018 Hey, A maximum load on a 13amp is 3120 watts. 240 X 13 = 3120. It depends on the lighting you are using, 1KW = 1000 watts, 2KW = 2000 watts and etc. As the venue details is vague then we need to cover all scenarios. There may not be a dedicated ring for equipment, say for example you are in a working mens club and they are like "Its fine, Use our sockets etc for your gear"...... Their sockets are on a ring main which is also being used behind the bar. If their ring main MCB is 32 amps then a max load of 7680 watts can be used on that circuit so its not just your gear then there are their fridges, Dishwasher etc on that same circuit. *** I have seen one place where they got cowboys to wire a place **** Even with village halls, You set up your gear then Mary and Ethal come along with their tea-urn/s, plug it in then turn it on. There goes the power because they decided to have a tea urn either side of the room or used a double socket. ***sorry about the Tea-Urn thing ** laughs out loud ***** Just remember, If in doubt then consult someone who is qualified. Link to comment Share on other sites More sharing options...
themadhippy Posted April 18, 2018 Share Posted April 18, 2018 grrrr they lied to you at school,power=volts x amps is fine on dc,proper power is volts x amps x cos thingy otherwise you just end up with VA's Link to comment Share on other sites More sharing options...
adam2 Posted April 18, 2018 Share Posted April 18, 2018 I would again state that the maximum is about 3,000 watts. Too many variables to expect any great accuracy. Actual mains voltage could be as low as 210 volts at the point of use or as high as 253 volts. Design voltage of the equipment is probably unknown, as are manufacturing tolerances. Add to that the fact electronic drivers or ballasts use more amps at a low line voltage, whereas incandescent lamps use less amps at a low line voltage, and it becomes even clearer that no great accuracy can be expected. ABOUT 3,000 Watts. Link to comment Share on other sites More sharing options...
Jivemaster Posted April 18, 2018 Share Posted April 18, 2018 "About 3000w" is a fair answer but be wary of other things on the ring main and be wary of switching 3000w of tungsten straight on, the surge may stress the fuse. When I relied on 13a sockets I used to consider 2000w a fair load per plug. I would consider this fair for worn sockets with cooked springs and twin sockets not really rated at 13a X 2. Link to comment Share on other sites More sharing options...
sandall Posted April 18, 2018 Share Posted April 18, 2018 All this repetition that 13A at a (very) nominal 240V roughly equates to 3kVA is rather ignoring the point that the OP was enquiring about a lighting rig, not how many electric fire bars he can run. He could even use 12 1kW Par-cans on a 13A socket if he wanted to do a 3-colour wash the old fashioned way (I'm sure a lot of us have had to do it), but NOT all at the same time !! Link to comment Share on other sites More sharing options...
sunray Posted April 18, 2018 Share Posted April 18, 2018 Haha yes, in church hall / village hall type venues the unexpected tea urn can be a show stopper... spent some time a few months ago trying to explain to someone why they couldn't run 3 tea urns off a 4 way extension. Oh how many time I have encountered this situation. My niche is public address and historically a lot of my work was outdoor fetes etc. Regularly I'd find half a dozen 'domestic' extension leads (and often 0.75mm or 1mm) trailing many 10's of metres across a field with several high power devices of which the classics are urns and kettles plugged into the 4 sockets of the final plastic reel. "Have you got a spare fuse?" was a far too common request, often shortly followed by "Have you got a spare extension lead?". I'd love to receive a £ for every time that I've explained that they couldn't run an urn on their setup let alone 2 urns and a kettle and a microwave and a couple of lights in their marquee. Several of my regular jobs started including the site temporary's and even lost the PA job but kept the electrical element. Most 13A double sockets are still only rated at 13A total. I have replaced many failed double sockets specifically installed to power 2 kitchen appliances, the classic being a double socket under the sink for the washing machine and the dishwasher or tumble drier. Running at 20A or so they often fail before the 13A fuse in the spur that feeds them. Link to comment Share on other sites More sharing options...
timsabre Posted April 19, 2018 Share Posted April 19, 2018 13a doubles have to be rated at least 20a for both, it's in the bs spec. Link to comment Share on other sites More sharing options...
paulears Posted April 19, 2018 Share Posted April 19, 2018 If you tour a rig of dimmer packs and you need to plug them into domestic outlets, then it's typical for the sensible person on arrival to do some detective work. Many public/commercial buildings now have numbers on the outlets showing where they are wired back to - so seeing a number of outlets all with the same number suggests they could be on the same breaker, so the practical tripping point is that breaker's labelling. Normally 32A, but sometimes much lower. I'm quite happy modifying my power needs to cope with whatever is available, but it needs monitoring. If you see the outlets you will be using all with the same labeling, then searching out one that is different can pay dividends. Detective work and common sense. 3KW of lighting seems a sensible maximum for a single socket that should be doable. With care you could have 6KW of available lighting and the cues can keep it below 3KW max. What we're talking about here seems 'beginner' or 'novice' nowadays, but my intro to lighting touring in the 70s had this problem every single place we went to. You would have to find the power, technical riders rarely existed, and if a site visit was impossible, then it was always interesting. Disconnecting an immersion heater in a church hall, or using the 30 or 45 Amp cooker supply was pretty common for me. Back then, Jim Laws was the expert on power in my neck of the woods, and he managed to always find power somehow. Even the BBC were expert bodgers. At 21and full of theory I watched as the gaffer on Songs of Praise removed the church's single 30A fuse and replaced it with a nail because the cameras needed far more lighting than today. The exposed wiring on the wall he'd tap at intervals with his hand to see how it was coping. I've always found it useful in a modern building to push the system you bring in to see at what total it trips. If you ask the venue representative if it can take 2 x 3KW, and they shrug, you just ask if we can test it, making sure they know where the breaker is, and if you get your 6KW total that's a good start. If it trips because you're already sharing the ring with a hidden away fan heater, it's best to find out. Link to comment Share on other sites More sharing options...
timsabre Posted April 19, 2018 Share Posted April 19, 2018 If you ask the venue representative if it can take 2 x 3KW, and they shrug, you just ask if we can test it, making sure they know where the breaker is, ...and can get to it. Or is it in a locked cupboard to which only the churchwarden has a key and he's on holiday in the Algarve at the moment? Link to comment Share on other sites More sharing options...
sandall Posted April 19, 2018 Share Posted April 19, 2018 Two recent examples - Big choral concert in a church with 13A sockets everywhere I needed to put stands. Unfortunately none were working (apparently they hadn't been for some time, but nobody had thought to mention that at the recce) & the only 2 that were working had hidden 4-way blocks plugged into them, one of which turned out to have the remote for all the nave lighting plugged into it ! Conference in a hotel suite where the RCBO for the ring-main was consistently tripping at about 3mA / 4A ("your gear is overloading our 32A trip, guv !"). Link to comment Share on other sites More sharing options...
timsabre Posted April 19, 2018 Share Posted April 19, 2018 Big choral concert in a church with 13A sockets everywhere I needed to put stands. Unfortunately none were working (apparently they hadn't been for some time, but nobody had thought to mention that at the recce) & the only 2 that were working had hidden 4-way blocks plugged into them, one of which turned out to have the remote for all the nave lighting plugged into it ! Sounds like most of the events I get involved with. Remind me why we do this again?? Link to comment Share on other sites More sharing options...
sandall Posted April 19, 2018 Share Posted April 19, 2018 Used to be the money; now I think it's mostly the reassurance that people think you can still hack it :huh: Link to comment Share on other sites More sharing options...
alistermorton Posted April 19, 2018 Share Posted April 19, 2018 Sounds like most of the events I get involved with. Remind me why we do this again?? Because we love it haven't learn our lesson. Link to comment Share on other sites More sharing options...
Owain Posted April 19, 2018 Share Posted April 19, 2018 its not just your gear then there are their fridges, Dishwasher etc on that same circuit. *** I have seen one place where they got cowboys to wire a place ****One pub I used to frequent, after the 'renovation' all the lights dimmed in synchronicity with the glass-washer operating. Link to comment Share on other sites More sharing options...
sunray Posted April 19, 2018 Share Posted April 19, 2018 13a doubles have to be rated at least 20a for both, it's in the bs specIt may be in the spec but there are still some out there with '13A total maximum load' moulded into the back of them. locked cupboard to which only the churchwarden has a key and he's on holiday in the Algarve at the moment?Oh how I wish this were written in jest. Link to comment Share on other sites More sharing options...
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