Terminating lighting fixtures

T

theuniverseinanutshell

Member
For ease of use and flexibility, any advice on the most optimal way of terminating lighting cable? Keeping in mind that I am based in the UK and would be initially using the lights at home — though, as mentioned, looking in the long-term and on-location use — what type of plug should I be using? On the Arri 650w I bought was an in-line power switch; is that also mandatory? Would appreciate some help!

Regards,
J
 
An inline power switch is not absolutely necessary, but will work to keep your gear functional, as plugging it in hot creates an arc between the two plugs and could damage them. You might want to look into the electrical code though, as maybe your region requires it.

As far as the plug to use in the uk, that's a great question.
 
Inline switches are easy to overlook until you have a fixture without one. It's really a pain to deal with gelling and adjusting if someone has to dig around for the plug and pull it. Tungsten filaments can break pretty easily when bumped while hot, unless it's a really smooth and simple adjustment it's wise to turn 'em off when raising, lowering, moving the whole unit & stand setup. Big slowdown on set to blow a globe and wait for the fixture to cool.

In the US, you have the option of 120v/15amp household plugs; then there's the 20amp circuits which can still take a 15amp male plug. When you move up to higher amperage distro systems you often end up with bates connectors (and most theaters with professional setups use bates). Not sure about the UK, but in the US, if it's under 15 amps you'd max at a 1k fixture with other stuff on the circuit. You'd use heavy duty, grounded (3 prong) household plugs. (maybe a 2k will run on a clean 15amp household circuit with good wiring and a good breaker, and nothing else plugged in, but it's not a great idea) 1k with other stuff on the circuit you'd keep it heavy duty, grounded (3 prong) household plugs.

Some of my biax flos use 2-prong lightweight plugs, but they're pulling 110 watts and are double-insulated (or hopefully they are!)
 
For video, with the usual longer cable lengths, the inline switch is pretty essential really, and if you don't use it, it doesn't hurt.

As I do video and theatre work, I used to have a connector problem. The theatre standard was (and still is for dimmers) 15A, and TV mainly 16A. Yet, if you visit any homes or business premises, you're needing 13A. As moving head kit and LED equipment that is DMX controlled cannot be connected to dimmers, 16A has for me become standard. I just have 13A plug to 16A socket short cables to connect up. I've also got 16A plug to 13A socket, and even a few that end up in 15A sockets so I can use my theatre stuff too.

16A connectors are easy to put on, and cheap. I also have a number of different size distros - so I can connect to single and three phase supplies in 16/32/63/125A versions. 16A connectors are also splash proof and well sealed. 16A splitters of all shapes and sizes are common now, and are now the most common type of lighting connector - other than traditional theatre venues, where 15A is still being specified for dimmer circuits, but they use 16A for hard power alongside.

If you need a standard for your kit, go 16A with adaptors to 13A

EDIT
My latest moving light kit is Powercon powered - so now I'm doing 16A to Powercon convertors too!
 
Thanks for the suggestions, everyone!

Paul, if I may trouble you further for more info. Would the following be good enough for my needs (by the way, it's a Source Four I'll be connecting these to)?

1. 16A to 13A adaptor - http://amzn.to/QCJmWw
2. 16A plug - http://amzn.to/1icHDNM

As for the in-line switch, I haven't seen anything similar in build to the one that came with my 650w — I assume a heavy-duty type is a must?

I've had a dimmer that I've ordered ages ago which I think I was suggested in these boards before, but which I am now no longer sure is suitable. It's a Botex CT 110R (http://bit.ly/1icIPAL). Can someone confirm I can use it with either the fresnel or the source four? Forgive me if this seems like a stupid question; it's because I am entirely new to all this.
 
The Botex dimmer isn't one I'd choose because it's a dimmer module that needs you to connect the input power and output power cables internally and fit appropriate glands, which might be tricky if you don't know what you are doing. It's also available under the Showtec brand. It's not hard to fit a couple of glands, but maybe somebody who is an electrician will do it for you? Price wise, it's good value. They sometimes appear second hand on ebay. The cables you link to are fine. You can buy the bits a bit cheaper at places like www.cpc.co.uk but again, if you're not happy or able to do the wiring, then the amazon ones will do the job.

The benefit of the dimmer you have is that you can stick on whatever connectors you fancy.
 
That I had to google 'glands' might be an indication that I shouldn't go the diy route. Perhaps a future project. Thanks for all your valuable tips, Paul! Appreciate it very much. If there's anything you might later remember to add, please do. I can always do with the extra expert advice.
 
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Michael Carter said:
Tungsten filaments can break pretty easily when bumped while hot, unless it's a really smooth and simple adjustment it's wise to turn 'em off when raising, lowering, moving the whole unit & stand setup.
Click to expand...
Have to disagree here. Most DP''s and gaffers would be irate if a lamp operator did this. Use a gentle touch and they'll be fine. Same thing with gelling them if that's called for while the light is on, although usually that's thought out way in advance. Filaments are actually most fragile when their temperature is changing; a few seconds after the light has been turned on or off is when you want to be very careful.

That being said, a switch is still a necessity simply as a convenience feature. You can still light a movie with fixtures that lack them, but it would be very bothersome and you would have the arcing issue with larger lights.
 
Moseph said:
Have to disagree here. Most DP''s and gaffers would be irate if a lamp operator did this. Use a gentle touch and they'll be fine. Same thing with gelling them if that's called for while the light is on, although usually that's thought out way in advance. Filaments are actually most fragile when their temperature is changing; a few seconds after the light has been turned on or off is when you want to be very careful.
Click to expand...

Yes, be gentle with heads, and you can move them hot. Be extra careful with bulbs with long floppy filaments. In particular, the HPL bulbs in source fours/lekos are long and fragile while hot. I've seen so many fail when apes were knocking them around. Regular smooth panning and tilting will pretty much never couse you a problem though, it's more about lights on stands, thumping the stand down hard when moving it.

Never seen a filament break because of someone putting on a gel.

If you are going to turn a light off temporarily, announce audibly, "Light out" or "repatch"! Then the dp/whoever will know that the light went off on purpose and not to worry.

basic set protocol from a set electrician trained in the film days.
 
Regarding the inline switch, would any common type do (such as this: http://amzn.to/1lBF9w6)? Most of the ones I was able to find are I think rated only up to household lamp use and which I'm guessing is not suitable. And also, what are they exactly called? Is it actually possible to make a homemade version that is close to the one that comes with these lights (i.e., Lowel's - http://bit.ly/QDghdu, Arri's - http://bit.ly/1kYygXk), one that is slim-line or not too heavy?
 
Thje cheap one you linked to will do the job, it's adequately rated so 1.2KW is your maximum load. The only weak link is the cable clamp - and they have a tendency to come loose, but as long as you always keep and eye open for the clamp doing up onto the cable sheath and not the conductors, all should be well.

For things electrical - you should look at sites like www.cpc.co.uk, where you will find many useful bits of kit. 6 amps is sufficient for most common lights - if you have 2K equipment, then it gets a bit trickier, because 2 will NOT run off a 16 or 13A supply. If you intend using 16A connectors, be aware that fully loaded, these really need 2.5mm2 cable, not the thinner 1.5mm2 cable.


On the cable gland front - all they are are plastic devices to allow the cable to enter a metal housing without letting water in, or having sharp edges to cut into the insulation. The Botex dimmer has knock outs - small circular holes that have blanking material in them. You physically knock out the blanking material that's usually just held in with a few small tack welds, or uncut tiny bits of metal. When the knockout has been removed, you have a hole, the gland goes into the hole and when you tighten it up the seals grip and squeeze the cable. They do them in loads of sizes and styles so you just need appropriate ones. Inside the case, you then have the conductors to attach to the terminal blocks. It really isn't hard to do, but you just need somebody to guide you through the first time. Learning to fit different style connectors is a good skill to develop.
 
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