Re-use or start again?

[Hockeybod]

The lights in our school hall are awaiting PAT testing, and when I took them all down it was clear that it's a motley collection and some are very old. We'd like to go down the LED route but I've no idea whether to budget for ripping everything out and starting over or trying to re-use some of the existing installation.

We have a Jester desk which won't run LEDs so that has to go, but it does mean we have DMX cabling in place

There are two banks of Betapack3 dimmers hard wired to the lighting rails with their 15A output sockets. Are there any LEDs that will run from those?

How much of the existing installation might be re-used? I understand a combination of LED and tungsten is possible, assuming some of our current lights pass PAT!

[Davidmk]

We run a mixture at my usual venue (The Stables, Milton Keynes - tech spec here). It works pretty well but we are a music venue, it would be trickier for theatre because white on LEDs, discharge lamps and tungsten is so different.

Initially you probably want to replace any floods or parcans with LED. IMHO this will get you the most bang for your bucks. Replace Fresnels as well if you have the budget. Leave focus spots and/or discharge fixtures until you have to or have the funds to replace the whole rig.

However, that is just a first reaction - you could replace the focus spots first but I'd suggest you need to do all of them at the same time whether they pass PAT or not so that they all have the same colour white. You will probably need to replace these one for one.

Floods, parcans and Fresnels you can replace some and keep some and may not need so many LEDs as you currently have tungsten (because LEDs can be different colours in each cue).

Do not, under any circumstances connect any DMX controlled fixture to a dimmer, there will probably be a loud pop from the dimmer and it will stop working. There may be LED fixtures designed to be connected to and dimmed by dimmers but I'd be surprised if they also have a DMX input.

You will need to run raw power and DMX to all the DMX controlled fixtures and, given that you are working in a school, you'd be very wise to use different plugs and sockets for the raw power e.g. blue CEE 16A, Powercon, Powercon True or even C13/C14. Preferably not 13A though - there's always the risk of a fuse blowing up in the rig somewhere although you may be able to use 13A sockets for your supply.  LEDs don't use anywhere near as much current as tungsten or discharge so one 13A socket will run quite a few LED pars but do keep an eye on that, don't overload the socket or the ring main. Also don't mix your phases - use the same phase as any dimmer outlets on the same bar.

LEDs do use more DMX channels though so you may find you need a second universe and have to run another connection from your desk position to your rig as well as running DMX around the rig itself.

[Hockeybod]

Thanks, I know the Stables well living in Princes Risborough and having been there a few times.

I'm coming to the conclusion that we might be better staying with what we have - what are we gaining from switching to LED apart from easy colour change? There's plenty of used tungsten lighting out there if some of ours don't survive PAT, and we already have more lights than we really need or use. What we really need is expertise, not more kit!

I don't suppose you live this side of MK...?

[kgallen]

A conventional fixture is a very simple electrical device. If they ‘fail PAT’ then the fix to make them ‘pass PAT’ should be very straightforward. If they fail earth bond replace the earth bonding inside the lantern and the main flex with 180 C silicone. If they fail insulation then just the main flex should do it.

I think you came here from BlueRoom. If so I’m glad to hear you are going to keep you conventionals (for now at least!).

[Hockeybod]

Agreed, 45 years ago I rewired all the lights for an am-dram group that my parents belonged to, but I'm a bit busier these days!

[Davidmk]

2 hours ago, kgallen said:

I’m glad to hear you are going to keep you conventionals

Well so am I, sort of. There's a lot to be said for keeping old kit going. Conventionals are simple and in a school, or any other environment where the user's main skills are in other directions, simplicity can be key. They can, generally, be fixed and they are pretty robust so the fixes should be easy and cheap. We've got 4 SILs , rescued from a skip more than a decade ago and all our conventionals are at least 22 years old. I trained as a teacher and I didn't find a lot of hands on tech knowledge among my fellow students. Especially not in my class of Drama mains. Guess who got the job of building sets and lighting the annual assessment productions.

However the move to LED, while slow and resisted in some quarters, is inexorable and this will contract the market for spares and lamps making them more expensive and harder to source so the day will come when it is no longer possible to resist. 

3 hours ago, Hockeybod said:

what are we gaining from switching to LED apart from easy colour change?

Well, lower electricity bills for a start but as the stage lighting is probably a small part of the schools power usage this is probably not a deciding factor. Not sure we can claim LEDs are better for the planet - fair enough they use less electricity and produce less heat in use but I have no idea what damage their manufacture does to the environment.

LEDs are (IMHO) way superior to gels in parcans. Not only can you mix them on the fly and tweak them when the director says they are too cold, hot, yellow or whatever but the transition from one colour to another is so much more controllable - it can be instant (no waiting a second or so for one set of cans to cool down and another to heat up) or it can be timed over a whole scene (20 minute sunsets anyone?) and go through all the colours in between. Plus you don't need a cabinet full of gels or order them in advance (and be stuck with what you ordered) and there's no climbing into the rig to re-lamp and hardly any chance of a lamp going pop just as the overture finishes. You need less of them as well - if it takes 6 cans to light your set for daylight it will need another 6 to light it for moonlight but with LEDs you just use the same 6 for both.

Then there is the educational aspect. Somewhere in your school there may be kids who will be part of the next generation of amateur and/or professional designers & techs. They should be getting some exposure to the 21st century, not go out into the world only knowing about stuff that was around when I was a lad half way through the 20th century.

On balance, I would say that, if you can get the budget, you should start your transition into the 20th century.

[iank99]

11 hours ago, Hockeybod said:

I'm coming to the conclusion that we might be better staying with what we have - what are we gaining from switching to LED apart from easy colour change? There's plenty of used tungsten lighting out there if some of ours don't survive PAT, and we already have more lights than we really need or use. What we really need is expertise, not more kit!

From experience, the actual fact is that most "vintage" lanterns will survive PAT but not the person doing the test unless they're a theatre specialist - the normal PAT person will throw a wobbler at the old round pin plugs, no fuses in the plugs, no decent earth on the patch cords & be unable to properly test a theatre lantern.  The only likely pitfall will be if you have old Strand Patt lanterns is that P28 lampholders are getting difficult to acquire so keeping them going is tough - not so much the newer bi post lamps.

David is correct - you should be considering some LED lighting but the cost of swapping the whole rig over isn't going to work if the school have to fund it, the kit might be cheap (do NOT buy the cheapest - its false economy) but the infrastructure/power changes are not - a rough ball park would be around £250 per fixture when you cost i the fixture, an electrician and so on - that's using the existing wiring. It would make some sense to buy a handful of LED's to use for flood lighting to replace any conventional floods but replacement LED profiles aren't cheap & you always need a profile sooner or later.

The desk replacement is going to be an issue too - you'll want something a 'naiive' user can operate without notice & this counts against PC based software so you're looking at something like FLX S but ideally the FLX because it gives more faders to control lights rather than just scenes - however, not cheap even with a decent discount.

As you seem to be coming round to the idea of cleaning the existing kit - have the desk checked & serviced (it will likely need a new battery and perhaps at least one fader replacing) and check the dimmers are OK.  Take a note of the numbers on their displays - the DMX address and do a factory reset on each then reset the addresses is all that Beta 3's generally need in a school installation.

I can service the desk, David & Kevin can vouch for the quality of my work & I'm sure they could recommend a decent supplier of spare lamps, replacement plugs and so on to service the lantern stock. It will also be cheaper in the short/medium term whilst the school considers replacement  - get some external advice & a couple of quotes from reliable suppliers for this - they WILL appreciate the schools situation.

[Hockeybod]

Funny you should say that - I replaced the main fader and CMOS battery (since I was in there anyway) just a fortnight ago. Unfortunately I managed to accidently change the DIP switch settings which caused me some anguish, but Zero88 nailed the problem straight away.

[Davidmk]

As always, Ian is spot on. Heartily endorse his work