How much electrical knowledge do you need?

[Jerome]

I've been having a discussion with a friend and I was talking about a recent job I have just done and I was set about installing the electrics (with others) for a large corporate event. As students we were discussing the need to understand electrics in total I.e calculations etc. I made the point that as tekkies we needed to know as much about the electrics running through our lights, sound etc just incase on a job one day we had to fix them if they had a big electrical fault. Plus how do you know its an electrical fault? He said that that is what a sparkys job is. Now is that true? Do we need to understand our electrical components and if so to what degree? How much electrical knowledge do we need? I know the answer is as much as you want to teach yourself but how important is it to understand electrics for our careers?

 

Its hard to see where our job ends and there job starts.

 

Jerome

[adamharman]

The question is where is the line between what you need to know and what you want to know.

 

For personal interest, learn as much as you want.

For work, regardless of what you actually know, you only know as much as you are qualified and insured to do.

 

If your job is cable bashing and plugging things in where you're told to, you don't need to know very much at all.

If you're expected to design a large temporary install, then you obviously need to know what's what and what the regs are.

 

Anything to do with the fixed wiring in the venue, and anything beyond stuff that plugs together is best left to the sparkys.

[adam2]

A reasonable knowledge of electricity is to be recomended and will make your work easier, and possibly also safer.

Anything unduly involved, or traceing all but the simplest faults should be left to an electrician.

 

IMHO the following tasks could be done by a theatre or similar technician with basic electrical knowledge. Requiring a qaulified electrician would by going too far, in my view.

Replacing lamps in lanterns

Replacing a damaged flex on a lantern with new similar.

Fitting or replacing plugs

Making extension leads

Replacing fuses in dimmer racks or other equipment

Determining the maximum number/wattage of lights that can be used on a given supply.

Carry out PAT testing useing a semi-automatic machine.

 

I am not suggesting that these tasks are trivial or that they should be done without any training/instruction/experience, but I believe that they can be done safely by someone without formal qaulification.

 

Anyone under 16, or perhaps 18 should be supervised by an experienced person.

 

A good knowledge of basic electrical theory and practice is very useful indeed, and can avoid needless expense.

At the very least, one should know the following, the current rating of the common smaller types of flex, the current rating of the more common types of connector ( and roughly how many watts this at 230/240 volts), what does an RCD protect against?, what does an MCB protect against?, what is the cause and the result of excessive voltage drop etc.

 

If dimmers must be plugged into 13 amp sockets, which is not ideal, it would be useful to know which sockets are on which circuits, and what the rating of the circuit is, and what else is on the same circuit.

 

Anyone involved in theatre lighting should know the location of the mains intake, and the location of any main fuses or circuit breakers, even if not competant to work on such equipment, you should know its location! Dont assume that a call out electrician knows your building!

Also find out where the keys to such places are kept, even if not authorised to obtain them.

 

(I remember as an electrician being called to "no power to dimmers" in a school theatre, replacing a blown 60 amp fuse took all day, no one knew where the main switchgear was, when I found it by following the cables, no one knew who had the keys, headteacher? caretaker? school secretary?maintenance contractor?. The key never was found, I had to force the door! The fuse was found to be an unusual type, 2 hour trip to find some. total bill was well over £500, think how much money they could have saved by knowing where the switchgear was, by having the key available, and by keeping spare fuses on site, or even better by limiting the load to 60 amps and not blowing the fuse in the first place!)

[JDP]

Jerome,

 

When you say 'installing' how do you mean? I highly doubt you were installing more running cables and plugging them in, correct?

 

My job is effectively as a touring electrician, but I will come back to that later - perhaps, Jerome you could answer my question first?

[berry120]

As for what you should and shouldn't do, my take on it's simple - stick to what you're competent at, and only what you know you can carry out safely. If you're not sure, leave it to someone else.

 

As for what you should be competent at, yeah there's the basics like knowing how not to overload dimmers and that sort of thing that I believe everyone should know. But that I believe is part of the knowledge to use equipment properly and safely - the same with changing bulbs and replacing damaged flex, that's learning how to look after your kit (if you're a lampie!) But outside of that, personally I think it's all down to interest. That's not saying it's not useful to learn, it sure is, but I think it's a good option to have to increase your knowledge rather than one you need to do the job properly.

[Bobbsy]

Let me come at this from a slightly different direction and say that, even if not qualified or knowledgeable enough to be an electrician yourself, as you progress in the industry you will soon reach a level where you need to be able to have an intelligent conversation with an electrician.

 

You certainly need to be able to specify, in the proper terms, your power requirements and also be ready to answer questions like "could you use XYZ instead?". In my experience you need to be able to understand and work with the difference between kVA and Watts/Kilowatts, have a discussion about Power Factor, know the issues involved in working with 3 phase vs. single phase and so on. Even if you don't have to design and install these systems, you WILL have to discuss them with whoever is doing the install for you. In my experience, you're often working with electricians or electrical consultants who know industrial and domestic stuff but who have never worked in theatre or broadcasting. You have to know your stuff well enough to know when to "push". Earthing schemes for sound and video systems are one example of this I can think of straight away.

 

That said, you also have to be careful of the "a little knowledge is a dangerous thing" trap. Just because you can discuss things with a qualified electrician doesn't make you one!

 

Bob

[dbuckley]

Took the words out of my mouth, Bob.

 

At any level of theatre lighting, there are certain basics you need to understand, mainly to stop people laughing at you, but also so you can plug stuff together with good confidence it will work and be safe.

 

The first things you need to know are about loadings, so you can determine how many lamps on a dimmer circuit, and what cables to use etc. Note that although a theatre spark will know a 2K frez from a pinspot from a Martin Atomic strobe, a "normal" electrician wont, and in these circumstances you need to be able to fill in the gaps, in terms of what you need, but in his language.

[Jivemaster]

On a JOB, understand what you are asked to do, and do it well. That way you will get asked back and paid again! Dont stray into areas where you are not wanted trying to do repairs you may likely not be insured to do tasks like that and may not be the best person to do the job. If you have to use a tool think; "am I competent"

 

In the classroom learn about things! Ask careful questions, Review what you have actually been engaged for.

 

Use your tutors to explain what you have done in work and why, that way you learn fron the job and can make progress

[Jerome]

Hi guys and thanks for the repiles its hepled a lot.

 

Seems to me there's a difference between the two just because of how our industry works.

 

JDP- when I said I was "installing" I meant that I was just plugging in appropriate cables etc. Not rewiring a load of racks for example.

 

In terms of my competence level I can PAT test things, fix lights etc, set up a three phase system to a plan however its making the plans and things that would confuse me and understanding how it works...safely. I'm intrueged at what bobbsy said as someday I may have to have these conversations with sparky's and it's that knowledge that is proberbly missing at the moment as I don't understand electrics to that degree.

 

Are there any appropriate books anyone could suggest on stage electrics? I'ts ok going down the library and searching or googleing it but if one have you has a book that has been like a bible to you then it's bound to be worth my while buying it.

 

On another comment, my tutors do explain things to me but only on a certain level as they themselves aren't sparkys however they know a lot more than me but the time it would take them to explain to me aswell as them teaching me all the other areas on my course they would be there forever. I think it's all the calculations and stuff that confuses me. I'm only on a BTEC at the minute but I'de study it off my own back for my own good.

 

Hope to hear from you

thanks to all again

 

Jerome <_<

[Jerome]

anyone? :** laughs out loud **:

[Mexi]

From the other point of view, how much do sparkies understand about Theatre electrics? How often do you see the wrong types of outlets, in the wrong positions and panels obstructing places to put scenery?

 

In the ideal world everybody would talk (and listen) to everybody else. Maybe a casual, friendly conversation with installation peeps would benefit you both whilst work is going on, without standing on toes.

[JDP]

Hi Jerome,

 

Sorry for the delay, been working and I don't get summer holidays like some!

 

As I suspected, you were plugging things in and running cables. So, to be honest, doing jobs like that, I would expect Gallowglass or a local crew to do that job.

 

Lighting technicians (ie more intelligent people to rig and plug in) I would expect to have a rough knowledge in electrical bits. I would expect them to know about plugging in lanterns, knowing the different between hot power, and to know about basic electrical things. However, I would expect the dimmer man to have already done all calculations and the lighting techs to follow the plan, unless they spot something totally wrong.

 

The dimmer man (thats me) I would expect to have full electrical knowledge, both nationally and internationally. The dimmer man does all calculations, works out electrically how the system is going to go together and will write up all relevant information to give out to the pluggeruppers.

 

Your comments about a 3 phase plan confuse me, you don't set up a three phase system. Three phase is what comes out of the 'wall' and you plug in your racks and distro from there...

 

I can't really think about books. You need to know basics like be able to calculate the wattage of a unit, how many amps it will pull etc. Those are essential. Its also useful to know how to do electrical calculations on 110V, as rock n roll companies still very much use 110V pars, and when working in the US and 110V countries its good to know. Additional items, things like series and parallel splitting, theres no harm in learning your way round Avo FD and Avo Art racks, especially on the patch, and knowing when and when no to use shorting plugs is more than essential to avoid blowing things up!!

[Bobbsy]

JDP's post is probably accurate for the touring/rock show part of the industry but it's worth noting that the OP specifically mentioned a corporate event and also that he's just finishing a course which seems to have a reasonable emphasis on theatre-style performances. It's worth saying that, except for the "top of the pile", there tends to be a lot more need for "multiskilling" in the theatre world.

 

Bob

[themadhippy]

Your comments about a 3 phase plan confuse me, you don't set up a three phase system. Three phase is what comes out of the 'wall' and you plug in your racks and distro from there

If you don't set 3 phase systems how do you know if your phases are balanced and wot your neutral current is.Also is it not a requirement of the regs to have suitable documentation showing the layout of the electrical distribution systems?

[JDP]

Sorry, probably mis understood what Jermone meant. I thought he was of the opinion that you 'made' three phase.

 

I wasn't aware that it was a requirement to produce these documents. I do produce these documents for ease of other people to follow and fault find.