My first tech disaster story.

[Guest pangea]

Hi all - this is my first post, so am looking to make it a good one:

 

I work/help out (seeing as the school has just hired a 'proper' theatre technician, I have been demoted to 'helping' them) at a school's theatre. I spent all day getting ready for an evening concert one day last week - everythign was fine: sound and lighting. The concert began at 19:00.

 

At 15:30, the 'proper' technician looked a little worried. The house lights and a few other lanterns were not responding - and they hadnt tripped. Confused, we set off to the spark room and found that the resistors said 'phase C error': power had been cut all accross the school.

 

I turns out that one of the three fuses/circuits the schools whole electricity ran through had blown - leaving 1/3 of the theatre and rest of the school in darkness. At 16:00 we get told that the electricity is about to go off completely - in roughly 2 minutes.

 

Not fun, seeing as half the theatre lights, all the audio equipment and projection stuff is turned on, and there are rehearsals still going on inside the theatre.

 

So here I am, running round like a right wally, switching everything off at breakneck speed. After killing all the (remaining) lights, I head down to the spark room to switch off the resistors themselves - something ive never had to do before. How? Where's the oh so simple 'off' button?

 

After a very very quick conversation via mobile with someone who actually knew what they were doing, I located the fuse-box-like-thing for the resistors and killed all power.

 

It turned out that one of the schools three 400Amp fuses had blown, due to a drill being switched on (!) over in DT... One of the maintenance guys had to drive over to a town somewhere I can only describe as far-far away.

 

At 18:25 he got back.

At 18:35 everything was ready for use and I had the pleasure of booting everything back up again: whilst the audience was waiting outside, totally unaware of how close we had been to cancelling.

 

PJB

[Rob_Beech]

Welcome to the Blueroom, and welcome to the industry :P

 

No doubt you'll have many more close calls, the fact you knew what you was doing, and when you didn't you asked for advice rather than just trying things is a good sign.

 

Rob

[JimWebber]

Welcome to the Blue Room!

 

Good story, but, you will soon discover in our wonderful world, 25 minutes is a luxury...

 

PS I'd also check your terminology, what do you mean by "Resistors"? Most people on here will be thinking of electronic components...

 

Jim

 

Edit - AS Rob says, don't EVER feel ashamed to ask for advice if you do not know what you are doing! Well Done!

 

J

[sonic]

People who don't ask for advice are the most irritating people - a guy I used to work with at Stage Electrics had a very good saying to anyone trying to do everything them selves:

 

"There's no heroes in this game!"

 

So true, there is nothing more annoying that when some jumped up prat turns up and thinks they know everything (I used to be that guy - then I grew up!)

 

What exactly do you mean by resistors? I'm assuming you were meaning fuses?

[Pete]

What exactly do you mean by resistors? I'm assuming you were meaning fuses?

 

See I assumed dimmers

[paulears]

Well, assuming that the date has nothing to do with this first post - somebody plugging in a drill that takes out multiple 400A fuses means calling in the A team - these sound like main intake fuses, and considering all the other protection going on between them and the users, should never blow. There is something seriously dodgy going on here, beyond - far beyond the kind of thing anyone - technician, or helper should be interfering with. Any fuse that needs a spanner needs a 'real' sparks to heave on it!

 

I'm assuming this is a joke - if it isn't - it is very, very frightening for a building full of kids!

[Ynot]

I'm assuming this is a joke - if it isn't - it is very, very frightening for a building full of kids!

Hmmmm....

Me too - I also find it disturbing that the OP is a little derogatory about the 'proper' technician, especially considering that tech is likely an adult whilst the OP still a student.

It matters not that the OP may have a couple of years 'experience' with the geography of the school premises - the (presumably) new guy being dumped in the brown stuff early in a job placement without in theory having gotten to know the lie of the land is unfortunate. To cast aspersions as such in these circumstances is maybe not the best thing to do!! :P

[sonic]

I'm assuming this is a joke - if it isn't - it is very, very frightening for a building full of kids!

This doesn't seem like a joke - which is worrying... but having said that - hopefully the "maintenance guy" should see a problem and seek to solve it.

 

To cast aspersions as such in these circumstances is maybe not the best thing to do!! :P

Sadly, having worked in a school as the new technician - the kids were very cautious of me to begin with... they saw me as a threat. They seemed to have difficulty understanding the reasons why I would ask them not to do something - even if I tried to explain the safety aspects of my reasoning they still thought I was doing everything in my power to stop them having fun - which wasn't true.

 

It is unfortunate for the poor new guy! I luckily never had any issues that serious while I was there. Having said that - we did have one incident which still hasn't been solved... for some reason the LD90 kept tripping out for no apparent reason?

 

I took a look at it but didn't have much knowledge of the LD90, the school electrician had a look and he couldn't figure it out so we called in a Stage Electrics engineer to take a look who couldn't work it out - so he called his boss to come have a look... still no idea! So we ended up just leaving it all safe and resigned ourself to the fact that one string of houselights didn't work.

 

One of the channels seemed to be shorting - but having tested the circuit we couldn't find any fault on the line, so we swapped out various different PCB's in the LD90... still didn't work... after roughly 2 weeks - we gave up!

 

Sorry if that was slightly off topic but it seemed a fitting place to explain it!

[cedd]

Main 400A fuse reads to me like the electricity authority incomer! If you've popped that, you've done rather well!

 

Driving across town to pick up a replacement sounds dodgy to me!!!!!

 

I read resistors as dimmers too!

 

As it happens, this happened to me in a church. Main fuse had been bashed by a builder and was quite badly mangled without anybody knowing about it. I had the lighting rig and sound system on when the lighting rig started flickering. Walked into the electrical cupboard to find the heating contactor banging in and out rather violently. Plus lots and lots of smoke pouring out. Couldn't pull the main fuse cause it was too mangled so hit the fire alarm, shut off all the loading and as the instructions on fireworks say "retreat to safe distance".

Had to shut the whole street off, the fuse was that mashed and impossible to remove!

[Ynot]

Main 400A fuse reads to me like the electricity authority incomer! If you've popped that, you've done rather well!

True - must've been a pretty hefty drill to have popped a 400A fuse!!! And a VERY faulty one, at that!!

:P

[dbuckley]

Not so; these fuses are in place for years, and they become weaker. The drill is just the last straw. And when the incomper fuses go, it takes hours to get them repaired.

 

This sounds bad at a school, but can you image what happens at a City of London merchant bank takes out a 600A fuse, and then does it again to another one a couple of days later....

[Guest pangea]

hiya guys....thanx for comments.

 

erm..well I had to switch off what looked like a master fuse (inside a fuse box)

 

this turned off the DMX (?? I think thats the right name)....which I was always told were the resistors....but you ppl know a hell of a lot more than me about this stuff so any suggestions would be appreciated for future reference.

 

** laughs out loud **....yeh, we do have some rather large bits n pieces up in the DT department - probably some sort of metal work drill.....dunno - its just what I was told.

 

whoa...paulears...

 

sorry I just read your reply.

 

nope, sorry not a joke. believe me I had fun running around shutting stuff down and throwing people out of the theatre (people tend to listen to you when your running around, carrying a selection of screw drivers to get to the fuse box.)

 

ps: Ynot...the real technician also had not a clue what was going on....this is their first tech job and they too are still waiting for proper training from a pro. sorry if I sounded condescending.

[Just Some Bloke]

any suggestions would be appreciated for future reference.

 

OK. I hope you won't mind me mentioning that here on the Blue Room we often find ourselves talking about complicated and precise subjects. For that reason and others we like posts to be written in a precise way and not use txtspk.

 

E.g. thanx, ppl etc. - in our business PPL stands for Phonographic Performance License.

 

We also like capital letters. I know they are going out of fashion but in all formal writing they are still used, and we like them too.

 

On to technical stuff, DMX stands for digital multiplex and is the "language" that the lighting board uses to talk to the dimmers. The dimmers are the equipment that provide power to the lanterns to make them work. I suspect these are what you were calling resistors. I also suspect that what you refer to as a master fuse is what we would call a "breaker" as it breaks the power from that point onwards.

 

I hope all of that helps. I also hope you continue to enjoy helping with the theatre and joining in with the Blue Room.

 

See you around.

[Tomo]

Not to mention that there are two possible 'master fuses':

 

1) The Main Breaker - this is an MCB or RCBO that will disconnect the equpiment if too much current flows. (Or in the case of RCBO, if there is a current imbalance - ie some current isn't coming back and is maybe going through you!)

2) The Main Disconnect - this is a whacking great big switch that can be manually closed and opened to turn the equipment on and off.

 

We all live and learn!

 

And remember - the ONLY stupid question is the one you didn't ask!

[Bryson]

I think it's worth remembering that in many older buildings the Main Fuse is exactly that - a fuse. (A big, coke-can sized one, usually!) MCBs and RCBOs are not universal, much as that would be nice!