Brian

All rectification and regulation is done in the desk. The 48v phantom supply is made with a bit of capacitively coupled voltage doubling.

it has arrived with a piece of paper with chinese instructions and broken english translation explaining the DMX channels but no mention of gas

So, no clear instructions. Meaning its CE mark is invalid. Meaning that if you imported it directly you are about to break the law (and invalidate your insurance). Or if you bought it from an EU based organisation then they are breaking the law.

 

Apart from breaking the rules on CE marking you might want to look at what sections of the HSWA via PUWER has been broken.

 

There's a very good reason such units are cheap.

Could using non-snubber triacs in the past have damaged another part of the dimmer maybe?

Very unlikely. And if it did not in a way that would cause the problems you are seeing.

 

What is the PSC?

Prospective Shortcircuit Current

 

It's a figure, usually in the 1000A plus range, which indicates how much current your mains supply can deliver when it's short circuited.

 

If you're at the end of a long piece of cable the resistance of that cable will reduce the PSC. If you're right next door to a substation then it'll be higher.

 

If you have site electricians, or can arrange it next time an electrician is on site, it's a fairly easy measurement to take. Measured at the connection point for the dimmers it might give you an idea of what is going on.

 

Do you have these dimmers installed on any sites where they don't exhibit the problem?

Have you used the 610's?

 

...most of our venues use Betapacks ... I just dont understand why im having to put such massive triacs in these packs ...

 

I've not come across the 610s. I've used plenty of others including loads of betapacks without problems. It does seem very odd.

Odd, I don't think I have ever lost a triac in a dimmer rack.

I've seen fault current figures for a PAR64 of around 140 Amps; limited only by the impedance of the mains supply.

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Electrics Relevant To Backstage

 

Institution of Electrical Engineers Code of Practice for In-Service Inspection and Testing of Electrical Equipment

 

http://images-eu.amazon.com/images/P/0863418333.01.MZZZZZZZ.jpg

 

...code of practice for the in-service inspection and testing of electrical equipment. It includes advice on compliance with health and safety legislation. The text specifies the frequency and scope of inspections and testing in different environments.

 

Institution of Electrical Engineers Guidance Note 3 to IEE Wiring Regulations BS7671: Inspection and Testing

http://images-eu.amazon.com/images/P/0852969910.01.MZZZZZZZ.jpg

A guide to electrical inspection and testing.

 

Institution of Electrical Engineers Electrical Maintenance (Code of Practice)

http://images-eu.amazon.com/images/P/0852967691.01.MZZZZZZZ.jpg

...provides guidance on the legal responsibilities as well as full technical support for technicians and electricians, including inspection and test requirements.

This FAQ is now replicated, extended and superseded by the one on the Blue Room Wiki, here.

 

The Blue Room Sound FAQ

 

 

Looking for Secondhand Audio Equipment?

 

1. You've tried Google and it's friends? No, well stick 'secondhand audio equipment' into a search engine and prepare to be amazed at how many results you get. Narrow it down by adding your country, region or nearest large town.

 

2. e-bay is full of the stuff.

 

3. Failing the above, here is a list of a few regular dealers in professional audio equipment, it's by no means complete and biased towards the UK...

 

10 out of 10

AC Lighting

Adlib

APR Audio

Bob Kelly

Bonza

Entec

Intasound

Larking

LMC Audio

Orbital Sound

SSE

Stage Electrics

Tega

Used Lighting

Used StageSound

 

...if you know of any more who regularly have equipment for sale then let us know.

 

 

Looking for the Pin Out for a Connector?

 

Tom Baldwin's Site

 

 

Looking for a Sound Hire Company?

 

Visit our Friends at Stagelink

 

 

Computer Based Playback anyone?

See Computer Based Playback.

 

Where can I get sound effects?

Users should check any relevant licensing they need is in place if planning to use any effect in their shows.

See Sound Effects.

 

Microphones

 

Shure's Theatre Guide (1.5Mb PDF File)

Loads of other Stuff on the Shure Website

 

 

Radiomic Licensing

 

JFMG who deal with licensing radio mics

This post summarises the situation as March 2006.

 

Minidisc

 

Minidisc recorders are getting rarer and rarer. A good unit which is still available is the Tascam MD-350.

 

 

Recommended Reading

 

Click here to go to the Recommended Reading topic.

 

 

What sound equipment should I buy / hire for my school / college / church / village hall / other small venue or system?

 

A number of ideas and opinions on this subject can be found in the following threads...

 

speakers and amps

PA Advice

Radio Mics?

Amps And Speakers, good quality second hand stuff

Looking For A New Desk

Small desk, 4-5 channels, **cheap**, help?

New Kit - Suggestions please, Merged

Budget sound, Good sound on a small budget

Suspending/Flying Mics

New mixer advice, £200 - £250

sound hire, education

Live PA Mixing Desks?, Freind Starting out needs Advice

PA Mxing Desk, Serious advice needed..

A New PA, What to go for?

Radio mic advice

Best value dynamic wired mics?

Recording A Choir, What kit do I need?

PA system for school

Live Band sound, in a 200 capacity hall

New Pa advice needed, What do you think we need?

150w-200w small speakers?

Radio Mics, Revisited

Advice needed, FA101 and other equipment...

Microphone help

mixer advice, what should I buy?

Micing for school play, just to check again

Sound for a band, HELP

Active speakers for a small school, Suggestions please?

£4000 What to buy?, A new PA for my School

Buying small PA System

12-16 channel mixer, Budget £400-£500 for a church

tiny mixers

Sports Halls

Best value radio mic kit, What to buy?!

Small mixer for connection to Mac, Music facility

PA system for Contemporary church

How much power?

digital snake for house of worship help

Choice of general cover mics, Overhead/Boundry/Rifles?

All in one PA units, Wireless mic, input for cd

UHF radio mics…, Which system for around £230 ex vat?

Having Your Own Gear

Church PA Equipment, What to buy to expand with 1.2k

Small pa for solo musician

Looking for reliable CD- Deck, for school

Computerised Sound, What can we get for £800?

Digital Sound desk for school, Some advice please

Help with improving venue acoustics, Damping reflections

Small Monitors

what mixing desk?

Seeking advice: interesting charity sound installation

70W - 120W Amplifiers

Recommendations for installation and accoustics, Church redevelopment project will involve some serious work

Mixing desk, which one?

 

 

 

If you have any suggestions for more useful information then please PM me.

Or just one or two 650W Minuette profiles, spotted and irised down. About all they're good for, really.

The problem with irising (is that a real verb?) down a spot is that you are throwing away light. Close the iris to half the open diameter and you waste 75% of the light so you may as well use a 150W lamp the right size.

I've just made myself some specials for mirror balls using PAR56 marine searchlights, 12 volt 100W very narrow beam lamp. I bought some cheap PAR56 cans and bolted them to the top of a metal box containing a 12v transformer. Mains enters the box on a standard 15A plug.

ELCB = Earth Leakage Circuit Breaker. This term should not now be used as strictly speaking it refers to the 'old' way of detecting earth currents. The earth wire of the circuits being protected used to run back to the ELCB where it would feed through a senstive coil, the other side of which connected to the real brown earth. Any fault current flowed through the coil causing it to trip the mains. The problem was that the earth circuit was not continuous (it went through the ELCB) and it had a high resistance, caused by the coil.

 

RCD = Residual Current Device. Works by putting the Live(s) and Neutral through a coil which detects any imbalance in the current flowing out (live) and back (neutral). If there is a difference then that current must be going somewhere where it shouldn't so it trips. These are better as the earth is a nice low resistance continuous circuit.

 

MCB = Minature Circuit Breaker. An overcurrent protection device.

 

RCBO = RCD and MCB in the same lump.

 

RCCB = NRA (Not a Real Acronym)

 

the 30ma RCD tripped

 

An RCD is protecting against earth leakage - so will only trip when you have an earth fault

 

I wonder if what he has is an RCBO - a combined MCB (circuit breaker) and RCD?

 

A 13A Plug Fuse (BS1362) will carry 13A indefinitely

A point which many people overlook. On the other hand, IIRC, a US 13A fuse is rated to blow at 13A.

You need to make yourself an adaptor which lets you put the clamp around just the live wire. Basically a short 13A plug to 13A socket lead but wired in single core cables. BUT make sure you use double insulated cables of the correct size. If you don't know how to do it, get an electrician to do it for you.