Party Vibe

@`Matt 482369 wrote:

We where using a diesel and she still surged, think in future we are going to have nothing connected when firing it up. Lesson learnt i guess.

Unless the genset is so designed to cope with such treatment its not good practice starting it on load.

Especially not modern digital kit which can have a strong inrush current when starting up (way more than the usual power demand). A old man at a former employer (who really should have known better) blew out the service head fuses by turning on a bench full of AV equipment all at once. Whole fucking place was off supply until SSE came to replace them, also took out the phone system. the losses from that wiped out the profit of this big job for a key client.

Newer gensets especially diesels have fancy electronics to monitor and protect the power quality, but this is all fairly recently. For critical kit even at home/work you shouldn’t even trust what the electric company are sending down the wire until you have checked it against what it is supposed to be. Both the BBC and ITV have been royally hosed this way (400V where only 230V is expected doesn’t do equipment any good at all either).

UPS units are cheap enough even for your home studio though (and whats in the new gensets is often electronics to a UPS minus the batteries)…

I’ve shifted this into its own thread as its a really important subject and seems to be neglected outside Northern Europe.

All AV equipment must have earth/ground of some sort. But it serves two purposes. you have “signal earth” which is a reference point above which anything in the circuit is electricity you want to be there, it may be your music, or a radio signal from a far away foreign land. however all signals transmitted any distance have noise, and special components are used to dump this noise into the ground rails where it does not get received or heard. It is also used (though rarely nowadays) for signalling purposes in telecoms, as telephone lines are usually -50V above earth and so earthing them can be used to show a line is required to make a call.

but there is also protective earth. This is to stop people being electrocuted from equipment where metal is exposed. if this equipment had a wiring fault and a mains wire broke lose, all the metal in it could become alive to 230V! but if the metal is also connected to earth, then this fault current should go to earth and BAM! the fuse will blow or circuit breaker trip. otherwise whoever is holding on to it at the time is sparked instead.

Unfortunately as discussed on here elsewhere there is a conflict due to this being a source of inteference to audio signals, but all equipment with any metal in it connected to the electric mains must have both – its a legal requirement worldwide and folk who have tried to remove protective earth to stop audio problems have been killed.