Rehearsal room/stage electrical safety gear

[Huge Hands]

1 hour ago, TimR said:

 

One band I was in had this scenario. I took the amp home and measured 60volts to earth. It's not static. 

 

It's caused by the 0v of the transformer output not being at Earth potential as it's not grounded via the mains plug.

 

The potential problem is a fault inside the amp causes a fire or the case to become live.

 

An RCD detects an imbalance between the neutral and live. Which you won't get as the 240v side of the transformer is working as expected. 

Hi Tim,

 

I think we are kind of agreeing in different ways.  If the amp was faulty, or causing a PD to its own earth, then yes it would need looking at before it caused itself or the guitarist any damage.  Remember, it is the current that kills, not the voltage, so in some schools of electrical thought, what you read on your meter may have been inside some sort of tolerance (although I doubt it).  Did you get it fixed, or just leave it as was?

 

What I did with the mic cable in my case isolated the guitarist/amp from the PA. so I think, especially as we had a rubber floor on our stage, isolated him enough to stop it hurting his lips or grounding himself in any other way. 

 

I only guessed it was his amp as we didn't have that problem again in the same venue.   However, as I said I vaguely remember him coming the next year with the same amp, so assume he either had it fixed or wasn't faulty either.  

[TimR]

2 minutes ago, Huge Hands said:

2 hours ago, TimR said:

 

One band I was in had this scenario. I took the amp home and measured 60volts to earth. It's not static. 

 

It's caused by the 0v of the transformer output not being at Earth potential as it's not grounded via the mains plug.

 

The potential problem is a fault inside the amp causes a fire or the case to become live.

 

An RCD detects an imbalance between the neutral and live. Which you won't get as the 240v side of the transformer is working as expected. 

Expand  

Hi Tim,

 

I think we are kind of agreeing in different ways.  If the amp was faulty, or causing a PD to its own earth, then yes it would need looking at before it caused itself or the guitarist any damage.  Remember, it is the current that kills, not the voltage, so in some schools of electrical thought, what you read on your meter may have been inside some sort of tolerance (although I doubt it).  Did you get it fixed, or just leave it as was?

 

Yes. The earth wire had been removed from the 13amp plug. I rewired the plug.

 

I also had an incident at a gig where the keys kept cutting out. The keys player realised it was everytime he tapped his foot. Said it would be ok, he'd just keep his foot on the mains plug. I stopped the sound check and insisted on opening it up, and found a very worrying nest of loose wires.

 

Musicians in general are very cavalier with inspecting cables. "If it works, it must be ok."

 

 

 

 

[Huge Hands]

2 minutes ago, TimR said:

Musicians in general are very cavalier with inspecting cables. "If it works, it must be ok."

That is one sentence we can definitely agree on.

 

I do remember working with a pantomime dame who insisted on using his own costumes he had built up over the years.   He had a Christmas tree dress that would be lit up when he walked on stage, then turn off.  I assumed it was some sort of battery thing until half of the lights stopped working and he asked me to take a look at it.  

 

There were fully mains 240V bulbs wrapped around him on 2 circuits.   He would walk out with himself connected to mains, then he would disconnect it by pulling an in-line 2 prong connector apart with one hand and getting the crew to pull the cable back off stage. The two prong plug looked like it was made of bakelite and the socket side could have easily been bridged with a finger when pulling them apart.  When I started going through the dress cabling, I could see where bulb holders had been removed, the wires twisted back together and wrapped (badly) in dried out electrician's tape.   He was a heavy smoker, so a coughing fit and slapping his chest would have probably killed him!   I condemned it there and then and forbid him from using it, which he wasn't very happy about, but I slept better during the run! 

[TimR]

And there we have 4 examples of why PAT Certificates are not just a tick in a box for the insurance. 

 

Venues must see this week in week out.