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DaveK
14-08-2011, 19:25
Hi Guys,
Simple electrical question but as I'm talking about themains current I thought I'd better ask - better red than dead, as they say ;) .
I have been rearranging my set up this afternoon, swapping out my Cyrus pre and power amps and replacing them with a pair of Mini-Ts fed from the Caiman/7520 B-DAC through a valve buffer amp made for me based on the XD10 (I think :scratch:) but with two outputs to feed the two Mini-Ts - big improvement all round so it's a keeper for the moment :) .
Anyway, to cut to the chase, I decided to shorten a very long second hand power lead but when I cut into it I found that the three cores were wrapped in something a little like cling film and that in turn was enveloped in a fine steel woven mesh and then the outer PVC sleeve. So, what should I do with the outer steel mesh? Should it be connected to the earth or left unconnected, and if it should be connected to the earth, at which end, or both. If it's a choice between best SQ or best safety, safety wins every time :) .
Any help appreciated.
Cheers,
Dave

Stratmangler
14-08-2011, 19:29
Piccies ?

Ali Tait
14-08-2011, 19:35
Probably connected to earth in the plug. Make sure it's insulated though, so it can't short to the live connection!

Reid Malenfant
14-08-2011, 19:44
Sounds similar to Mark Grant DSP2.5. You need to connect the screen (outer braid) to Earth at the mains plug only, nowhere else ;)

Stratmangler
14-08-2011, 20:02
Ali/Mark

I concur with you both - just wanted a visual to confirm my suspicions.

Reid Malenfant
14-08-2011, 20:07
Ali/Mark

I concur with you both - just wanted a visual to confirm my suspicions.
That's entirely fair Chris. I should add that the screen definately needs to be insulated where it enters the plug (just as Ali says) so there is no possibility of a short.

You might find that there is a drain wire which contacts the earth screen, this is thin enough to put heatshrink over! Use that, heat shrink it & connect that to the earth in the plug ;)

DaveK
14-08-2011, 20:34
Thanks to all - you have confimed what I suspected but the reminders to insulate the screen to keep it away from the live in the plug was timely. If I suddenly stop posting you'll know I made a mess of it :eek: .

Cheers,
Dave,

The Vinyl Adventure
15-08-2011, 08:09
There is something quite unmistakably 'Dave' about this -
Numptie electrical mains wiring advice please.
Good to have you back here buddy!

DaveK
15-08-2011, 09:04
There is something quite unmistakably 'Dave' about this -
Good to have you back here buddy!

Thanks for that Hamish - I think :scratch: .
Cheers,
Dave.

DSJR
15-08-2011, 09:12
To echo Marks suggestion, check to see if it's been made easy for you regarding a drain wire...

Granny sucking eggs here, but mains is DANGEROUS and fancy mains leads, while having suspect benefits in many cases, ought to be treated with extreme care I think. You know, if it all looks too much, have a word with Mark Grant, who makes a genuinely excellent screened heavy-duty mains cable and doesn't sell it for silly money either - IMO... :)

Covenant
15-08-2011, 16:12
There is something quite unmistakably 'Dave' about this -
Good to have you back here buddy!

I think Dave has been calling himself a numptie for at least 3 years. He should promote himself to semi-numptie.:)