Advice required on DIY mains IEC leads for home cinema kit

[bernardgreen]

I'd just like to know for sure how to do it safely and correctly.

First check the cable you intend to use is designed for 230 volt and is designed for use as a FLEXIBLE cable.

Then contact the manufacturers of the screened cable you intend to use and ask them for their advice as to how to connect their cable to a 230 volt domestic plug. And take note of their PROFESSIONAL advice.

You must NOT take the screen into the 13 amp plug. So you will have to connect the screen to a seperate tail OUTSIDE the plug and then bring that tail into the plug along side the 3 cores (live,neutral and earth). Work out how the cable clamp will secure those 4 wires safely. then consider if two wires of different type will remain secure in the earth pin termination that is designed for a SINGLE wire.

Cable clamps in 13 amp plugs are designed to clamp ONE cable that has an overall sheath over the 2 or 3 individually insulated conductors. They will NOT safely clamp two cables of different sizes.

There are INDUSTRIAL plugs designed to terminate screened cable but these do not fit into domestic 13 amp sockets.

 

[Zambezi]

Just curious, is there is a reason for not taking the screen into the plug?
In my head it would make sense to take the whole lot into the plug and through the cord grip/strain relief then separate everything and insulate the screen, then terminate it all.

The Sky box end:
The regs say a cable supplying a class 2 (no earth, like the Sky box) should have an earth all the way into the appliance (although in your case the cable terminates in a plug rather than the box itself) so on the Fig 8 plug end I would insulate the earth inside the plug and end the screen just outside the plug, then put some heat shrink sleeving on it.

 

[ban-all-sheds]

so on the Fig 8 plug end I would insulate the earth inside the plug and end the screen just outside the plug, then put some heat shrink sleeving on it.

Can you get rewirable 60320-C7s?

And if you could, is there any chance that they'd be able to accommodate a braided 3-core 1.5mm², let alone a 2.5mm²?

They're only rated for 2.5A, so why would anybody make them capable of taking cables rated at 16A or 25A?

 

[mattylad]

If your concerned about EMI attacking your cables, can't you just get some clamp on ferrites & put them at the IEC end?

 

[Zambezi]

http://cgi.ebay.co.uk/FIG8-C7-style...yZ116854QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
C7 rewire-able
The aperture can accept twin core cables of either 18 or 16 AWG. (not too sure what that equates to in English money?)

Quote from another seller:
Many use it with thicker cable by enlarging the entry point and using a cover of heatshrink to act as an effective strain relief.

 

[ban-all-sheds]

The aperture can accept twin core cables

So not 3-core.

And definitely not 3-core with a braided screen.

of either 18 or 16 AWG. (not too sure what that equates to in English money?)

16 = 1.31mm²
18 = 0.823mm²

So 1.5mm² might just squeeze in, but 2.5mm²? No chance.

Interesting that a UK seller is quoting a spec like that - I wonder if these connectors are CE marked?

Quote from another seller:
Many use it with thicker cable by enlarging the entry point and using a cover of heatshrink to act as an effective strain relief.

I wonder what approved testing method that other seller employed to determine that that provided an effective strain relief, and if he got written confirmation from the manufacturer that modifying the product in that way was acceptable and would not invalidate any approvals that the item had.

 

[Zambezi]

BAS if you spend any time on AV/audiophile forums you will soon realise that BS/EN/kite marks/regs etc are the last thing they think of, they are more interested in getting the last little note out of the orchestra etc. A lot of the high end kit is from the States and is imported to the UK, so will not meet UK or European standards.
I had a little giggle earlier, I see somebody is selling consumer units with silver plated busbars etc, why? because some mug will buy it because he thinks it will make his CD sound better

 

[Stevethetiler]

Thanks for the comments.

Ive seen those rewirable IEC C7 plugs (suitable for my sky/blu ray) and seen IEC C13 (i think thats right from memory) too for the TV/SUbwoofer.

They probably arent designed to accept 2.5mm, like you have seen - but like Ban said, i very much doubt if there is one commercially available for that size cable anyway.

Regaarding the earthing of the braiding - and please tell me if im wrong - i thought that it should be earthed in the same pin as the appliance in the wall plug and left unterminated at the appliance end (obviously with the core earth being connected in the IEC 13 plug for the TV?sub?

 

[ban-all-sheds]

audiophile

Don't you mean realityphobe?

A lot of the high end kit is from the States and is imported to the UK, so will not meet UK or European standards.

If it's officially imported, or sold on eBay by business sellers etc then it has to.

 

[Zambezi]

Yes braid is connected to the same pin as the normal earth on the plug end and not connected to anything on the appliance end. Normal earth is connected in plug and appliance end (if it is an IEC with an earth terminal).

 

[Stevethetiler]

Thanks for confirming the braid earthing would be OK.

I know that this is not the intended use for such a cable, and i also know that the benefits in terms of audiophilia are likely to be slim to none.

But, as i said before, it is a hobby, i like making things myself.

Am not one of those idiots who goes out and spends a fortune on exoctic imported components which have been synthetically modified for sale to those with more money than sense!

 

[Zambezi]

Thanks for confirming the braid earthing would be OK.

I know that this is not the intended use for such a cable, and i also know that the benefits in terms of audiophilia are likely to be slim to none.

But, as i said before, it is a hobby, i like making things myself.

Am not one of those idiots who goes out and spends a fortune on exoctic imported components which have been synthetically modified for sale to those with more money than sense!

I am not taking the p*ss out of you Steve, you seem to want to make sensible upgrades to your kit and is understandable, some of the DIY upgrades are cheap and can make a difference. It is the mugs who spend £300 on a power cable that I can't get my head around. At the end of the day as long as you are happy that what you are doing is safe (and at your own risk) and improving your system then I can't see the harm in it. If you start selling things or doing for other people then it is a whole other story. Good luck with it.

 

[Stevethetiler]

Thanks Zambezi,

Am certainly not gonna be selling any home brewed stuff as i dont fancy a stretch behind bars

My main intention here was solely to make sure that the method of wiring the "snake oil" cables was safe (its only gonna sit behind the TV etc so its doubtful that one they are made, they are gonna be moved)

I am fairly competent with the old soldering iron etc etc, so as long as i know that the intended wiring is ok (as long as i ensure insulation etc and correct fit in the plugs maybe by slightly modding the entry/clamps), i feel better about making them myself - instead of giving my hard earned to some **** from an audio store

 

[ban-all-sheds]

Home-refined snake oil may well be cheaper than the bought variety, but it's still snake oil.

You'll be wasting less money than if you went to the **** in the audio store, but you'll still be wasting it.

 

[Stevethetiler]

Possibly so Ban, but at least i'll enjoy wasting it as i will have enjoyed making the snake oil components (must remember to use some of that blu tak stuff too that you recommended in a previous thread.