[mythtvnz] OT: Recommended wiring scheme and RJ-45 connectors for Lexcom (Cat7) cable

[Brett Miller]

      James appears to be correct


      Electricity Regulations 1997 (SR 1997/60) (as at 01 October 2008)

extra-low voltage means any voltage normally not exceeding 50 volts a.c. 
or 120 volts ripple-free d.c.

The values might have changed when NZ decided to save money & adopt the 
AS standards.
My old copy of electrical standards dates from 1993 so no help.

An important safety thing to consider with cabling is separation of 
services.
Any conductors in close proximity (50mm in 1993 ?) must have their 
insulation rating raised to the highest voltage present.

The only future proof cabling system is putting lengths of $10 ($4 to 
sparkie) conduit in your walls when you have the chance, especially 
walls that have insulation etc. There is no perfect or best cable system.

Cat5 & 6 are just cheap & easy to terminate.
That is the sum total of all the pro's. But if it works it's good enough.


On 16/02/2010 7:04 p.m., James Gray wrote:
> On Tue, Feb 16, 2010 at 6:51 PM, Jean-Yves Avenard<jyavenard at gmail.com>  wrote:
>    
>> Hi
>>
>> On 16 February 2010 16:34, James Gray<james6.0 at gmail.com>  wrote:
>>      
>>> To install anything with voltage greater than that considered to be
>>> SELV (safe extra low voltage), you must be a registered electrician.
>>> This is basically any time of signal or telecomms cabling (ELV in this
>>> context, means anything lower than 100V AC, or 150V DC. 240V is
>>> actually considered low voltage, compared to a 10,000V power line it
>>> is anyway)
>>>        
>> Hum..
>>
>> Anything below 1000V AC and<  1500V DC is considered low voltage under
>> the AS/NZ cabling rule.
>>
>> Knowing that a standard POTS is 50V DC and up to 90V AC ; that makes
>> it only a sparkie can work on telecomm cable according to your post
>> (don't know what the deal is in NZ)
>>      
> I am a Telecommunications technician. I work in New Zealand. I work
> with telephone installations on a regular basis...
>
> You actually have an interesting point there... Reading further into
> it, Extra Low Voltage is defined as<120V DC or<50V AC... Hence a
> ringing telephone line would be considered low voltage at 90V AC
>
> In practice it's never been a problem. Telecom's PTC documents make
> reference to the fact that many of their own linesmen (well, telecom's
> chorus's transfield's/downer's lines people) are not registered
> electricians, so phone jacks should not be installed within electrical
> installations which require a registered electrician to work on..
>
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