Re: LF: mains wires

[Scott Tilley <sthed475@telus.net>]

Hi Mal

Something to keep in mind if the product was intentionally designed to be operated on 240VAC here in 120VAC land then it will NOT have a neutral or 'grounded conductor' in code speak. 

240VAC is generated here from either side of a center tapped transformer.  The center tap is the neutral / grounded conductor. 

So for 240VAC here in NA, a neutral is not used but rather two 'hots' of opposite phase.

In a system like this a quite normal way to make a functional control switch is to kill only one leg.  As it is not considered a disconnect switch opening both hots is not required.  The 'code' disconnect switch CAN be the upstream circuit breaker or the cord-set.

So you may ask why the colour coding was still wrong?   Likely the equipment was not UL or CSA certified for NA.  Even then the colour coding is very weakly dealt with on in the the part 1 installation code and not really technically enforceable in equipment.

Assuming the equipment was not designed for EU use they may have not considered this as a potential issue...

73 Scott
VE7TIL
   


On 10/9/2011 6:25 PM, mal hamilton wrote:

Bob

If you look at a Dentron 2500 amplifier on the cct diagram the 230v mains cable,  WHITE  wire goes to the ON/OFF switch on amplifier then primary of HT transformer which to me is HOT and BLACK wire goes directly to the other side of primary winding, NEUTRAL and GREEN to chassis.

In the UK the switch is always in the LIVE (hot) wire and NEUTRAL direct to the appliance except it happens to be a double switch.

 

UK appliance BROWN live, BLUE neutral, plus an earth wire  (3 wire appliance)

mal/g3kev

 

----- Original Message -----

From: riese-k3djc@juno.com

To: rsgb_lf_group@blacksheep.org

Sent: Sunday, October 09, 2011 7:48 PM

Subject: Re: LF: mains wires

what I use to keep track

 

Black is hot white is not

 

Bob K3DJC

 

On Sun, 9 Oct 2011 17:09:09 -0000 "mal hamilton" <g3kevmal@talktalk.net> writes:

LF

I have a USA amplifier with 230v input. The mains wires are BLACK, WHITE, and GREEN

 

The cct diagram shows White as the live wire with amplifier  mains switch in this line, Black goes to the other end directly to transformer primary

and Green to earth.

but

according to USA info the Black wire should be Live and White Neutral.

 

So beware !!!!!!!!!!!!!!

de g3kev

 

 

____________________________________________________________
Get Free Email with Video Mail & Video Chat!