4.0mm or 2.5mm SWA


Postby holdbacktheriver » Thu Oct 11, 2007 7:30 pm

Hi,

Looking for a bit of a straw poll and opinion on this matter.

What I want to do is place 2 outside sockets at the front of my house that can be switched off via a switch when not required, so they won't be permanetly live.

The socket will be an 13A IP55 rated 2g socket. The biggest load I suspect this will carry is my Karcher when I clean the car. I think they come in at about 2kW.

The sockets will be fed from the 2nd MK Sentry CU in my garage the following way:

Mains fed 30mA RCD > 16A MCB > to a 13A fused FCU Neon Switch to the IP55 2g socket. This allows me about 2990Watt load. Plenty.

Now heres the crux. the distance from the switch to the socket will be about 26 metres. The garage is detached at the back of the house.

I realise about V drop over distance but can't work if to use 2.5mm or 4.mm SWA?? I'm swayed to go with the 4.0mm just to future proof my self in case I want to use a bigger load in future.

Any advice would be helpful.
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Postby BLAKEY1963 » Thu Oct 11, 2007 10:54 pm

[quote="holdbacktheriver"]Hi,

Looking for a bit of a straw poll and opinion on this matter.

What I want to do is place 2 outside sockets at the front of my house that can be switched off via a switch when not required, so they won't be permanetly live.

The socket will be an 13A IP55 rated 2g socket. The biggest load I suspect this will carry is my Karcher when I clean the car. I think they come in at about 2kW.

The sockets will be fed from the 2nd MK Sentry CU in my garage the following way:

Mains fed 30mA RCD > 16A MCB > to a 13A fused FCU Neon Switch to the IP55 2g socket. This allows me about 2990Watt load. Plenty.

Now heres the crux. the distance from the switch to the socket will be about 26 metres. The garage is detached at the back of the house.

I realise about V drop over distance but can't work if to use 2.5mm or 4.mm SWA?? I'm swayed to go with the 4.0mm just to future proof my self in case I want to use a bigger load in future.

Any advice would be helpful.[/quote]

HOLDBACKTHERIVER
SEE DOC S PART P PROJECT SECTION.
THIS WORK OUTDOORS IS PART P NOTIFIABLE.
YOU COULD ENLIST A PART P SPARK TO HELP U
WITH YOUR QUESTIONS.

BLAKEY1963
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Postby sparx » Fri Oct 12, 2007 9:25 pm

Hi leaving out other issues for a minute,
your volt drop issue is very valid but not easy, you need to assess total load on whole circuit from house con. unit to garage, work out V-D for that part of run then add in load for skt at end of run and work out V-D for that using both 2.5 & 4.0mm.
? would there be any additional load on garage whilst using Karcher?, unlikely, so what is supply cable to garage, how far from C-U @ 2 kw ie 8.4 Amps approx work out V-D to garage, then work out @ 8.4 A for run from garage to outlet,
total V-D not to exceed 9.2volts
If you state type of cable . length of run method of run ie 'clipped direct' of cable to garage,then can calc.V-D for that part, then assuming SWA for run to skt can work out cable size which 'gut feeling' says at least 4.0mm,
regards SPARX
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