Lost an argument

[alexmark]

Hi
A customer recently demolished a green house and erected anew one in the same location. ZThey required that the new green house wasfitted with a 5 foot florescent light 2 13amp double sockets and 2 switchedfused spurs.
This was all to be run back to a new consumer unit which hadto be a 4 way box as the second green house is to be rebuilt next year and theywant the same installation on that site.
Here is my problem and how I see the situation.
The old green house was feed from a board in a potting shedthat was supplied by a 6mm armoured cable that is 86 meters long. The control panelthat feeds this cable is a sub board from the main house and is fed with a20amp breaker.
The consumer unit at the other end where the potting shed isfeeds, a well, potting shed used as a place for breaks for the gardeners eg.microwave, kettle etc and also feeds the second greenhouse a 13 amp doublesocket and a light.

The property is a private estate.
I would like to hear peoples view points on this as I amtold that basically the 20 amp breaker negates the problem of having toincrease the armoured cable size for voltage drop etc.
If I boil a 1 kw kettle the voltage drops 5volts.

 

[Darkwood]

Re: Lost on argument

Welcome to the forum alexmark, volts drop is probably least of your worries here, complying to permitted Zs values would be my first thought.

 

[Spoon]

Re: Lost on argument

Also 20A on 6mm SWA cable over 86 meters is more than 3% for lights.

 

[Leesparkykent]

Re: Lost on argument

At 20A 10mm would even be touching cloth by the time the final circuits are connected to the sub board with regards to volt drop and lighting circuits.

 

[LankyWill]

Re: Lost on argument

can you tt the submain part and increase the size of the armoured? Seeing as sharp objects and used by gardeners i would also be worrying about Zs values. What do your calcs say?

 

[telectrix]

Re: Lost on argument

At 20A 10mm would even be touching cloth by the time the final circuits are connected to the sub board with regards to volt drop and lighting circuits.

struggling to find as reg about touching cloth. is it to do with 3rd amd. about non-combustible cloth?

 

[happysteve]

Re: Lost on argument

struggling to find as reg about touching cloth. is it to do with 3rd amd. about non-combustible cloth?

I believe so:

421.1.301: Within private estates with long runs to potting sheds and such like, cloth which is in contact with distribution circuits shall comply with BS EN 98765-4 and shall:

(i) be manufactured from a non-combustible material, or

(ii) be enclosed in shirts or trousers manufactured from a non-combustible material and complying with Regulation 132.12.

NOTE 1: Ferrous metal, e.g. steel chain mail or armour is an example of non-combustible material. So might other things.

NOTE 2: The ambiguity is intentional. We are professional trolls.
​

 

[alexmark]

Re: Lost on argument

I believe so:

421.1.301: Within private estates with long runs to potting sheds and such like, cloth which is in contact with distribution circuits shall comply with BS EN 98765-4 and shall:

(i) be manufactured from a non-combustible material, or

(ii) be enclosed in shirts or trousers manufactured from a non-combustible material and complying with Regulation 132.12.

NOTE 1: Ferrous metal, e.g. steel chain mail or armour is an example of non-combustible material. So might other things.

NOTE 2: The ambiguity is intentional. We are professional trolls.
​

I think close to the cloth was just a saying not a comment about cloth

 

[Darkwood]

Re: Lost on argument

I think close to the cloth was just a saying not a comment about cloth

I think they know that, it was just 'in house' jovial banter or more commonly known as taking the urine

 

[happysteve]

Re: Lost on argument

I think they know that, it was just 'in house' jovial banter or more commonly known as taking the urine

Indeed. Sorry for derailing the thread...

 

[Welchyboy1]

Re: Lost on argument

Real world answer here

its a potting shed!

Worst case youll likely get is the fluroescent will dip out temporarily when you put the kettle on, the install will likely not see 20a for any duration of time if ever

if the 6mm is allready in place then leave it alone and crack on, it wouldnt concern me in the slightest

Check your zs then TT/rcd if required

if you was feeding a 100A supply to a TPN workshop at 86 meters i would be more concerned

im sure your client will agree to leave it when handing him a quote to renew the submain to 86 meters of 16mm SWA!

 

[Big Sausage]

Re: Lost on argument

Best to stay out of a potting shed if your called "Davis" and wear a set of overalls with yellow strips down the side!

 

[Leesparkykent]

Re: Lost on argument

Best to stay out of a potting shed if your called "Davis" and wear a set of overalls with yellow strips down the side!

haha mg_smile:

 

[7029 dave]

Re: Lost on argument

Best to stay out of a potting shed if your called "Davis" and wear a set of overalls with yellow strips down the side!

You old bugger, scum great film.