Workshop Power (Electricians wisdom needed)

[SkinnyB]

Hi

First time poster long time browser…

I have finally got around to sorting out my workshop and I am now in need of getting the place powered.

I have had a quote from my electrician and he has quoted £750 (£100 Labour & £650 Materials)
I just wanting to know if this seems about right.

The workshop is 40m from the house.
I asked for:
x2 16amp single plug sockets
x6 double standard plug sockets
x1 double exterior plug socket

Lighting:Ill be running x4 65 watt bulbs
Heating:3000 watt heater (Winter)
Tools:2200 watt dust extractor, 2000 watt planer (16 amp)
Total: Roughly 7500 watts peak

This is the info i gave my electrician for him to work out costs. (wasn't sure exactly what he needed.)

I know nothing about this stuff really but if someone can shed any information on what
i should expect and what kind of cable I will be needing based on the info above that would be very helpful;
which sort of leads me onto my next question...

Secondly i have some 50m cable which i got for free recently; has 16 amp plugs on each end. (Thought that I may be able to use it…)
Looking up the writing on it, it comes across as:

H07RN-F
Conductors x cross-sec. mm2: 3G2.5
Outer Diameter. mm: 10.9 - 14.0
Cop. weight kg/km: 72.0
Weight ca. kg/km: 235.0
AWG: 14

Is this any good for anything?

Thanks for taking the time to read :lol:

 

[carlb40]

Can't help with the rest, but 14 gauge cable - your free one is only good for 15 amps. So it won't be of any use for the supply to the workshop.


Wish my cable run was only 40mtrs. Mine is 100mtrs :shock:

 

[ballibeg2]

Your electrician will need to calculate the voltage drop over the distance.

http://www.calculator.net/voltage-drop-calculator.html

An armoured cable is required and needs to be buried at the required depth. If you're running a buried power might as well shove in an internet cable cat5e.

Armoured cable very expensive.

Dave

 

[MMUK]

For a 40m run, I would recommend 6mm armoured. You would get away with 4mm but that doesn't leave much room for potential expansion of the circuits.

I would connect this before your main consumer unit with an 80A main switch and fit a separate consumer unit in the workshop. I'd use at least an 8 way unit so there's room for expansion. To err on the side of caution, I would split your double sockets onto two 32A ring mains. Again this allows for possible expansion. The two 16A sockets could both be fed from a single 32A RCD and I would fit the outdoor socket to it's own separate 16A RCD. Obviously 6A for lighting. This will leave a couple of spare ways in the board.

I would recommend using low voltage lighting rather than normal mains voltage and I would suggest you seriously consider LED strip lighting. It's a much better light output, there's no flicker and it's much cheaper to run.

 

[MARK.B.]

Ask him for another quote to include the supply of power from your house to workshop including seperate fuse box, rcd, perhaps get him to include a master cut off switch to disable the supply to some or all of the sockets. Anything else you want fitted get it now as its more expensive to retrofit later . Personally i would get at least 3 quotes and make sure that whoever does the work is suitably qualified and able to issue you with the required installation paperwork .

 

[flying haggis]

I would agree with the suggestion of 6mm cable but to future proof your self I would put in at least 10mm, and in the same trench but about 3-4 ins apart I would put in a 50mm duct with a draw rope in case you want to add computer/alarm/telephone etc

http://www.tlc-direct.co.uk/Technical/C ... eDrop.html

 

[Halo Jones]

Hi,

From your quote I would have said that man hours was low and fixings was high but overall it seems reasonable.

Not sure how big your shop is and how many things you will be running at once. I needed about 25-30 m SWA for mine and from memory I calculated that 6mm would give me ~10 kW.

So assuming the things that might be running at once in a one man shop:
Heating 2 kW
Lighting 0.1 - 0.5 kW
dust extractor 2 kW
Table saw or planner thicknesser 2 kW
compressor? 1 kW
Total ~7.5 kW

Therefore 6mm was way fine for me, but you need to go through the same thought process.

Goodluck

H.

 

[fred55]

I would endorse the above suggestion. I have just finished my shed at the end of the garden and used 10mm armoured bigger than required - regrets 1. fuse box too small (only 3 fuses lights, power, doors) 2. wish I put in internet cable/landline phone line although I did use a 50mm pipe and leave a draw rope in just in case but will never get around to using it. And the wife would like to add put in water and a bed ? don't know why.

 

[Grahamshed]

I would agree that it seems a little low for man hours.
The total is marginally less than I paid but I had more done so it seems reasonable.

 

[flying haggis]

if you use SWA 3 core XLPE it has a higher current capacity than SWA 3 core PVC,

using the calculator I linked to it gives a max cable load using XLPE as 54Amps

 

[carlb40]

if you use SWA 3 core XLPE it has a higher current capacity than SWA 3 core PVC,

using the calculator I linked to it gives a max cable load using XLPE as 54Amps

:shock:
I just tried that site. With my 100mtr run and allowing for lights to be on and using 2.2KW PT and 2000 watt extractor i need 16mm cable :shock: :shock: :shock:

 

[flying haggis]

if you use SWA 3 core XLPE it has a higher current capacity than SWA 3 core PVC,

using the calculator I linked to it gives a max cable load using XLPE as 54Amps

:shock:
I just tried that site. With my 100mtr run and allowing for lights to be on and using 2.2KW PT and 2000 watt extractor i need 16mm cable :shock: :shock: :shock:

would it be cheaper to move the workshop :roll:

 

[carlb40]

if you use SWA 3 core XLPE it has a higher current capacity than SWA 3 core PVC,

using the calculator I linked to it gives a max cable load using XLPE as 54Amps

:shock:
I just tried that site. With my 100mtr run and allowing for lights to be on and using 2.2KW PT and 2000 watt extractor i need 16mm cable :shock: :shock: :shock:

would it be cheaper to move the workshop :roll:

Wish i could. Thinking about extending it slightly by about a metre or so. So that should knock a bit off the cable price. :lol: