Shed Power

[DippySteph]

I am looking for some help and advice please.
I am a single working mum of two with little DIY experience.
I have recently had a small log cabin build in my garden, I am now looking at getting power to it. I have had three electricians around to quote for the work.
They where all given the same verbal brief but the specs they have come back with appear completely different so unsure which is best.
The only similarities between the quotes appear to be:
Fit 3, 4ft Led battens.
Fit 6 double sockets
Test and certification

Electrician 1
Install new 60A switch fuse
Run 18m, 10mm 6943X, relay paving and make good grass
Install new 2 way CU in shed

Electrician 2
Install new 80A fused switch
Lay, 10mm armoured cable, customer to sort garden
Install earthing rod.
Install new 2 way CU in shed

Electrician 3
Feed shed via 6mm twin and earth. Cable run via conduit attached to garden wall
Install new 2 way CU in shed

I am a amatuer wood turner, I will have a small lathe, bench sander and a pillar drill in the shed.
Not sure if it makes a difference but I live in Elgin, Moray

Thank you

Steph

 

[Spark123]

6943X is SWA so it looks like no 1 and no 2 are similar in that respect, though 10mm SWA is usually only rated for 60A so no 1 is winning in my eyes!
(We normally only use it up to a maximum temperature of 70°C, XPLE can be used to 90°C but needs special considerations for it's terminations, even then it probably can't take 80A).
Stuck in a conduit on a permanent structure is OK but may not be aesthetically pleasing!!
What are you going to use in there that takes all this power?

 

[Robin0577]

1 and 2 are very similar, apart from not making good the garden afterwards. 6945X is the British standard number of a type of armoured cable. Query the 80A fused switch though, 60A is more likely correct but the 80A unit could easily be fitted with a 60A fuse. Without seeing the site I can't tell you if the specification is all correct but it appears reasonable.

3 is really not a such nice way to do the job, I'd be inclined to ignore that one.

 

[EFLImpudence]

Does 60A or 80A make any difference if the load in the shed is limited to less than 60A? - subject to fault current being satisfactory.

 

[ericmark]

I will start in reverse, the lathe and rest of the motor driven units can be powered by either a single phase motor or a three phase motor and inverter, the latter needs a lot less to start the motor, so it is very important to know the start current.

I have two fridge/freezers the new one max power is 110 watt when the de-frost heater cuts in, the motor uses around 70W both run and start. The old one still 70W run but on start it uses 2000W only for a few seconds, but in a shed that would mean the cable needs to be a lot heavier.

Without an inverter controlled motor the start current can vary wildly. Often one is unaware of how much they use on start up. Using inverter drives may well reduce the cost of wiring as well as giving you more control over the equipment. Capacitor start can have a huge inrush on start, but some items have AC/DC motors which are nearly as good as inverter control.

So step one is look at what you are using.

 

[mfarrow]

Go for 1. If he'll dig your trench and make good for a reasonable total then there's no hassle with other trades (eg garden labourer).