Re-doing workshop (elec questions)

[Kent]

Looking to do some extensive work on the shop this year. Re-roof and raise get a nice level floor in, chuck and sell a load of stuff I don't use, get proper extraction in place etc. etc. These jobs just tend to grow so its getting done off plan and on cost / finished on time

On the drawing board at present and have a pretty good idea how I am setting things up but I don't know how to do the electrical calcs as regards if I need a new supply cable and how to state the total max running load I should stipulat.

Here is what I want to put in (all single phase)
20 off LED bright white spots into ceiling
1 off 24.5 amp welder supply with three options to plug in around the place (only running one though)
1 off 32 amp welder supply again three option points with only one in use at a time
the above 32 / 24.5 supplies might feasibly be used at the same time

750 w extraction
1100 w saw
1100 w drill

8 off double sockets (max four or so in use at a guess really more about were I need them for grinders / chargers and such)

Obviously even with two persons in there we couldn't run the lot at one time so its obviously not a straight forwards addition.

I already have a supply in that was put in only a few years ago but it is fused at another outbuilding be good if it was ok but I suspect it will be a new cable from the meter and keeping that for the lights and 13amp sockets with some slack. Like I say its not my thing

 

[Fintray]

At a rough calc about 14kW max load, both welders on max, extraction and lights on, though unlikely that you will have both welders at max at same time!

 

[danman]

I have done my shed,done 6 double sockets with a B6 breaker,for grinders/chargers/drills ect,1double socket for chopsaw and 9inch grinder only with a 32A breaker,bit big but ok with 4.5 mm cable,no loop back to box an 32A welder plug box for welder plug with32A breaker fuse with 4.5mm cable.Looped sockets back to breaker box for safety so no leccy shock off sockets an wired my extracter fan to a plug an swith on as needed,not a leccy but got info off leccy's at work.
It all works great an chopsaw an large grinder don't trip anymore so a winner,took supply from house with 20mm armoured cable that i buried,as i say not a leccy but all works perfect

 

[steviec_lj]

Looking to do some extensive work on the shop this year. Re-roof and raise get a nice level floor in, chuck and sell a load of stuff I don't use, get proper extraction in place etc. etc. These jobs just tend to grow so its getting done off plan and on cost / finished on time

On the drawing board at present and have a pretty good idea how I am setting things up but I don't know how to do the electrical calcs as regards if I need a new supply cable and how to state the total max running load I should stipulat.

Here is what I want to put in (all single phase)
20 off LED bright white spots into ceiling
1 off 24.5 amp welder supply with three options to plug in around the place (only running one though)
1 off 32 amp welder supply again three option points with only one in use at a time
the above 32 / 24.5 supplies might feasibly be used at the same time

750 w extraction
1100 w saw
1100 w drill

8 off double sockets (max four or so in use at a guess really more about were I need them for grinders / chargers and such)

Obviously even with two persons in there we couldn't run the lot at one time so its obviously not a straight forwards addition.

I already have a supply in that was put in only a few years ago but it is fused at another outbuilding be good if it was ok but I suspect it will be a new cable from the meter and keeping that for the lights and 13amp sockets with some slack. Like I say its not my thing

Demand and diversity. Domestic stuff is as follows, I used the same calculations for my workshop;
Lighting - 66% of total current demand for each circuit
Power - 100% of the first ring circuit + 40% of all other circuits

I have done my shed,done 6 double sockets with a B6 breaker,for grinders/chargers/drills ect,1double socket for chopsaw and 9inch grinder only with a 32A breaker,bit big but ok with 4.5 mm cable,no loop back to box an 32A welder plug box for welder plug with32A breaker fuse with 4.5mm cable.Looped sockets back to breaker box for safety so no leccy shock off sockets an wired my extracter fan to a plug an swith on as needed,not a leccy but got info off leccy's at work.
It all works great an chopsaw an large grinder don't trip anymore so a winner,took supply from house with 20mm armoured cable that i buried,as i say not a leccy but all works perfect

6 Double sockets on a B6 breaker?
1 Double socket on a 32a breaker?
4.5mm cable?

Chopsaw and grinder won't trip, as they won't pull anywhere near 32a, and the socket will melt before the breaker goes anyway!

20mm armoured cable?

A catalog of errors, and I'm surprised it hasn't burnt down yet.

 

[brokenbiker]

I have done my shed,done 6 double sockets with a B6 breaker,for grinders/chargers/drills ect,1double socket for chopsaw and 9inch grinder only with a 32A breaker,bit big but ok with 4.5 mm cable,no loop back to box an 32A welder plug box for welder plug with32A breaker fuse with 4.5mm cable.Looped sockets back to breaker box for safety so no leccy shock off sockets an wired my extracter fan to a plug an swith on as needed,not a leccy but got info off leccy's at work.
It all works great an chopsaw an large grinder don't trip anymore so a winner,took supply from house with 20mm armoured cable that i buried,as i say not a leccy but all works perfect

so you have 12 off 13amp sockets on a 6 amp breaker? that's an interesting one. where did you get 4.5mm cable from? and 20mm armoured from the house? bet that was pricey...

from what you have said there I suggest you disconnect it immediately and get an electrician in to have a look at what you have done and check it is right, because from that description nothing makes any sense really. oh and when you say no loop back to box i really hope you don't mean you haven't earthed anything as that would be really daft, but then again from the rest of the description nothing else makes much sense.

 

[Robotstar5]

As the above posts, disconnect for safety and get a sparky in.

 

[Robotstar5]

Here is what I want to put in (all single phase)
20 off LED bright white spots into ceiling
1 off 24.5 amp welder supply with three options to plug in around the place (only running one though)
1 off 32 amp welder supply again three option points with only one in use at a time
the above 32 / 24.5 supplies might feasibly be used at the same time

Standard industrial (commando) sockets are available in 16A & 32A, never heard of 24.5A so do them all in 32A.

 

[danman]

Fair enough

 

[danman]

My mistake,sockets on a B16 chopsaw an grinder on a D16 an armoured cable is 6mm,whoops

 

[Woody.v8]

so you have 12 off 13amp sockets on a 6 amp breaker? that's an interesting one. where did you get 4.5mm cable from? and 20mm armoured from the house? bet that was pricey...

from what you have said there I suggest you disconnect it immediately and get an electrician in to have a look at what you have done and check it is right, because from that description nothing makes any sense really. oh and when you say no loop back to box i really hope you don't mean you haven't earthed anything as that would be really daft, but then again from the rest of the description nothing else makes much sense.

I have 35mm from house to workshop coz i,m special

 

[brokenbiker]

I have 35mm from house to workshop coz i,m special

Yeah but that's different lol

 

[brokenbiker]

Standard industrial (commando) sockets are available in 16A & 32A, never heard of 24.5A so do them all in 32A.

I think 24.5A was just a reference to the max input to the welder, but agreed it needs a 32A socket

 

[brightspark]

I have 35mm from house to workshop coz i,m special

ive got 35mm armoured to my shed cos i got 50 meters for nowt .used 20 m and sold the rest

 

[mechman]

I got mine for nowt in aal (Geordie speak)

 

[Robotstar5]

I got mine as part of my redundancy package

 

[brightspark]

I got mine for nowt in aal (Geordie speak)

have u emigrated from newcastle to lincs then

 

[mechman]

Aye

have u emigrated from newcastle to lincs then

 

[mechman]

have u emigrated from newcastle to lincs then

Aye Its caald gannin naatiff.

 

[dannyp]

with how cheep consumer units and breackers are now i dont understand why people skimp on them.

lighting cuircuits nice and small plenty of them, i'm now rocking a whole consumer unit just for lighting cuircuits. that way if a fault develops i don't loose all my lights and its easy to find. ( most of the lights are s/h floresents so the units do pop every now and again and kick the breacker )

fixed kit, that got another consumer unit. then everything is hardwired from the unit with ether a ( token ) fused outlet or isolator with the right sized breaker.

and the sockets on another sockets

32A blue sockets C32 's

then 2 rings of 6 13A double sockets they get a B32


latest mod as i'm allways worried about stuff getting left on is a big contactor, 1 littel switch everything is off

 

[Robotstar5]

latest mod as i'm allways worried about stuff getting left on is a big contactor, 1 littel switch everything is off

The control side of the contactor would need to remain live to operate it, if for any reason it dropped out while you were working, you would be left without lighting.

Easier option would be a main isolator switch, pull a lever instead of pressing a button?.