advice / help needed on garage electrics

[bunnymofo]

How are you measuring it ? Peak to peak or RMS ?

A 230v RMS supply will give you around 320v peak to peak

A "theoretical" single device (i.e. a theoretical heater) that draws 12kw at 230v will take around 52 amps. If however you plug this into a 284v RMS supply then it will take up to 14.8kw.

Plugging this value in to the cable calculator comes up with 16mm2 cable so I'd go that way to be on the safe side and limit the maximum total value of your appliances to 12kw (when rated at 230v).

i didnt get half of that haha. i think the most that wil be being used will be the lift, 32A and some lights, sterio, heater (diesel so dosent use much electric). so i will se about teh price of 10 and 16 mm, and see what i can aford lol

[king nero]

Whats a TN-S powergrid ?

Where the powercompany supplies 3-phase power + neutral, with the neutral earthed at the local transformator (starpoint = neutral), and where you have to "make" your own earth by either a loop under your house or cupper sticks hammered into the ground.

I don't quite understand your values, I thought UK had standard 230V supply (neutral + phase)?
That would either mean 3x230V transformators (delta grid) without neutral (but you can't have 110V then) or a 3x400V (star) grid with neutral, but you can't measure 260-280V in either case!

But that's not that important, what is important is securing your cables correctly (right amps breakers), which calculates from the voltage you have available, and securing your personal safety with the device I mentioned before (which is also very important!).

[MSG]

You can always run seperate circuits (wiring) for each heavy appliance, so won't have to go and buy a real thick wire to supply the entire load, that will not only cost a lot but difficult to hadle and terminate and all wiring should be preferabley conduited, so from your house distributer board run seperate cables supplying power to your lift, seperate for mains ring, seperate for welder, and eperate for lighting, this will also avoid any lights dimming considerably when you switch on heavy loads due to surges.

The fact is there is a duty cycle to consider, so for example a lift would not undually heat the cable since it will only ever be on for what two minutes maximum to raise the lift, like wise a welder would be not welding co0nstantly for more than a few minutes at a time, the most annoying thing would be lights dimming each time you press the weledr trigger.

[bunnymofo]

Where the powercompany supplies 3-phase power + neutral, with the neutral earthed at the local transformator (starpoint = neutral), and where you have to "make" your own earth by either a loop under your house or cupper sticks hammered into the ground.

I don't quite understand your values, I thought UK had standard 230V supply (neutral + phase)?
That would either mean 3x230V transformators (delta grid) without neutral (but you can't have 110V then) or a 3x400V (star) grid with neutral, but you can't measure 260-280V in either case!

But that's not that important, what is important is securing your cables correctly (right amps breakers), which calculates from the voltage you have available, and securing your personal safety with the device I mentioned before (which is also very important!).

sorry, bit i didnt get half of that either lmao

[bunnymofo]

You can always run seperate circuits (wiring) for each heavy appliance, so won't have to go and buy a real thick wire to supply the entire load, that will not only cost a lot but difficult to hadle and terminate and all wiring should be preferabley conduited, so from your house distributer board run seperate cables supplying power to your lift, seperate for mains ring, seperate for welder, and eperate for lighting, this will also avoid any lights dimming considerably when you switch on heavy loads due to surges.

The fact is there is a duty cycle to consider, so for example a lift would not undually heat the cable since it will only ever be on for what two minutes maximum to raise the lift, like wise a welder would be not welding co0nstantly for more than a few minutes at a time, the most annoying thing would be lights dimming each time you press the weledr trigger.

i will see how many spare slots there in my consumer unit in the house, and price the cable to do ti seperate, and to wire it all in one big cable. i dont mind the lights dimming when i use the welder, and anyway, when i welt it dims the lights in the house and everywhere else anyway lmao

[MSG]

You should also be aware that using a common RCD in the single supply feed to the garage is not a good idea as upon a fault on any appliance or wiring can suddenly trip the RCD and you could loose all power everywhere including lighting as well as leaving you in dark to work your way out, and you could trip on your trolly jack, bang your head on the lift or trod on your workshop cat and accidently kick your pet dog's bolloxes, so I would highly reccomend seperate feeds each seperately proteceted using indepenedent RCD's as this will give you complete independence, so if you get a fault on one circuit you won't loose power on others. Use a second distribution switch board for the workshop distribution.

[bunnymofo]

You should also be aware that using a common RCD in the single supply feed to the garage is not a good idea as upon a fault on any appliance or wiring can suddenly trip the RCD and you could loose all power everywhere including lighting as well as leaving you in dark to work your way out, and you could trip on your trolly jack, bang your head on the lift or trod on your workshop cat and accidently kick your pet dog's bolloxes, so I would highly reccomend seperate feeds each seperately proteceted using indepenedent RCD's as this will give you complete independence, so if you get a fault on one circuit you won't loose power on others. Use a second distribution switch board for the workshop distribution.

so, if u supply it with a single breaker in the house, then go to a consumer unit in the garage with seperate ones, and just have 13A sockets with built in rcd. instead of a main one, will that be ok ?

[Dom]

MSG actually spoke some common sense there .......

I work in a workshop which is built inside my garage. There are 2 doors to get out of and no natural lighting.

I was working on a project which involved some pretty industrial electronics and two pieces of kit didn't behave themselves and tripped the main house breaker. Not only did I get a minor zap from it, a quick flash before my eyes but all the electrics and lighting in the workshop/garage went off. I had to feel my way to the main doors to get back to the house to reset the main breaker.

I have an app on my phone now which doubles as a torch as well as torches in strategic places around the workshop lmao

[bunnymofo]

MSG actually spoke some common sense there .......

I work in a workshop which is built inside my garage. There are 2 doors to get out of and no natural lighting.

I was working on a project which involved some pretty industrial electronics and two pieces of kit didn't behave themselves and tripped the main house breaker. Not only did I get a minor zap from it, a quick flash before my eyes but all the electrics and lighting in the workshop/garage went off. I had to feel my way to the main doors to get back to the house to reset the main breaker.

I have an app on my phone now which doubles as a torch as well as torches in strategic places around the workshop lmao

ahh, lmao i might just put in a coupple of emergency lights then, so that of te opwer dose go off i can still see but, i have a mini torch on my keyring anyway

[MSG]

so, if u supply it with a single breaker in the house, then go to a consumer unit in the garage with seperate ones, and just have 13A sockets with built in rcd. instead of a main one, will that be ok ?

Sorry to come back to this a little late, yes that will work fine, since the rcd will only trip your socket circuit and not the others.

[bunnymofo]

Sorry to come back to this a little late, yes that will work fine, since the rcd will only trip your socket circuit and not the others.

ahh, ok, thanks

[bunnymofo]

so, wheres the best / cheapest place to buy 10mm T&E ?

[MSG]

Search around for best prices mate, people like WF (wholesale fittings) who supply bulk of wiring and switch gear to the electrical contractors can do a great deals, even possible to buy cheaper on ebay but not sure of the quality may be por if the cable has been imported from certain countries known to produce impure copper cables, this includes China and India, so best to buy British manufactured cable.

[bunnymofo]

Search around for best prices mate, people like WF (wholesale fittings) who supply bulk of wiring and switch gear to the electrical contractors can do a great deals, even possible to buy cheaper on ebay but not sure of the quality may be por if the cable has been imported from certain countries known to produce impure copper cables, this includes China and India, so best to buy British manufactured cable.

ahh ok, thanks. i will try WF and cpc. i looked in b&q but they only have 25 meters and i need 30 yes, i will stick to british made, i will also try carbootsale. see if i can get a half roll or something.

[MSG]

I think due to the nature of this cable, it is sold either in drums of 25m or 100m, so you will have plenty left over if you went and bought a full 100m reel, not sure if anyone does a 50m reel. I am sure any an electrical retailer might offer you a better price for 30m as they sell per meter so it is a question of asking and them having enough on their drum.

[bunnymofo]

ahh, thats not good lol. i thaught i would be able to get a 50 M roll i have a roll with a little bit left on, im going to look at it and see what it says, i will post it up in a minute

[bunnymofo]

the one ihave is a 50 meter reel. but tere not enough on it so il have to look for more.

[MSG]

RS Components do a 50m reel of T&E in both 10mm and 16mm, £134 and £203 respectively plus VAT.

check their website, you can orrder using your card if you are not an account customer. Cables | Electrical/Power | Ring Main and Lighting Cables 4294954854&selectAttribute=10.0mm²#breadCrumb

[bunnymofo]

RS Components do a 50m reel of T&E in both 10mm and 16mm, £134 and £203 respectively plus VAT.

check their website, you can orrder using your card if you are not an account customer. Cables | Electrical/Power | Ring Main and Lighting Cables 4294954854&selectAttribute=10.0mm²#breadCrumb

thanks, il have a look

[Frisco]

Try a normal electrical wholesale place mate, RS are generally expensive

[bunnymofo]

Try a normal electrical wholesale place mate, RS are generally expensive

ok. thanks

[Dom]

If you've got 30m of wiring to do and its going to run outside then seriously consider buying SWA (armoured cable). Normal cable will degrade in sunlight and there is the chance of chopping through it by accident.

[bunnymofo]

If you've got 30m of wiring to do and its going to run outside then seriously consider buying SWA (armoured cable). Normal cable will degrade in sunlight and there is the chance of chopping through it by accident.

i have thaught of that, but its even more expensive, so, i am going to run the T&E inside alkathene piping. and most of it will be under the ground, none of it will be in the sunlight

[Dom]

30m of 16mm 2 core SWA comes in at around £120 inc VAT - pretty bombproof stuff as well.

https://www.electriccableco.com/electric-cable-shop.htm

* That may not be the best price but doesn't seem too bad from what I paid for mine ages ago

[bunnymofo]

ahh, thats not so bad