Power and wiring for back shed

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  #1  
Old 12-01-17, 11:12 AM
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Power and wiring for back shed

new circuit is going to be run from main house board .. shed is 15 meters away ..

6mm twin and earth in condit run underground

the new 6mm circuit is going to be run off a 25 amp cb

the new circuit will feed lights and gpos in shed on the same circuit

im not 100% sure that the cable is best with 6mm
im also not sure if a 25amp cb is best for this circuit ..
not sure if shed should have its own sub board ..

thank you ..



Mod note: member is from Austrlia
 

Last edited by PJmax; 12-01-17 at 04:45 PM.
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  #2  
Old 12-01-17, 02:53 PM
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No location in your profile so no one's going to know what your local codes are, or even the voltage your working with.
At least 99% of the people on this site are in the US.
Tried the search function at the top of the page?
This one question has been asked and answered hundreds of times.
 
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Old 12-01-17, 04:49 PM
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Your 6mm wire is equivalent to our #10 wiring. Here, in the States, #10 wiring is rated for 30A and is protected by a 30A breaker.

Here again, by code, you cannot connect a standard receptacle to a circuit over 20A. That means we would be required to use a sub panel (board) at the shed end with a 15A or 20A breaker.

In Australia since you have 230/240v power..... your code requirements may be different. You should consult a local code authority for clarification.
 
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Old 12-02-17, 04:53 AM
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hey joecaption, i live in Australia and we have 240volts ..

thanks for your input ..
 
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Old 12-02-17, 04:57 AM
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hey pjmax,

thanks for your input ..

6mm in conduit underground with a 30amp cb from the main switch board sounds like the go .. gpo's and lights will be run off this combined circuit ..

thx ..
 
  #6  
Old 12-08-17, 08:52 AM
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wiring up a backshed subboard

hey guys, Australia here ..

6mm twin & earth, ran from the main switchboard too the back shed ..

backshed subboard has 2 circuits .. light and power .. 20 mcb 10 mcb ..

can any off you guys tell me what amp rcd i should use ..

thank you ..
 

Last edited by lifesaver1982; 12-08-17 at 09:10 AM.
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Old 12-08-17, 09:33 AM
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Hi,

Since your wiring methods are different from ours here in the States..... I combined your two threads. Not sure of the correct answer.

You have a 30A circuit there with a 20A and a 10A breaker. The RCD would need to be able to handle 30A of power. Not sure what sizes they come in.
 
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Old 12-08-17, 10:34 AM
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thanks for your quick reply pjmax and sorting out my previous posts on this one thread .. ive searched the internet for hours for your answer ..

yes .. my 2 circuits are equal too 30 amps (light & power) and you said the new rcd has too handle at least 30 off those amps ..

my local hardware stocks a 32amp rcd ..

so now my final question is .. "a 32amp rcd would be the correct one too install in my sub board ??"

thanks again ..
 
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Old 12-08-17, 12:15 PM
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Don't know rules down there but 25amps sounds too big for a single general purpose circuit.
32 amp rcd would be for the entire sub panel/board/consumer unit. It needs to be sized to handle the max load - in your case 25 amps of the upstream breaker. Then a couple individual breakers for circuits. Might be 16amp in your region.

Regardless of this you need to find out what your local rules are. Even if no permit is needed there are rules.
 

Last edited by Astuff; 12-08-17 at 12:56 PM. Reason: removed redundant info
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Old 12-08-17, 01:58 PM
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yes, 25amp mcb is too big for 2.5mm, that why a 20amp mcb will be used for 2.5mm

25 amps off the upstream breaker ?? (what's that mean ??)

thanks for your input Astuff .. 👍👍
 
  #11  
Old 12-08-17, 03:35 PM
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Yes, from your earlier note you stated that the mcb in the house panel (consumer mains switchboard?) was going to be 25 amp. So the maximum the shed panel has to deal with is 25 amps. If both the 10 and 20 max out you will trip the 25 - the panel will never see 30 amps.

The rcd can be higher but still will be safe - whatever size it still protects/trips at 30ma. Assume the rcd is a combo rcd and breaker (mcb) so also serves as a panel disconnect.

Still - local code may require the mcb part of the rcd be sized the same as the upstream 25amp. Or even change both to a 30amp. Lastly, in the states it is also required that ground rods/earthing electrodes or similar is installed for remote buildings.
 
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Old 12-10-17, 01:27 AM
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so what amp RCD should i use in my sub-board, thanks ..
 
  #13  
Old 12-10-17, 08:30 AM
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Use the 32amp rcd. It is safe to use. If you ever get things inspected and they want you to put something else in it is easy to change out.
 
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Old 12-11-17, 03:13 AM
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thanks astuff,

ive decided too use two devices for the shed, they are ..

10amp rcd/mcb
20amp rcd/mcb
30mA

each device is a combination off the two in one ..

this was reccommended by the electrical sales guy behind the counter ..

two off these devices are both clipsal brands .. i was going too go Deta but i want something that's good quality ..
 
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Old 12-11-17, 06:38 PM
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Sounds like a good choice.
 
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Old 12-11-17, 07:48 PM
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thanks pjmax ..

it was either this way or too buy 3 devices ..

1 rcd and 2 mcb's

both ways do the same job ..

thx ..
 
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