Thread: Midnight's Shed

Originally Posted by riverbuilder

Studs at 600 centres is the go. How thick is the ply? Is it perforated ply? Is this the same shed started in April 2019 or another one?

Hey Riverbuilder Studs are 600 on centre, and the ply is 15mm. And yes, it's the same project started at the front end of this thread, back in April 2019. We don't get a huge amount of time out there to work on it, as you might guess by the pace of progress to date!

Originally Posted by Bohdan

Since a 10A plug will plug into a 15A socket and the fuse is only there to protect the wiring you may as well have the sparky fit 15A outlets from the start and save the potential recall and replacement powerpoint cost.

Bernmc got it right in his post - a 15A GPO I can get for around $52.00 at the moment. I can get a 10A GPO for around $4.00

I have a plan for about 15 power points (plus minus a couple when the final wall gets built). Whilst I know I will need probably 3 of them at 15A outlets, the other 12 will end up costing $576.00 less using 10A outlets. Over time, I will figure if any need to be swapped, and have a single call out to swap them over, probably combining that with some other work around the house. Losing the $4.00 for each 10A that is replaced is negligible, and it makes a big dent on the costs now.

Depends where you shop. $7.95 or $146.08

Originally Posted by Bohdan

Depends where you shop. $7.95 or $146.08

Certainly seems so - many thanks for that link! Given that information, I'm glad I haven't yet gotten around to ordering the powerpoints, and it seems they will all now be 15A from the outset.

Hi MM

I was under the impression that a 15A domestic circuit was only permitted one 15A powerpoint. When I had a 15A circuit installed a couple of years ago to run my welder, jointer and bandsaw the electrician installed a 15A single pendant for the jointer and bandsaw in the middle of the shed and a 15A single powerpoint next to the switchboard for the welder (I always weld outside - sawdust and wood shavings don't mix with weld spatter). He told me he wasn't supposed to install two outlets on a single domestic 15A circuit but he made an exception only because I wouldn't be using the welder and the jointer at the same time.

I'm not wanting to put a dampener on your shed fitout (although I am envious) but I am interested in how the circuit breakers would behave if the 15A circuit was overloaded. It would be a real pain in the butt to have them constantly tripping due to excessive load.

Regards
Twosheds

I am no electrician but apart from any code requirements how would it matter if they were 15 or 10 amp outlets?
The circuit breaker can only react to the load so it will all come down to the load you put on the circuit via what items you choose to run concurrently
Cabling sizes would need to be adjusted to take potential extra load though so if you have already prewired that may be an issue?

Originally Posted by twosheds

Hi MM

I was under the impression that a 15A domestic circuit was only permitted one 15A powerpoint. When I had a 15A circuit installed a couple of years ago to run my welder, jointer and bandsaw the electrician installed a 15A single pendant for the jointer and bandsaw in the middle of the shed and a 15A single powerpoint next to the switchboard for the welder (I always weld outside - sawdust and wood shavings don't mix with weld spatter). He told me he wasn't supposed to install two outlets on a single domestic 15A circuit but he made an exception only because I wouldn't be using the welder and the jointer at the same time.

I'm not wanting to put a dampener on your shed fitout (although I am envious) but I am interested in how the circuit breakers would behave if the 15A circuit was overloaded. It would be a real pain in the butt to have them constantly tripping due to excessive load.

Regards
Twosheds

To clarify what I'm about to say, I will call a "powerpoint" the spot where devices are plugged in, and an "outlet" is a single 3 pin plug on that powerpoint (and thus a powerpoint can have 2 outlets).

I had thought about that myself, and specifically checked if we can have a 2 outlet 15A powerpoint that will allow 15A on each outlet. We have an electrician involved in this build, and whilst we're running the cables, he will be doing all checking/connecting and testing.

Your comment of "A 15A circuit is only permitted one powerpoint" matches the advice our electrician has given us.

From my understanding, and given the specifications he has given us, each powerpoint requires it's own cable run back to the switchboard (i.e. a separate circuit for each powerpoint).

From reading your comment, this now makes me think that this is actually a code requirement - from your description he has wired 2 powerpoints (albeit single outlet only) to a single circuit, which thus might not be to code specifications?

If that is the case, then whether each powerpoint has one or two outlets is only dictated by the type/capacity of cable being run and also the circuit breaker in use. We are using, and have had supplied by the electrician, 4mm cable, which I believe is a good step up from the norm. Circuit breakers are yet to be determined.

That said, next time I'm chatting to our electrician, I will double-check on this!

There was a post about a month ago that said the rules re 15A power points bring on a single circuit had changed and more were permitted. Di a search as it had the relevant Standard

Originally Posted by Midnight Man

Your comment of "A 15A circuit is only permitted one powerpoint" matches the advice our electrician has given us. Each powerpoint we are wiring up requires it's own cable run back to the switchboard (i.e. a separate circuit for each powerpoint). In our build, each run is actually using 4mm cable. The "devil" here is the fact that (I think) a powerpoint is considered a single end-point, whether that has 1 or 2 outlets is immaterial, and it comes down to the cable run to that end-point. I am guessing a little here, based on conversations I've had in the past with our electrician, but perhaps some electricians use 2.5mm cable, and that won't support a 30A load (2 x 15A), and hence that is why the comment was made that each powerpoint should only have one outlet?

The issue of "one 15A power point on one circuit" has been discussed many times on this forum and I too was of that opinion based on what several sparkles had told me. Recently a member, who is an also experienced regular reader/user of the ANZ electrical Safety Standards in the building industry, reported that the standards say it is up to the sparky to assess what is being used on the circuit to determine how many 15A outlets can be used. A suggestion that more than one outlet is allowed is that approved double 15A outlets are sold.

Of course the sparky has to trust that the customer is telling him the truth about intended usage and won't subsequently change things around (ie impossible)
Most sparkies don't want to risk these sorts of complications (and some probably want to make a bit extra ) so they go for the easiest option - 1 15A outlet per circuit.
If I was a sparky I would probably do the same thing.

As I have a good knowledge of what is going on with the currents being drawn by my larger machines, AND I very rarely swap any of these machines around - each machine has its own permanent GPO - all 6 of the 15A GPO sin my shed have been installed or replaced with double 15A GPOs. The only one that doesn't is my 2HP Planer thicknesser combo machine which only sees occasional use and can even run on a 10A GPO.

The compressor, DC and bandsaw each have their own ammeters attached so I can see what currents they are drawing. All other machinery current draws have all been measured under load with an ammeter.

Below are examples of a couple of setups.

My Compressor is on one of outlets on a 15A double GPO while the other outlet is used to drive the the automated electronic venting (50 ms every 50 minutes) system for the reticulated compressed air system. The automated venting system draws about 100mA so is nothing compared to the 14.7A max current drawn by the compressor.

My DC and welder/plasma cutter are on the same GPO because I never use both at the same time. The welder/plasma cutter has its own ventilation system running off A 10A GPO and if I were to run the DC while say welding it would gum up the DC filter bags

The 3HP Belt sander and 3HP Bandsaw are on the same 15A GPO. Being a one man shed I can't use both at the same time. I do sometimes leave them both on (and sometime even running, unloaded) but they both draw < 5A each in this state. Even if I leave one running unloaded and load up the other this combo will not draw more than 15A.

The 3HP TS and 3HP router are also on one double 15A GPO. The router is in a router table attached to a TS wing so I never run both at the same time.

This all works if each machine is more or less permanently plugged into a dedicated GPO and you know the current draws of each machine so you can combo them appropriately. It would not be appropriate to plug both a large compressor into the same double 15A GPO, as say a large DC, and have the compressor fire up while the DC is running. If you plan to move larger machines around or swap GPOs often, it makes sense to use single 15A GPOs.

BTW I do the same with the 18 double 10A outlets in my shed. About half of these have 4 or 6 way expander boards on them. Many of my corded tools are hanging up and permanently plugged into either a GPO or expander board outlet.

Small update - we've had another day or so to keep going with progress:

Window framed.jpg

There's a whole bunch more lining to do over the next few weeks!

This is a SHED right? For working in and making mess in?

Originally Posted by riverbuilder

This is a SHED right? For working in and making mess in?

Sort of. Working in, yes. Making mess in, temporarily only.

What can I say - I like "neat and tidy"?

Originally Posted by Bohdan

Depends where you shop. $7.95 or $146.08

That's a good price, they are just under $20 for doubles at the big green shed when I got one last week.
Crocy.

Originally Posted by Old Croc

That's a good price, they are just under $20 for doubles at the big green shed when I got one last week.
Crocy.

The higher priced item is the Clipsal brand while the lower priced item is a no-name. However, that does not necessarily mean the no-name is unsuitable and neither does it mean the Clipsal cannot be found at a better price. I think Bohdan was pointing to the disparity in the market place and the need to shop around.

Regards
Paul